Study on GMO feed in pigs shows increased stomach inflammation
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Daniel C.
Jun 12, 2013, 5:46:55 PM6/12/13
to diy...@googlegroups.com
Article: http://gmojudycarman.org/new-study-shows-that-animals-are-seriously-harmed-by-gm-feed/
Study (PDF warning):
http://gmojudycarman.org/wp-content/uploads/2013/06/The-Full-Paper.pdf
I'll skip the article because it's little more than scare-mongering
and adds nothing to the article. I'm including the text of the
article below. I would be very interested to hear what the list
thinks about this study.
-Dan
A long-term toxicology study on pigs fed a combined genetically
modified (GM) soy and GM maize diet
Judy A. Carman 1,2*, Howard R. Vlieger 3, Larry J. Ver Steeg 4, Verlyn
E. Sneller 3, Garth W. Robinson5**, Catherine A. Clinch-Jones 1, Julie
I. Haynes 6, John W. Edwards 2
1 Institute of Health and Environmental Research, Kensington Park, SA,
Australia.
2 Health and the Environment, School of the Environment, Flinders
University, Bedford
Park, SA, Australia.
3 Verity Farms, Maurice, Iowa, USA.
4 Ana-Tech, Monroe, Wisconsin, USA.
5 Sioux Center Veterinary Clinic, Sioux Center, Iowa, USA.
6 School of Medical Sciences, University of Adelaide, Adelaide, SA, Australia.
* Email: judyc...@ozemail.com.au, judy....@flinders.edu.au.
** Present: Robinson Veterinary Services PC, Sioux Centre, Iowa, USA.
Abstract
A significant number of genetically modified (GM) crops have been
approved to enter
human food and animal feed since 1996, including crops containing
several GM genes
'stacked' into the one plant. We randomised and fed isowean pigs
(N=168) either a mixed
GM soy and GM corn (maize) diet (N=84) or an equivalent non-GM diet
(N=84) in a longterm toxicology study of 22.7 weeks (the normal
lifespan of a commercial pig from
weaning to slaughter). Equal numbers of male and female pigs were
present in each
group. The GM corn contained double and triple-stacked varieties. Feed
intake, weight
gain, mortality and blood biochemistry were measured. Organ weights
and pathology
were determined post-mortem. There were no differences between pigs
fed the GM and
non-GM diets for feed intake, weight gain, mortality, and routine
blood biochemistry
measurements. The GM diet was associated with gastric and uterine
differences in pigs.
GM-fed pigs had uteri that were 25% heavier than non-GM fed pigs
(p=0.025). GM-fed
pigs had a higher rate of severe stomach inflammation with a rate of
32% of GM-fed pigs
compared to 12% of non-GM-fed pigs (p=0.004). The severe stomach
inflammation was
worse in GM-fed males compared to non-GM fed males by a factor of 4.0
(p=0.041), and
GM-fed females compared to non-GM fed females by a factor of 2.2 (p=0.034).
Key words: GMO, GM corn, GM soy, GM animal feed, toxicology, stomach
inflammation,
uterus weight.
Introduction
Genetically modified (GM) crops have entered human food and animal
feed in increasing
amounts since they were commercially released into fields in the USA
in 1996 (USDA,
2011). The main traits in GM crops to date have been to express
proteins for herbicide
tolerance (Ht) and insect resistance (Carman, 2004; USDA, 2011).
Herbicide tolerant
crops are engineered to produce one or more proteins that allow the
crop to survive being
sprayed with a given herbicide. Insect resistant crops are usually
engineered to produce
38 ISSN 1177-4258one or more insecticidal proteins that are toxic to
target insects. The latter proteins are
usually Bt proteins, so named because they are structurally similar to
naturally-occurring
Cry proteins from a soil bacterium, Bacillus thuringiensis (ANZFA,
NDb). Hence these
crops are also called Bt crops.
Of the GM crops planted in the USA, herbicide-tolerant GM soy has been
widely adopted
and now constitutes 94% of the soy planted in the USA (USDA, 2011). GM
corn varieties
have also been widely adopted in the USA (USDA, 2011). They usually
contain Ht or Bt
traits, or a ‘stacked’ combination of them (Pioneer Hi-Bred, 2012).
Prior to the release of a new GM crop into the food supply, the
developer provides food
regulators in many countries with studies it has done on the crop.
These studies often
include animal feeding studies, even though some regulators, such as
Australia's, do not
require them (FSANZ, ND; Carman, 2004), while the USA has a voluntary
system. Many
food regulators do not require any studies to be done on crops
containing several
“stacked” genes if all the genes in the stack have previously been
individually approved
for use in the same kind of plant (EFSA, 2010; FSANZ, 2010).
Consequently, safety
studies on stacked crops are less frequent, even though an analysis of
official data
(USDA, 2011) indicates that over 37% of GM corn varieties currently
planted in the USA
are stacked with both Ht and Bt traits.
There have been a number of reviews of the published literature on the
safety of GM
crops. For example, Flachowsky et al. (2005) and Preston (2005) both
conducted reviews
and both concluded that GM crops were safe for animals and people to
eat. However,
many of the feeding studies reviewed used non-mammals (e.g. birds,
fish) or animals
were fed the crop in a form that humans do not eat (e.g. silage) or
only animal production
outcomes were measured such as body weight, carcass weight, breast
meat yield or milk
production, which may not be indicative of potential human health
outcomes (Carman,
2004). Only a small proportion of published animal feeding studies
have been longer-term
toxicological studies where a GM crop was fed to animals that are
physiologically
comparable to humans, and organs, blood and tissue samples were taken from the
animals and examined to assess if the crop caused any adverse effects.
Two recent reviews of these rarer toxicology-type studies have
recently been published.
Snell et al. (2011) reviewed 12 studies of 90 days or longer duration
and concluded that
GM plants were nutritionally equivalent to non-GM plants and could be
safely used in
food and feed. However, once again, most of the studies reviewed used
animals that
were either not physiologically comparable to humans, or used only
small numbers of
animals. A broader picture is given in a series of three reviews by
Domingo (2000; 2007)
and Domingo & Bordonaba (2011). The first two papers concluded that
there were few
published studies investigating toxicology or health risks, while the
third found that most
of the more recent studies concentrate on only a few GM crops (soy,
corn and rice),
ignoring many other GM crops such as potatoes, peas and tomatoes.
Another review of 19 studies of mammals fed GM soy or maize has recently been
conducted (Séralini et al., 2011). These authors also reviewed the raw
data of some other
authors' 90-day feeding studies. They found some evidence for adverse
liver and kidney
effects from eating some GM crops and concluded that 90-day feeding
studies were
insufficient to evaluate chronic toxicity of GM crops.
Carman, Vlieger, Steeg, Sneller, Robinson, Clinch-Jones, Haynes & Edwards
ISSN 1177-425 39More recently, a highly publicised (e.g. Poulter,
2012), much longer study of two-years'
duration on NK603 herbicide-tolerant corn (which contains one of the
genes fed in the
present study) has been published (Séralini et al. 2012). There were
indications of higher
death rates, more tumours and liver and kidney pathologies in GM-fed rats.
The aim of the present study was to perform a thorough, long-term
toxicology study (for
22.7 weeks, being the normal lifespan of a commercial pig from weaning
to slaughter) on
pigs in a USA commercial piggery in order to compare the effects of
eating either a mixed
GM soy and GM corn diet, or an equivalent diet with non-GM
ingredients. Pigs in the
USA are usually fed a mixed corn and soy diet, containing a high
proportion of GM
varieties. Even though pigs are physiologically similar to humans,
particularly for
gastrointestinal observations, very few toxicology studies have been
conducted on them
for GM crops (Walsh et al., 2012a). In doing this study, we not only
used animals that
were physiologically similar to humans, but we also weighed and
internally examined
organs and took blood for biochemical analysis. We further used a
large enough sample
size (168 pigs, 84 per group) to be able to determine statistical
significance for key
toxicological outcomes. We also used GM crops that are planted in
significant quantities
in the USA (Ht soy, and Ht and Bt corn) and hence are commonly eaten
by pigs and
humans in the USA. We further fed these crops as a mixed diet. Mixed
diets commonly
occur for pigs and humans. This study therefore reflects the effects
of eating GM crops in
the ‘real world’. To our knowledge, this is the first study of its
kind conducted.
Materials and Methods
Animal feed
In accordance with usual commercial USA piggery practice, soy and corn
were obtained
direct from farmers who had grown it commercially. Different GM corn
varieties are
usually co-mingled in farm storage. The corn used in this study
contained 90% DK 42-88
RR YG PL (a triple stack of NK603, MON863 and MON810 genes) with the remainder
being equal quantities of Pannar 5E-900RR (containing NK603), Pannar
4E-705RR/Bt (a
double stack of NK603 and MON810) and Producers 5152 RR (containing NK603).
Therefore, the GM corn that was used was genetically modified to
produce three new
proteins. Two were Bt proteins that protected the plant against insect
attack, while the
third protein provided the plant with tolerance to the herbicide
glyphosate (Testbiotech,
2012; Monsanto, 2012).
Because Roundup ReadyTM (RR) soy is predominant in the GM soy market, this was
used. This crop contains a gene that provides tolerance to the
herbicide glyphosate. GM
DNA analysis (Genetic ID, Fairfield, Iowa, US) confirmed that the GM
corn contained a
combination of NK603, MON863 and MON810 genes (expressing the CP4 EPSPS, Cry
3Bb1 and Cry 1Ab proteins respectively), that the RR soy was 100% RR
soy (expressing
the CP4 EPSPS protein), that the non-GM feed contained a median of
0.4% GM corn and
that the non-GM soy contained a median of 1.6% GM soy. Such GM contamination of
apparent non-GM material is common in the US.
In a similar way to the GM crops used, non-GM soy and non-GM corn were
also obtained
direct from farmers who had grown it commercially for human food and
animal feed.
Isogenic parental varieties of the GM crops, from which the GM crops
were developed,
were not used because they are generally not commercially available to buy.
Furthermore, triple-stacked corn containing all three genes used here
was developed
Journal of Organic Systems, 8(1), 2013
40 ISSN 1177-4258from conventionally cross-breeding several GM crops,
each of which has a non-GM
parent, leading to a multiplicity of isogenic parental varieties that
would need to be used
in combination for a control diet. As the aim of this study was to
compare the effects of
GM and non-GM varieties present in animal feed and human food in the
real world, the
soy and corn for the control diet was instead chosen as a mixture of
non-GM soy and
corn that was destined for animal feed and human food and that came
from the same
geographical area. The GM soy and corn used in this study have been
determined to be
compositionally and substantially equivalent to non-GM varieties of
soy and corn by
government regulators (ANZFA, 2002, NDa, NDb; FSANZ, 2003, 2006) which
indicates
that there should be no phenotypical variation between the GM and
non-GM varieties
used in this study that could influence the outcomes measured in this study.
GM and non-GM corn were both ground using the same cleaned equipment,
size screen
and revolutions per minute to obtain the same particle size. GM and
non-GM soy beans
were also processed on the same type of cleaned equipment - using
Insta-Pro extruders
and expellers, rather than being solvent-extracted, in order to
preserve the identity of the
beans during processing into soybean meal. This process purees the beans and
squeezes out most of the oil, leaving a residual oil content of 8%. In
the process, the
beans are heated to 153oC to 166oC. As pigs grow, they require
different amounts of
nutrients, so six different sub-diets were progressively used. Soy
content decreased from
26.5% to 13.0%, corn increased from 56.4% to 83.8% and protein
decreased from 18.3%
to 13.3% of the diet (Table 1). Ingredients, including supplements,
were those routinely
used by the piggery and were the same between groups. The GM and
non-GM diets had
the same protein, energy, macro- and micro-nutrient contents and only
differed in the use
of GM or non-GM soy and corn. Pigs were fed on a self-feeding,
full-feed basis. The
amount of feed consumed by each group was recorded.
Table 1. Details of the six body-weight-specific sub-diets used
progressively as pigs grew.
Sub-diet number
1 2 3 4 5 6
Pig weight (lb)a
14-25 25-60 60-90 90-130 130-200 200-260
No. days on dietb
39-40 17-18 23-24 24-25 37-38 15-17
Average daily intake (lb) 0.9 2.43 3.45 4.71 6.10 6.78
Protein (%) 18.6 18.0 17.4 16.3 15.2 14.7
Soy (%)c
26.5 25.0 23.4 20.4 17.5 16.0
Corn (%)d
70.0 71.6 73.2 76.3 79.8 81.3
UN premix (%)e
2.5 2.5 — — — —
UG premix (%)f
— — 2.5 2.5 — —
UF premix (%)g
— — — — 2.5 2.5
Boost premix (%)h
0.0025 0.0025 0.001 0.0015 0.0015 0.0015
Extra lysine — — 0.001 0.0005 — —
Extra CaCO3 (%) 0.0075 0.0075 0.006 0.006 0.002 0.002
200 mesh bentonite clay (%) 0.0035 0.0035 0.0035 0.0035 0.0035 0.0035
Carman, Vlieger, Steeg, Sneller, Robinson, Clinch-Jones, Haynes & Edwards
ISSN 1177-425 41a
As the piggery was in the USA, pig diets were changed when pigs
reached a certain weight in pounds.
b Because pig handlers were required to keep to usual piggery
practices and were blinded as to the GM
feeding status of each group of pigs, pigs in each group were changed
from one sub-diet to the next
according to the body weight of the group. Consequently, one group was
often changed to the next sub-diet a
day before the other group. While the GM-fed group spent one day
longer on a particular diet than the non
GM group for three diets, the non-GM group spent a day longer on a
particular diet for the other three diets.
Therefore, there was neither a trend nor a difference in the
progression of the two groups from one diet to
another. Pigs were fed for a total of 158 days if they were
slaughtered on the first of the two slaughter days,
and 159 days if they were slaughtered on the second slaughter day.
c GM soy went into the GM diets and non-GM soy into the non-GM diets.
d GM corn went into the GM diets and non-GM corn into the non-GM diets.
e Ultra Nursery Plus Premix from Advanced Biological Concepts, Osco,
Illinois, containing (as copied directly
from the label) guaranteed amounts of 0.5% crude protein, 6.0% lysine,
0.5% crude fat, 3.0% crude fiber
13.0% to 15% calcium, 13.0% phosphorus, 16.0% to 18.0% sodium
chloride, 10ppm selenium, 1,500 ppm
zinc, 190,000 IU/lb vitamin A, 25,000 IU/lb vitamin D3 and 800 IU/lb
vitamin E. Other ingredients on the label
(not quantified), include: copper, iron, zinc, manganese, choline,
ascorbic acid, niacin, riboflavin, pantothenic
acid, vitamin K, vitamin B12, carotene and iodine.
f Ultra Grower Premix Plus from Advanced Biological Concepts, Osco,
Illinois, containing (as copied directly
from the label) guaranteed amounts of 0.5% crude protein, 1.0% lysine,
0.5% crude fat, 3.0% crude fiber,
15.0% to 17% calcium, 12.0% phosphorus, 15.0% to 17.0% sodium
chloride, 3ppm selenium, 1,500 ppm
zinc, 160,000 IU/lb vitamin A, 22,000 IU/lb vitamin D3 and 800 IU/lb
vitamin E. Other ingredients on the label
(not quantified) include: copper, iron, zinc, manganese, choline,
niacin, riboflavin, pantothenic acid, vitamin K,
vitamin B12, carotene and iodine.
g Ultra Finisher Premix Plus from Advanced Biological Concepts, Osco,
Illinois, containing (as copied directly
from the label) guaranteed amounts of 0.5% crude protein, 3.0% lysine,
0.5% crude fat, 3.0% crude fiber,
18.0% to 20.0% calcium, 10.0% phosphorus, 6.5% to 7.5% sodium
chloride, 3ppm selenium, 4,000 ppm zinc,
125,000 IU/lb vitamin A, 20,000 IU/lb vitamin D3 and 500 IU/lb vitamin
E. Other ingredients on the label (not
quantified) include: copper, iron, zinc, potassium, magnesium,
manganese, choline, ascorbic acid, niacin,
riboflavin, pantothenic acid, vitamin K, vitamin B12, carotene and iodine.
h Natural Boost from Advanced Biological Concepts, Osco, Illinois,
containing (as copied directly from the label)
guaranteed amounts of 10.0% crude protein, 0.005% lysine, 0.005%
methionine, 1.0% crude fat, 24.0%
crude fiber, 40.0% acid detergent fiber, 0.2% to 0.7% calcium, 0.2%
phosphorus, 1.0% to 1.5% sodium
chloride, 0.5% potassium, 500ppm copper, 1,500 ppm zinc, 180,000 IU/lb
vitamin A, 55,000 IU/lb vitamin D3
and 500 IU/lb vitamin E. Other ingredients on the label (not
quantified) include: iron, zinc, magnesium,
manganese, choline, cobalt, ascorbic acid, niacin, riboflavin,
pyridoxine HCl, pantothenic acid, biotin, vitamin
K, vitamin B12, folic acid, carotene and iodine.
Mycotoxin analyses (Midwest Laboratories Inc, Omaha, Nebraska, US)
showed 2.08 ppb
total aflatoxins and 3.0 ppm total fumonisins in a pooled sample of
the GM feed and no
aflatoxins and 1.2 ppm total fumonisins in a pooled sample of the
non-GM feed. No other
mycotoxins were detected. These levels are well below the USA and EU limits for
mycotoxins in pig feed. In addition, according to common industry
practice, a mycotoxin
binding agent (200 mesh bentonite clay) was added to the diets of
young pigs (Table 1).
Animals
Standard commercial Yorkshire-cross piglets were obtained from a
commercial farrowing
facility as a result of crossing Hampshire Duroc males with Yorkshire
Landrace females.
All sows were fed the same diet containing some GM ingredients and
were impregnated
at a similar time to obtain isowean piglets. Male piglets were
neutered at three days of
age in order to fulfill market requirements for meat free of boar-taint.
Unweaned piglets (N=168; average 24 days of age) were transported to
the piggery
nursery and randomly placed into pens of 14 each. Pens were then
randomly allocated to
receive either a GM or non-GM diet. Animals were weighed and then fed
their allocated
diet as their first solid food. After 32 days, pigs were transported
to a different facility for
the ‘growing and finishing’ phase, where they continued on their
allocated diets but were
housed as 42 pigs per pen with outside access. Throughout, pigs were
housed according
Journal of Organic Systems, 8(1), 2013
42 ISSN 1177-4258to usual industry practices, under shelter on
concrete floors. They experienced the
natural daytime/night-time temperature and light/dark cycle.
Data collected from live pigs
Individual weights were recorded weekly and animals were monitored
daily by observers
who were blinded to a pig's dietary group. Daily measurements included
inside and
outside air temperature, air quality, weather conditions, level of
activity of pigs around the
feeder and the appearance of the feeder itself, the level of activity
of the pigs around the
water and the appearance of the water, details of any pigs found dead,
details of any pigs
that were moved away from, or back to, the ‘home pen’ and the reasons
for this (e.g. they
were being harassed by other pigs), level of contentment (measured as
content, irritable
or aggressive), presence of cough or sneeze, the presence of any skin
problems (e.g.
pale or discoloured skin or the presence of rashes or sores), any eye
problems, and the
consistency of the stools (normal, some loose or runny stools, lots of
loose or runny
stools). Blood was taken from the jugular vein of awake pigs according
to standard
industry methods two days before the first pigs were slaughtered. The
blood was taken
from a random subset of pigs in the following pattern to prevent any
time-related bias:
approx. half the pigs in the non-GM-fed group, approx half the pigs in
GM-fed group, the
remainder of the non-GM-fed group, and the remainder of the GM-fed
group. Blood was
centrifuged and serum was removed and frozen. Blood biochemical analyses were
undertaken by Marshfield Clinic Laboratories, Marshfield, WI, USA, who
were blinded to
all aspects of the study. The laboratory's reference range for awake
three to four month
old Yorkshire cross pigs was used as it was most applicable for this study.
Autopsy procedure
When the pigs were 26 weeks old, they were fasted for 18 hours and
transported to a
large commercial abattoir where they were slaughtered according to the
usual, approved
methods of the abattoir on two consecutive days. On each day,
approximately equal
numbers of GM-fed and non-GM-fed pigs were slaughtered to prevent any temporal
between-group bias. Pigs on each day were killed within a few minutes
of each other. The
internal organs were carefully removed to prevent faecal contamination
and placed in
individual identified buckets with 2 litres of cold phosphate-buffered
saline to quickly chill
the organs. Organs were kept under near-freezing conditions until they
were examined by
two licenced, practicing veterinarians with considerable porcine
experience. They were
blinded as to which pigs were fed GM feed. To remove any
between-inspector bias, one
veterinarian examined all the kidneys, hearts, lungs and stomachs
while the other
examined all the livers, spleens, intestines, uteri and ovaries.
Veterinarian comments and
organ weights were recorded by the same person to remove any between-person
measurement bias or recording bias. Where evisceration resulted in
incomplete removal
of an organ, veterinarians determined if disease had caused part of an
organ to adhere to
the chest or abdominal wall and hence remain with the carcass, as well
as the nature of
that disease. The weights of partial organs were not included in
statistical analyses due to
the errors they would have produced. Kidney weights were the sum of
both kidneys per
pig. Ovary weights were the sum of both ovaries per pig except for two
GM-fed pigs
where one ovary was accidentally removed by the abattoir. Here, the
weight of both
ovaries was estimated by doubling the weight of the remaining ovary.
Intestines could not
be weighed or inspected due to the amount of digesta still present in
them, even after 18
hours of fasting, so the external surface of the intestines was
examined for abnormalities
Carman, Vlieger, Steeg, Sneller, Robinson, Clinch-Jones, Haynes & Edwards
ISSN 1177-425 43and any intramural, palpable tissue masses. Organ
weights were analysed as a
percentage of body weights.
In addition to externally examining the organs, veterinarians also
examined the interior of
every kidney using a single, deep transverse cut, every heart by
slicing into both
ventricles and both atria, and every lung using at least two deep cuts
through the dorsal
surface of each lung lobe, and if abnormalities were found, several
more cuts to properly
identify the abnormality and its extent. Every stomach was examined by
cutting it open
along the length of its greatest curvature, washing out the contents
and inspecting the
entire internal surface of the opened-flat stomach, including rugae.
Data analysis
A stomach erosion was defined as an abnormal stomach surface that had
a visible area
of current inflammation and oedema and where the mucosa was starting
to separate (and
which could potentially progress to form an ulcer). The length of any
ulcer was measured
in millimetres. If an ulcer had a clot in it, or showed frank
bleeding, it was recorded as a
bleeding ulcer. If an ulcer was less than 1 mm in length, it was
recorded as a pin-point
ulcer, otherwise as a frank ulcer. When calculating the total length
of ulceration in each
stomach in mm, each pin-point ulcer was numerically rounded to be 1mm
in length.
Stomach inflammation was scored by the attending, blinded veterinarian
as a result of
expertise obtained from numerous pig autopsies and a classification
system developed
as a result of an earlier, preliminary study on pig stomachs. These
stomachs were
obtained from a random sample of pigs from the same abattoir and came from pigs
raised by other commercial pig producers. Inflammation was classified
as nil, mild,
moderate, or severe based on a combination of the area of current
inflammation and level
of redness and swelling. Typical examples of each of the four
categories of inflammation
are shown in Figure 1. For a severe level of inflammation, almost the
whole fundus had to
be swollen and cherry-red in colour.
Data were analysed using the statistical packages SPSS and EpiInfo.
Continuous data
were analysed by removing SPSS-identified extreme outliers, being
those more than
three times the interquartile range away from the lower or upper
quartiles. This
conservative and well-established approach better tests the nature of
the underlying
distribution. Data were then tested for normal distribution using the
Shapiro-Wilk test. If a
normal distribution was found for both dietary groups, data were
expressed as means
and standard deviations and were analysed using parametric methods
(t-test), otherwise
data were expressed as medians and ranges and analysed using non-parametric
methods (Mann-Whitney U test). Categorical data were analysed using
uncorrected chi
squared tests unless an expected cell value was less than five, when
Fisher's Exact was
used.
Journal of Organic Systems, 8(1), 2013
44 ISSN 1177-4258Figure 1. Different levels of stomach inflammation
found (clockwise from top left):
nil (from a non-GM-fed pig, number B41), mild (from a non-GM-fed pig,
number B15), moderate (from a
GM-fed pig, number C34) and severe (from a GM-fed pig, number D22).
Results
There were no statistically significant differences in food intake,
feed conversion ratios,
number or nature of illnesses, number or nature of veterinary
interventions, veterinary
costs or mortality between the non-GM-fed and GM-fed groups of pigs.
Mortalities were
13% and 14% for the non-GM-fed and GM-fed groups respectively, which are within
expected rates for US commercial piggeries. All dead pigs were
autopsied by blinded
veterinarians and deaths were assessed as due to usual commercial
piggery-related
matters and not to their diets. There was also no difference in body
weights between the
two dietary groups, initially, during, or at the end of the
experiment. Initial weights in kg
were : non-GM-fed group: 6.71 + 1.05 (mean + standard deviation);
GM-fed group: 6.87 +
0.97. Final weights were: non-GM-fed group: 100.42 + 22.84; GM-fed
group: 101.75 +
21.92.
Autopsy results
Organ weights were not statistically different between GM-and
non-GM-fed pigs except
for uterine weights (Table 2). After removing one extreme outlier, the
medians of the non
GM-fed (now N=33) and GM-fed (N=37) groups became 0.084% and 0.105% of the body
weight respectively. That is, the median uterus weight of GM-fed pigs,
as a proportion of
Carman, Vlieger, Steeg, Sneller, Robinson, Clinch-Jones, Haynes & Edwards
ISSN 1177-425 45body weight, was 25% higher than that of non-GM-fed
pigs, which was statistically
significant (p=0.025).
There was no difference in the disease status of organs between the
two groups of pigs
except for the level of inflammation in the stomachs of the pigs
(Table 3, Figure 1). For
non-GM-fed pigs, stomach inflammation was concentrated in the mild and moderate
range, whereas GM-fed pigs showed much more severe inflammation
(p=0.004). GM-fed
pigs showed severe stomach inflammation at a rate of 2.6 times that of
non-GM-fed pigs
(95% confidence interval = 1.29-5.21) (Table 3). This occurred in both
male (p=0.041)
and female (p=0.034) pigs (Table 4). We found severe stomach
inflammation in 22.2% of
male pigs fed the GM diet and in 41.7% of female pigs fed the GM diet
(compared to
5.6% and 18.9%, respectively, in pigs fed the non-GM diet (Table 4).
Blood biochemistry
Blood biochemistry results are given in Table 5. Aspartate transaminase (AST),
potassium and creatine kinase (CK) were not statistically analysed
because they were
raised substantially in both dietary groups due to the way blood was
collected and hence
they were unable to reflect any effect of feeding a GM diet. AST and
potassium were
raised because the collection needle was pushed through muscle, while
CK was raised
due to the pigs being alert and restrained while blood was taken.
While bicarbonate can
increase if pigs pant or squeal unduly during blood taking, no pigs
recorded a bicarbonate
concentration higher than the reference range (Table 6), so this
variable was retained in
analyses.
To determine if feeding the GM diet was associated with a clinically abnormal
biochemistry profile, the proportion of pigs in each dietary group
that lay above (or below)
the reference (normal) range were then compared (Table 6). No
statistically significant
differences were found. The means or medians of the biochemical
variables were also
compared. No significant differences were found (Table 5).
The analyses of several biochemical variables were confounded by the level of
haemolysis in the blood sample. Haemolysis can be a problem when
taking blood from
alert animals, and in non-laboratory settings due to lag times between
sampling and
centrifuging blood. Haemolysis was reported as nil, mild, moderate or
severe by the
laboratory. Total bilirubin, urea nitrogen, creatinine, phosphorus,
calcium, sodium,
chloride, bicarbonate, and anion gap were found to be significantly
correlated with the
level of haemolysis (results not shown) and hence haemolysis was regarded as a
confounder for these variables. Spearman's rho test was used as a
measure of the
association rather than the Pearson correlation co-efficient as it is
less sensitive to
outliers and does not assume normality. These biochemical variables
then underwent
multiple linear regression to control for the effect of haemolysis. As
known confounders
should be controlled-for, even if they do not appear as actual
confounders in initial
studies, glucose also underwent this process. No biochemical variable
was found to have
a significant relationship to the diet with the level of haemolysis
controlled-for (results not
shown). Consequently, no biochemical differences were found between
non-GM-fed and
GM-fed pigs. However, the concentration of GGT, which is a measure of
liver heath, was
16% lower in GM-fed pigs than non-GM-fed pigs and this result was on
the borderline of
statistical significance (Table 5).
Journal of Organic Systems, 8(1), 2013
46 ISSN 1177-4258Table 2. Organ weights (as a percentage of body
weight) - descriptive statistics of raw data
and statistical comparisons of extreme outlier-removed data.
Non-GM-fed GM-fed
Statistical
comparison
of dietary
groups
na
Mean SDb
Median Min Max na
Mean SDb
Median Min Max Test
usedc
pd
Kidneys 66 0.32 0.066 0.31 0.19 0.66 68 0.33 0.057 0.32 0.16 0.56 t 0.51
Heart 69 0.40 0.065 0.40 0.27 0.63 69 0.41 0.059 0.40 0.27 0.61 MW 0.79
Liver 71 1.81 0.342 1.77 1.27 3.20 72 1.79 0.348 1.71 1.25 3.16 MW 0.45
Spleen 73 0.16 0.033 0.16 0.11 0.33 71 0.16 0.032 0.15 0.093 0.30 t 0.40
Lung 67 0.91 0.241 0.87 0.58 2.00 68 0.98 0.315 0.94 0.57 2.52 MW 0.20
Stomach 73 0.62 0.130 0.57 0.42 0.99 71 0.64 0.129 0.60 0.44 1.01 MW 0.26
Uterus 34 0.10 0.048 0.086 0.040 0.31 37 0.12 0.053 0.105 0.036 0.244 MW 0.025*
Ovaries 36 0.0085 0.0027 0.0081 0.0040 0.019 36 0.0086 0.0023 0.0084
0.0047 0.014 t 0.38
a An organ was not included in the analysis if adhesions caused only a
partial organ to remain with the viscera,
due to the errors inclusion would have caused.
b Standard deviation
c After tests for normality, groups were compared by 2-tailed t-test
if data from both dietary groups were
normally distributed, Mann Whitney U test (MW) otherwise.
d* p<0.05 to 0.01, ** p<0.01 to 0.001, *** p<0.001
Table 3. The proportion of pigs in each dietary group with adverse
findings on gross
pathology
Organ Condition
Proportion with condition
Relative
risk of
condition
in GM-fed
pigs
95%
confidence
interval of
the relative
risk
pa
Organ Condition
Non-GM-fed GM-fed Relative
risk of
condition
in GM-fed
pigs
95%
confidence
interval of
the relative
risk
pa
Organ Condition No.
N=73 %
No.
N=72 %
Relative
risk of
condition
in GM-fed
pigs
95%
confidence
interval of
the relative
risk
pa
Kidney Any abnormality 0 0.0 0 0.0 —b
—b
—b
Heart Any abnormalityc
11 15.1 5 6.9 0.46 0.17-1.26 0.119
Liver Any abnormalityd
6 8.2 3 4.2 0.51 0.13-1.95 0.494
Spleen Any abnormalitye
3 4.1 2 2.8 0.68 0.12-3.93 1.000
Lung
Pneumoniaf
42 57.5 43 59.7 1.04 0.79-1.36 0.789
Lung Fibrous pleuritis or pericarditis 9 12.3 4 5.6 0.45 0.15-1.40 0.153 Lung
Abnormal lymph nodesg
13 17.8 16 22.2 1.25 0.65-2.40 0.506
Stomach
Nil inflammation 4 5.4 8 11.1 2.03 0.64-6.44 0.218
Stomach
Mild inflammation 31 42.5 23 31.9 0.75 0.49-1.16 0.190
Stomach
Moderate inflammation 29 39.7 18 25.0 0.63 0.39-1.03 0.058
Stomach
Severe inflammation 9 12.3 23 31.9 2.59 1.29-5.21 0.004**
Stomach
Erosion(s) 63 86.3 58 80.6 0.93 0.81-1.08 0.352
Stomach
Pin-point ulcer(s) 13 17.8 9 12.5 0.70 0.32-1.54 0.373
Stomach
Frank ulcer(s) 15 20.5 17 23.6 1.15 0.62-2.12 0.657
Stomach
Bleeding ulcer(s) 0 0.0 2 2.8 —b
—b
0.245
Intestines Any abnormality 0 0.0 0 0.0 —b
—b
—b
Uterus Filled with fluidh
0
i
0.0 2
j
5.6 —b
—b
0.493
Ovary Any abnormality 0
k
0.0 0
l
0.0 —b
—b
—b
Carman, Vlieger, Steeg, Sneller, Robinson, Clinch-Jones, Haynes & Edwards
ISSN 1177-425 47a Uncorrected chi-square test unless an expected cell
value was less than five, when Fisher exact test (2-tailed)
was used. * p<0.05 to 0.01, ** p<0.01 to 0.001, *** p<0.001
b No statistic could be calculated because one or more cells contained zeros.
c Adhesions and/or fibrous pericarditis and/or scar tissue.
d Adhesions and/or fibrinous tags and/or the presence of fibrin.
e Adhesions and/or fibrinous tags.
f Consolidating bronchopneumonia of the cranial ventral lung lobe(s)
and/or caudal lobe(s).
g Haemorrhagic and/or swollen bronchial lymph node(s).
h When two uteri were removed from neighbouring organs, fluid oozed from them.
i N=36. Of 37 females, one had a congenital defect. It had only the
beginnings of a uterine tract and no uterus or
ovaries.
j N=36.
k N=36. Of 37 females, one had a congenital defect. It had only the
beginnings of a uterine tract and no uterus
or ovaries.
l N=35. Of 36 females, one had a uterus but no ovaries, which were
removed by accident during slaughter and
retained by the slaughterhouse.
Table 4. Stomach inflammation by gender.
Gender Level of
stomach
inflammation
Proportion with condition
Relative
risk of
condition
in GM-fed
pigs
95%
confidence
interval of the
relative risk
Gender Level of pa
stomach
inflammation
Non-GM-fed GM-fed
Relative
risk of
condition
in GM-fed
pigs
95%
confidence
interval of the
relative risk
Gender Level of pa
stomach
inflammation No.b
% No.c
%
Relative
risk of
condition
in GM-fed
pigs
95%
confidence
interval of the
relative risk
pa
Males
Nil 1 2.8 4 11.1 4.00 0.47-34.07 0.357
Malesaes Mild 16 44.4 12 33.3 0.75 0.42-1.35 0.334
Moderate 17 47.2 12 33.3 0.71 0.40-1.26 0.230
Males
Severe 2 5.6 8 22.2 4.00 0.91-17.56 0.041*
Females
Nil 3 8.1 4 11.1 1.37 0.33-5.70 0.711
Females Females Mild 15 40.5 11 30.6 0.75 0.40-1.41 0.373
Moderate 12 32.4 6 16.7 0.51 0.22-1.22 0.118
Females
Severe 7 18.9 15 41.7 2.20 1.02-4.76 0.034*
a Uncorrected chi-square test unless an expected cell value was less
than five, when Fisher exact test (2-tailed)
was used. * p<0.05 to 0.01, ** p<0.01 to 0.001, *** p<0.001
b N=36 for males, N=37 for females.
c N=36 for males, N=36 for females.
Journal of Organic Systems, 8(1), 2013
48 ISSN 1177-4258Table 5. Blood biochemistry descriptive statistics of
raw data and statistical comparisons of
extreme outlier-removed data.
Non-GM-fed GM-fed Reference rangea
Statistical
comparison
of dietary
groups
N Medianb
(Mean)
Rangeb
(SD)
N Medianb
(Mean)
Rangeb
(SD)
Standard
(asleep)c
Awake
(Yorkshire
X)d
Test
usede
pf
Glucose (mg/dL) 39 89.0 58 – 109 38 90.5 52 – 111 85 – 150 58.0 – 197.0 MW 0.81
ASTg
(U/L) 39 60.0 21 – 2757 38 57.0 12 – 1724 32 – 84 0.0 – 45.0 MW 0.72
Total bilirubin (mg/
dL)
39 0.10 0.1 – 0.3 38 0.10 0.1 – 0.3 0.0 – 1.0 0.1 – 0.2 MW 0.76
Cholesterol (mg/dL)39 100.0 56 – 140 38 100.0 55 – 125 36 – 54 50.0 –
92.0 MW 0.85
Total protein (g/dL) 39 (6.48) (0.95) 38 (6.63) (0.91) 7.9 – 8.9 5.1 –
6.9 t 0.16
Albumin (g/dL) 39 4.00 1.7 – 4.7 38 4.10 1.7 – 4.8 1.9 – 3.3 3.0 – 4.4 MW 0.59
Urea nitrogen (mg/
dL)
39 11.0 5 – 22 38 12.0 8 – 29 10 – 30 4.3 – 12.7 MW 0.30
Creatinine (mg/dL) 39 0.90 0 – 1 38 0.70 0 – 1 1.0 – 2.7 0.9 – 1.9 MW 0.21
Phosphorus (mg/
dL)
39 (9.1) (1.5) 38 (9.1) (1.5) 5.3 – 9.6 6.2 – 9.2 t 0.99
Calcium (mg/dL) 39 10.70 5.5 – 11.3 38 10.50 5.1 –12.0 7.1 –11.6 9.1 –
10.8 MW 0.94
Sodium (mmol/L) 37 140.0 98 – 148 37 140.0 98 – 145 135 - 150
132.0–144.0 MW 0.60
Potassium (mmol/
L)
38 6.35 4.6 – 13.9 37 6.40 4.3 –16.3 4.4 – 6.7 3.4 – 5.0 MW 0.56
Chloride (mmol/L) 38 97.0 67 – 104 37 98.0 66 – 102 94 – 106 94.0 –
103.0 MW 0.86
Bicarbonate (mmol/
L)
39 33.0 19 – 37 38 33.5 18 – 37 18 – 27 28.0 – 37.0 MW 0.44
CKh
(U/L) 39 2416.0 214 –22500 38 1960.0 10 –22500 61 –1251264.0–1247.0 MW 0.73
GGTi
(U/L) 39 (35.1) (18.4) 38 (29.5) (18.1) 10 – 60 0.0 – 60.0 t 0.05
Anion gap (mmol/
L)j
37 16.0 12 – 23 37 15.0 11 – 27 – – MW 0.61
a From Marshfield Clinic, Marshfield, WI, USA.
b Medians and ranges are reported for non-parametric comparisons,
means and standard deviations for
parametric comparisons.
c Marshfield Clinic's usual reference range. Pigs were anaesthetised
to obtain blood.
d Marshfiled Clinic's reference range for awake, 3-4 month-old
Yorkshire cross pigs. This was used as it is much
more applicable to this study.
e After tests for normality, groups were compared by two-tailed t-test
if data from both dietary groups were
normally distributed, Mann Whitney U test (MW) otherwise.
f * p<0.05 to 0.01, ** p<0.01 to 0.001, *** p<0.001
g Aspartate transaminase.
h Creatine kinase.
i Gamma-glutamyl transferase.
j There is no laboratory reference range for anion gap. Sorbitol
dehydrogenase results were not given by the lab
on this occasion.
Carman, Vlieger, Steeg, Sneller, Robinson, Clinch-Jones, Haynes & Edwards
ISSN 1177-425 49Table 6. Biochemical variables compared to the reference rangea
to determine clinical
significance.
Biochemical
variable
Number (%) above or below reference range
Biochemical
variable
Non-GM-fed (N=39) GM-fed (N=38)
Biochemical
variable Above
reference
range
Below
reference
range
Above
reference
range
Below
reference
range
Glucose 0 (0) 0 (0) 0 (0) 2 (5)
ASTb 23 (59) —c
24 (63) —c
Total bilirubin 1(3) 0 (0) 1 (3) 0 (0)
Cholesterol 29 (74) 0 (0) 28 (74) 0 (0)
Total protein 10 (26) 4 (10) 17 (45) 3 (8)
Albumin 7 (18) 5 (13) 3 (8) 5 (13)
Urea nitrogen 10 (26) 0 (0) 16 (42) 0 (0)
Creatine 0 (0) 18 (46) 0 (0) 23 (61)
Phosphorus 12 (31) 2 (5) 16 (42) 1 (3)
Calcium 10 (26) 9 (23) 14 (37) 6 (16)
Sodium 2 (5)d
4 (11)d
0 (0)d
4 (11)d
Potassium 34 (89)e
0 (0)e
36 (97)d
0 (0)d
Chloride 1 (3)e
7 (18)e
0 (0)d
4 (11)d
Bicarbonate 0 (0) 5 (13) 0 (0) 5 (13)
CKf
24 (62) 2 (5) 27 (71) 1 (3)
GGTg 2 (5) —c
1 (3) —c
a Awake Yorkshire cross pig reference range from Marshfield Clinic,
Marshfield, WI, USA. Anion gap has no
reference range so was not included in the table.
b Aspartate transaminase.
c It was not possible for a pig to record a concentration below the
bottom of the reference range, which was
zero.
d N=37.
e N=38.
f Creatine kinase.
g Gamma-glutamyl transferase.
Discussion
In this study, we found that female pigs fed the GM diet had median
uterine weights that
were 25% greater than non-GM-fed pigs (p=0.025). This result is
attributed to the
difference in diet as other variables were controlled for, including
the presence of
mycotoxins, and possible confounders such as infectious diseases,
animal husbandry
considerations and various forms of bias such as temporal, between-person,
measurement or recording bias, as these were all controlled-for. The
concentration of
mycotoxins in the feed was insignificant, both dietary groups received
the same nutrients
and care, the care complied with industry standards, and all those
doing laboratory
analyses and weighing, caring for, slaughtering and doing autopsies on
pigs were blinded
as to the dietary group of each pig.
Journal of Organic Systems, 8(1), 2013
50 ISSN 1177-4258The reported difference in uterine weight warrants
further investigation in future studies
because such a biologically significant difference in uterine weights
may reflect
endometrial hyperplasia or carcinoma, endometritis, endometriosis, adenomyosis,
inflammation, a thickening of the myometrium, or the presence of
polyps. The uteri from
two GM-fed pigs were full of fluid compared to nil from non-GM-fed
pigs (Table 3) which
may be linked to pathology. The link between an increase in uterine
weights and GM
feeding is supported by other authors (Brasil et al., 2009) who found
that GM soy-fed rats
had a statistically significant 59% increase in the density of the
uterine endometrial
glandular epithelium compared to rats fed an equivalent organic soy
diet. Further studies
should include histology, blood oestrogen, progesterone and cytokine
concentrations, and
which GM crop(s) and their GM protein products may, or may not, be
involved. As this
study used neutered males, further studies are required to investigate
any potential effect
of these crops on male reproduction. Multigenerational reproductive
studies should also
be considered.
In this study, a diet of GM feed had no effect on stomach erosions or
ulceration but had a
significant effect on inflammation. Pigs fed the mixed GM soy and GM
corn diet showed
2.6 times the rate of severe stomach inflammation compared to non-GM
fed pigs. This
biologically significant finding was statistically significant
(p=0.004). GM-fed male pigs
showed severe stomach inflammation at a rate of 4.0 times that of the
non GM fed male
pigs (p=0.041); and female pigs showed a rate of severe stomach
inflammation that was
2.2 the rate of the non-GM fed female pigs (p=0.034).
The pig industry uses finely-ground feed to maximise feed efficiency
which can increase
inflammation and ulceration of the stomach (Wolf, 2010). We therefore
controlled the
grind size, removing it as a confounder. Hence our results show that
these GM crops
were associated with stomach inflammation that was additional to any
that may be
caused by particle size. The result is attributed to the difference in
diet, since the
presence of mycotoxins, possible confounders such as infectious
diseases, animal
husbandry considerations or temporal, between-person, measurement and
recording bias
were controlled across the two groups.
One explanation for the inflammation results could lie with the Cry
3Bb1 and Cry 1Ab
proteins that these GM corn varieties are engineered to produce. They
act as insecticides
by inducing pore formation and disintegration of the gut tissue (Spok
et al., 2007) of
certain grubs that attack corn plants. It has been argued that these
proteins cannot harm
the gastrointestinal tract of mammals because mammals lack the necessary gut
environment and receptors (ANZFA, 2000). However, Vazquez-Padron et
al. (2000) found
six proteins in the mouse small intestine that could bind to a Cry
protein (Cry 1Ac).
Furthermore, when the Cry protein bound to these proteins, it resulted in
hyperpolarisation of the intestine, which is consistent with the
formation of cationic
channels, as occurs in the insect gut (Vazquez-Padron et al., 2000).
In addition, an
independent in vivo study found structural changes and hyperplasia in
the ileum of mice
fed a Cry protein for two weeks (Fares & El-Sayed, 1998). Chowdhury et
al. (2003) and
Walsh et al. (2012b) found the Cry1Ab protein (which was present in
the feed in our
study) throughout the digestive tract of pigs. Chowdhury et al. (2003)
found the protein
(and sections of the gene that codes for it) in the stomach, duodenum,
ileum, caecum
and rectum of pigs fed Bt11 corn for four weeks, while Walsh et al.
(2012b) found the
protein in the stomach, caecum and colon of pigs fed MON810 corn for
110 days (they
Carman, Vlieger, Steeg, Sneller, Robinson, Clinch-Jones, Haynes & Edwards
ISSN 1177-425 51appear not to have looked in the rectum), indicating
that this protein is resistant to
digestion in pigs. In our study, stomach inflammation may be due to
one or both of the
Cry proteins fed in the study and future studies may provide answers.
The findings in this study are conservative since the non-GM diet pigs
were exposed,
albeit minimally, to potential GMO impacts. The presence of small amounts of GM
material in the non-GM feed, using out-bred animals, piglets from
GM-fed sows, and
performing the study in a commercial setting (including the potential
exposure of the pigs
to any infectious diseases common to US commercial pigs and taking
blood on site)
could be expected to reduce any differences between the two dietary groups.
We found that our key findings were not reflected in the standard
biochemical tests often
undertaken by researchers in this area, probably because such tests
provide a poor
measure of inflammation and matters associated with uterine size. We
suggest that the
following may be better measures: the red blood cell count and
haematocrit to measure
anaemia and iron deficiency from possible blood loss, C-reactive
protein and white blood
cell count to measure inflammation, and oestrogen and progesterone.
In addition, if an autopsy is done at the end of a GM crop feeding
experiment, this often
involves only a visual inspection of the exterior of organs without
weighing them.
However by weighing organs we found a significant 25% increase in
uterine weights in
the GM-fed pigs. Moreover, where organs are weighed in such studies,
they are often not
examined internally (Carman, 2004) and such an approach would preclude
finding the
stomach inflammation reported in the present study.
The present study is an observational study of the action of a mixture
of GM crops on the
health of pigs, versus a comparable non-GM diet. Future work will
investigate individual
GM crops, will involve histopathology, and will consider mechanisms
for reported group
differences.
Conclusion
Pigs fed a GMO diet exhibited heavier uteri and a higher rate of severe stomach
inflammation than pigs fed a comparable non-GMO diet. Given the
widespread use of
GMO feed for livestock as well as humans this is a cause for concern.
The results
indicate that it would be prudent for GM crops that are destined for
human food and
animal feed, including stacked GM crops, to undergo long-term animal
feeding studies
preferably before commercial planting, particularly for toxicological
and reproductive
effects. Humans have a similar gastrointestinal tract to pigs, and
these GM crops are
widely consumed by people, particularly in the USA, so it would be be
prudent to
determine if the findings of this study are applicable to humans.
Conflict of Interest Statement
The authors declare that there are no conflicts of interest.
Acknowledgments
This research was funded by the Institute of Health and Environmental
Research (IHER) and Verity
Farms. Funding for IHER's involvement came from the Government of
Western Australia (WA) and
George Kailis. Funding for Verity Farm's involvement came from Verity
Farms. We gratefully
Journal of Organic Systems, 8(1), 2013
52 ISSN 1177-4258acknowledge the following people for their assistance
(alphabetical order): Elaine Attwood, Susan
Bardocz, Ed Boote, Kim Chance, Nick Costa, John Coveney, Philip
Davies, Colton Eckmann,
Peggy Eckmann, Rick Eckmann, John Fagan, Leanne Good, Gene Haverdink,
Ryan Hawkins, Jack
Heinemann, George Kailis, Britney Kaufman, Kiley Kaufman, Ron Kaufman,
Stephanie Kaufman,
David Kiel, Michelle Koonce, Ed McGuire, Mike McMullan, Julie Newman,
Arpad Pusztai, Patrick
Quinn, Wayne Searcy, Brian Setchell, SiouxPreme Packing Co., Jeffrey
Smith, Duane Spader,
Rosemary Stanton, David Vlieger, Pamela Vlieger, Rachael Vlieger, John
Ymker, Irena Zdziarski.
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Journal of Organic Systems, 8(1), 2013
54 ISSN 1177-4258
Study (PDF warning):
http://gmojudycarman.org/wp-content/uploads/2013/06/The-Full-Paper.pdf
I'll skip the article because it's little more than scare-mongering
and adds nothing to the article. I'm including the text of the
article below. I would be very interested to hear what the list
thinks about this study.
-Dan
A long-term toxicology study on pigs fed a combined genetically
modified (GM) soy and GM maize diet
Judy A. Carman 1,2*, Howard R. Vlieger 3, Larry J. Ver Steeg 4, Verlyn
E. Sneller 3, Garth W. Robinson5**, Catherine A. Clinch-Jones 1, Julie
I. Haynes 6, John W. Edwards 2
1 Institute of Health and Environmental Research, Kensington Park, SA,
Australia.
2 Health and the Environment, School of the Environment, Flinders
University, Bedford
Park, SA, Australia.
3 Verity Farms, Maurice, Iowa, USA.
4 Ana-Tech, Monroe, Wisconsin, USA.
5 Sioux Center Veterinary Clinic, Sioux Center, Iowa, USA.
6 School of Medical Sciences, University of Adelaide, Adelaide, SA, Australia.
* Email: judyc...@ozemail.com.au, judy....@flinders.edu.au.
** Present: Robinson Veterinary Services PC, Sioux Centre, Iowa, USA.
Abstract
A significant number of genetically modified (GM) crops have been
approved to enter
human food and animal feed since 1996, including crops containing
several GM genes
'stacked' into the one plant. We randomised and fed isowean pigs
(N=168) either a mixed
GM soy and GM corn (maize) diet (N=84) or an equivalent non-GM diet
(N=84) in a longterm toxicology study of 22.7 weeks (the normal
lifespan of a commercial pig from
weaning to slaughter). Equal numbers of male and female pigs were
present in each
group. The GM corn contained double and triple-stacked varieties. Feed
intake, weight
gain, mortality and blood biochemistry were measured. Organ weights
and pathology
were determined post-mortem. There were no differences between pigs
fed the GM and
non-GM diets for feed intake, weight gain, mortality, and routine
blood biochemistry
measurements. The GM diet was associated with gastric and uterine
differences in pigs.
GM-fed pigs had uteri that were 25% heavier than non-GM fed pigs
(p=0.025). GM-fed
pigs had a higher rate of severe stomach inflammation with a rate of
32% of GM-fed pigs
compared to 12% of non-GM-fed pigs (p=0.004). The severe stomach
inflammation was
worse in GM-fed males compared to non-GM fed males by a factor of 4.0
(p=0.041), and
GM-fed females compared to non-GM fed females by a factor of 2.2 (p=0.034).
Key words: GMO, GM corn, GM soy, GM animal feed, toxicology, stomach
inflammation,
uterus weight.
Introduction
Genetically modified (GM) crops have entered human food and animal
feed in increasing
amounts since they were commercially released into fields in the USA
in 1996 (USDA,
2011). The main traits in GM crops to date have been to express
proteins for herbicide
tolerance (Ht) and insect resistance (Carman, 2004; USDA, 2011).
Herbicide tolerant
crops are engineered to produce one or more proteins that allow the
crop to survive being
sprayed with a given herbicide. Insect resistant crops are usually
engineered to produce
38 ISSN 1177-4258one or more insecticidal proteins that are toxic to
target insects. The latter proteins are
usually Bt proteins, so named because they are structurally similar to
naturally-occurring
Cry proteins from a soil bacterium, Bacillus thuringiensis (ANZFA,
NDb). Hence these
crops are also called Bt crops.
Of the GM crops planted in the USA, herbicide-tolerant GM soy has been
widely adopted
and now constitutes 94% of the soy planted in the USA (USDA, 2011). GM
corn varieties
have also been widely adopted in the USA (USDA, 2011). They usually
contain Ht or Bt
traits, or a ‘stacked’ combination of them (Pioneer Hi-Bred, 2012).
Prior to the release of a new GM crop into the food supply, the
developer provides food
regulators in many countries with studies it has done on the crop.
These studies often
include animal feeding studies, even though some regulators, such as
Australia's, do not
require them (FSANZ, ND; Carman, 2004), while the USA has a voluntary
system. Many
food regulators do not require any studies to be done on crops
containing several
“stacked” genes if all the genes in the stack have previously been
individually approved
for use in the same kind of plant (EFSA, 2010; FSANZ, 2010).
Consequently, safety
studies on stacked crops are less frequent, even though an analysis of
official data
(USDA, 2011) indicates that over 37% of GM corn varieties currently
planted in the USA
are stacked with both Ht and Bt traits.
There have been a number of reviews of the published literature on the
safety of GM
crops. For example, Flachowsky et al. (2005) and Preston (2005) both
conducted reviews
and both concluded that GM crops were safe for animals and people to
eat. However,
many of the feeding studies reviewed used non-mammals (e.g. birds,
fish) or animals
were fed the crop in a form that humans do not eat (e.g. silage) or
only animal production
outcomes were measured such as body weight, carcass weight, breast
meat yield or milk
production, which may not be indicative of potential human health
outcomes (Carman,
2004). Only a small proportion of published animal feeding studies
have been longer-term
toxicological studies where a GM crop was fed to animals that are
physiologically
comparable to humans, and organs, blood and tissue samples were taken from the
animals and examined to assess if the crop caused any adverse effects.
Two recent reviews of these rarer toxicology-type studies have
recently been published.
Snell et al. (2011) reviewed 12 studies of 90 days or longer duration
and concluded that
GM plants were nutritionally equivalent to non-GM plants and could be
safely used in
food and feed. However, once again, most of the studies reviewed used
animals that
were either not physiologically comparable to humans, or used only
small numbers of
animals. A broader picture is given in a series of three reviews by
Domingo (2000; 2007)
and Domingo & Bordonaba (2011). The first two papers concluded that
there were few
published studies investigating toxicology or health risks, while the
third found that most
of the more recent studies concentrate on only a few GM crops (soy,
corn and rice),
ignoring many other GM crops such as potatoes, peas and tomatoes.
Another review of 19 studies of mammals fed GM soy or maize has recently been
conducted (Séralini et al., 2011). These authors also reviewed the raw
data of some other
authors' 90-day feeding studies. They found some evidence for adverse
liver and kidney
effects from eating some GM crops and concluded that 90-day feeding
studies were
insufficient to evaluate chronic toxicity of GM crops.
Carman, Vlieger, Steeg, Sneller, Robinson, Clinch-Jones, Haynes & Edwards
ISSN 1177-425 39More recently, a highly publicised (e.g. Poulter,
2012), much longer study of two-years'
duration on NK603 herbicide-tolerant corn (which contains one of the
genes fed in the
present study) has been published (Séralini et al. 2012). There were
indications of higher
death rates, more tumours and liver and kidney pathologies in GM-fed rats.
The aim of the present study was to perform a thorough, long-term
toxicology study (for
22.7 weeks, being the normal lifespan of a commercial pig from weaning
to slaughter) on
pigs in a USA commercial piggery in order to compare the effects of
eating either a mixed
GM soy and GM corn diet, or an equivalent diet with non-GM
ingredients. Pigs in the
USA are usually fed a mixed corn and soy diet, containing a high
proportion of GM
varieties. Even though pigs are physiologically similar to humans,
particularly for
gastrointestinal observations, very few toxicology studies have been
conducted on them
for GM crops (Walsh et al., 2012a). In doing this study, we not only
used animals that
were physiologically similar to humans, but we also weighed and
internally examined
organs and took blood for biochemical analysis. We further used a
large enough sample
size (168 pigs, 84 per group) to be able to determine statistical
significance for key
toxicological outcomes. We also used GM crops that are planted in
significant quantities
in the USA (Ht soy, and Ht and Bt corn) and hence are commonly eaten
by pigs and
humans in the USA. We further fed these crops as a mixed diet. Mixed
diets commonly
occur for pigs and humans. This study therefore reflects the effects
of eating GM crops in
the ‘real world’. To our knowledge, this is the first study of its
kind conducted.
Materials and Methods
Animal feed
In accordance with usual commercial USA piggery practice, soy and corn
were obtained
direct from farmers who had grown it commercially. Different GM corn
varieties are
usually co-mingled in farm storage. The corn used in this study
contained 90% DK 42-88
RR YG PL (a triple stack of NK603, MON863 and MON810 genes) with the remainder
being equal quantities of Pannar 5E-900RR (containing NK603), Pannar
4E-705RR/Bt (a
double stack of NK603 and MON810) and Producers 5152 RR (containing NK603).
Therefore, the GM corn that was used was genetically modified to
produce three new
proteins. Two were Bt proteins that protected the plant against insect
attack, while the
third protein provided the plant with tolerance to the herbicide
glyphosate (Testbiotech,
2012; Monsanto, 2012).
Because Roundup ReadyTM (RR) soy is predominant in the GM soy market, this was
used. This crop contains a gene that provides tolerance to the
herbicide glyphosate. GM
DNA analysis (Genetic ID, Fairfield, Iowa, US) confirmed that the GM
corn contained a
combination of NK603, MON863 and MON810 genes (expressing the CP4 EPSPS, Cry
3Bb1 and Cry 1Ab proteins respectively), that the RR soy was 100% RR
soy (expressing
the CP4 EPSPS protein), that the non-GM feed contained a median of
0.4% GM corn and
that the non-GM soy contained a median of 1.6% GM soy. Such GM contamination of
apparent non-GM material is common in the US.
In a similar way to the GM crops used, non-GM soy and non-GM corn were
also obtained
direct from farmers who had grown it commercially for human food and
animal feed.
Isogenic parental varieties of the GM crops, from which the GM crops
were developed,
were not used because they are generally not commercially available to buy.
Furthermore, triple-stacked corn containing all three genes used here
was developed
Journal of Organic Systems, 8(1), 2013
40 ISSN 1177-4258from conventionally cross-breeding several GM crops,
each of which has a non-GM
parent, leading to a multiplicity of isogenic parental varieties that
would need to be used
in combination for a control diet. As the aim of this study was to
compare the effects of
GM and non-GM varieties present in animal feed and human food in the
real world, the
soy and corn for the control diet was instead chosen as a mixture of
non-GM soy and
corn that was destined for animal feed and human food and that came
from the same
geographical area. The GM soy and corn used in this study have been
determined to be
compositionally and substantially equivalent to non-GM varieties of
soy and corn by
government regulators (ANZFA, 2002, NDa, NDb; FSANZ, 2003, 2006) which
indicates
that there should be no phenotypical variation between the GM and
non-GM varieties
used in this study that could influence the outcomes measured in this study.
GM and non-GM corn were both ground using the same cleaned equipment,
size screen
and revolutions per minute to obtain the same particle size. GM and
non-GM soy beans
were also processed on the same type of cleaned equipment - using
Insta-Pro extruders
and expellers, rather than being solvent-extracted, in order to
preserve the identity of the
beans during processing into soybean meal. This process purees the beans and
squeezes out most of the oil, leaving a residual oil content of 8%. In
the process, the
beans are heated to 153oC to 166oC. As pigs grow, they require
different amounts of
nutrients, so six different sub-diets were progressively used. Soy
content decreased from
26.5% to 13.0%, corn increased from 56.4% to 83.8% and protein
decreased from 18.3%
to 13.3% of the diet (Table 1). Ingredients, including supplements,
were those routinely
used by the piggery and were the same between groups. The GM and
non-GM diets had
the same protein, energy, macro- and micro-nutrient contents and only
differed in the use
of GM or non-GM soy and corn. Pigs were fed on a self-feeding,
full-feed basis. The
amount of feed consumed by each group was recorded.
Table 1. Details of the six body-weight-specific sub-diets used
progressively as pigs grew.
Sub-diet number
1 2 3 4 5 6
Pig weight (lb)a
14-25 25-60 60-90 90-130 130-200 200-260
No. days on dietb
39-40 17-18 23-24 24-25 37-38 15-17
Average daily intake (lb) 0.9 2.43 3.45 4.71 6.10 6.78
Protein (%) 18.6 18.0 17.4 16.3 15.2 14.7
Soy (%)c
26.5 25.0 23.4 20.4 17.5 16.0
Corn (%)d
70.0 71.6 73.2 76.3 79.8 81.3
UN premix (%)e
2.5 2.5 — — — —
UG premix (%)f
— — 2.5 2.5 — —
UF premix (%)g
— — — — 2.5 2.5
Boost premix (%)h
0.0025 0.0025 0.001 0.0015 0.0015 0.0015
Extra lysine — — 0.001 0.0005 — —
Extra CaCO3 (%) 0.0075 0.0075 0.006 0.006 0.002 0.002
200 mesh bentonite clay (%) 0.0035 0.0035 0.0035 0.0035 0.0035 0.0035
Carman, Vlieger, Steeg, Sneller, Robinson, Clinch-Jones, Haynes & Edwards
ISSN 1177-425 41a
As the piggery was in the USA, pig diets were changed when pigs
reached a certain weight in pounds.
b Because pig handlers were required to keep to usual piggery
practices and were blinded as to the GM
feeding status of each group of pigs, pigs in each group were changed
from one sub-diet to the next
according to the body weight of the group. Consequently, one group was
often changed to the next sub-diet a
day before the other group. While the GM-fed group spent one day
longer on a particular diet than the non
GM group for three diets, the non-GM group spent a day longer on a
particular diet for the other three diets.
Therefore, there was neither a trend nor a difference in the
progression of the two groups from one diet to
another. Pigs were fed for a total of 158 days if they were
slaughtered on the first of the two slaughter days,
and 159 days if they were slaughtered on the second slaughter day.
c GM soy went into the GM diets and non-GM soy into the non-GM diets.
d GM corn went into the GM diets and non-GM corn into the non-GM diets.
e Ultra Nursery Plus Premix from Advanced Biological Concepts, Osco,
Illinois, containing (as copied directly
from the label) guaranteed amounts of 0.5% crude protein, 6.0% lysine,
0.5% crude fat, 3.0% crude fiber
13.0% to 15% calcium, 13.0% phosphorus, 16.0% to 18.0% sodium
chloride, 10ppm selenium, 1,500 ppm
zinc, 190,000 IU/lb vitamin A, 25,000 IU/lb vitamin D3 and 800 IU/lb
vitamin E. Other ingredients on the label
(not quantified), include: copper, iron, zinc, manganese, choline,
ascorbic acid, niacin, riboflavin, pantothenic
acid, vitamin K, vitamin B12, carotene and iodine.
f Ultra Grower Premix Plus from Advanced Biological Concepts, Osco,
Illinois, containing (as copied directly
from the label) guaranteed amounts of 0.5% crude protein, 1.0% lysine,
0.5% crude fat, 3.0% crude fiber,
15.0% to 17% calcium, 12.0% phosphorus, 15.0% to 17.0% sodium
chloride, 3ppm selenium, 1,500 ppm
zinc, 160,000 IU/lb vitamin A, 22,000 IU/lb vitamin D3 and 800 IU/lb
vitamin E. Other ingredients on the label
(not quantified) include: copper, iron, zinc, manganese, choline,
niacin, riboflavin, pantothenic acid, vitamin K,
vitamin B12, carotene and iodine.
g Ultra Finisher Premix Plus from Advanced Biological Concepts, Osco,
Illinois, containing (as copied directly
from the label) guaranteed amounts of 0.5% crude protein, 3.0% lysine,
0.5% crude fat, 3.0% crude fiber,
18.0% to 20.0% calcium, 10.0% phosphorus, 6.5% to 7.5% sodium
chloride, 3ppm selenium, 4,000 ppm zinc,
125,000 IU/lb vitamin A, 20,000 IU/lb vitamin D3 and 500 IU/lb vitamin
E. Other ingredients on the label (not
quantified) include: copper, iron, zinc, potassium, magnesium,
manganese, choline, ascorbic acid, niacin,
riboflavin, pantothenic acid, vitamin K, vitamin B12, carotene and iodine.
h Natural Boost from Advanced Biological Concepts, Osco, Illinois,
containing (as copied directly from the label)
guaranteed amounts of 10.0% crude protein, 0.005% lysine, 0.005%
methionine, 1.0% crude fat, 24.0%
crude fiber, 40.0% acid detergent fiber, 0.2% to 0.7% calcium, 0.2%
phosphorus, 1.0% to 1.5% sodium
chloride, 0.5% potassium, 500ppm copper, 1,500 ppm zinc, 180,000 IU/lb
vitamin A, 55,000 IU/lb vitamin D3
and 500 IU/lb vitamin E. Other ingredients on the label (not
quantified) include: iron, zinc, magnesium,
manganese, choline, cobalt, ascorbic acid, niacin, riboflavin,
pyridoxine HCl, pantothenic acid, biotin, vitamin
K, vitamin B12, folic acid, carotene and iodine.
Mycotoxin analyses (Midwest Laboratories Inc, Omaha, Nebraska, US)
showed 2.08 ppb
total aflatoxins and 3.0 ppm total fumonisins in a pooled sample of
the GM feed and no
aflatoxins and 1.2 ppm total fumonisins in a pooled sample of the
non-GM feed. No other
mycotoxins were detected. These levels are well below the USA and EU limits for
mycotoxins in pig feed. In addition, according to common industry
practice, a mycotoxin
binding agent (200 mesh bentonite clay) was added to the diets of
young pigs (Table 1).
Animals
Standard commercial Yorkshire-cross piglets were obtained from a
commercial farrowing
facility as a result of crossing Hampshire Duroc males with Yorkshire
Landrace females.
All sows were fed the same diet containing some GM ingredients and
were impregnated
at a similar time to obtain isowean piglets. Male piglets were
neutered at three days of
age in order to fulfill market requirements for meat free of boar-taint.
Unweaned piglets (N=168; average 24 days of age) were transported to
the piggery
nursery and randomly placed into pens of 14 each. Pens were then
randomly allocated to
receive either a GM or non-GM diet. Animals were weighed and then fed
their allocated
diet as their first solid food. After 32 days, pigs were transported
to a different facility for
the ‘growing and finishing’ phase, where they continued on their
allocated diets but were
housed as 42 pigs per pen with outside access. Throughout, pigs were
housed according
Journal of Organic Systems, 8(1), 2013
42 ISSN 1177-4258to usual industry practices, under shelter on
concrete floors. They experienced the
natural daytime/night-time temperature and light/dark cycle.
Data collected from live pigs
Individual weights were recorded weekly and animals were monitored
daily by observers
who were blinded to a pig's dietary group. Daily measurements included
inside and
outside air temperature, air quality, weather conditions, level of
activity of pigs around the
feeder and the appearance of the feeder itself, the level of activity
of the pigs around the
water and the appearance of the water, details of any pigs found dead,
details of any pigs
that were moved away from, or back to, the ‘home pen’ and the reasons
for this (e.g. they
were being harassed by other pigs), level of contentment (measured as
content, irritable
or aggressive), presence of cough or sneeze, the presence of any skin
problems (e.g.
pale or discoloured skin or the presence of rashes or sores), any eye
problems, and the
consistency of the stools (normal, some loose or runny stools, lots of
loose or runny
stools). Blood was taken from the jugular vein of awake pigs according
to standard
industry methods two days before the first pigs were slaughtered. The
blood was taken
from a random subset of pigs in the following pattern to prevent any
time-related bias:
approx. half the pigs in the non-GM-fed group, approx half the pigs in
GM-fed group, the
remainder of the non-GM-fed group, and the remainder of the GM-fed
group. Blood was
centrifuged and serum was removed and frozen. Blood biochemical analyses were
undertaken by Marshfield Clinic Laboratories, Marshfield, WI, USA, who
were blinded to
all aspects of the study. The laboratory's reference range for awake
three to four month
old Yorkshire cross pigs was used as it was most applicable for this study.
Autopsy procedure
When the pigs were 26 weeks old, they were fasted for 18 hours and
transported to a
large commercial abattoir where they were slaughtered according to the
usual, approved
methods of the abattoir on two consecutive days. On each day,
approximately equal
numbers of GM-fed and non-GM-fed pigs were slaughtered to prevent any temporal
between-group bias. Pigs on each day were killed within a few minutes
of each other. The
internal organs were carefully removed to prevent faecal contamination
and placed in
individual identified buckets with 2 litres of cold phosphate-buffered
saline to quickly chill
the organs. Organs were kept under near-freezing conditions until they
were examined by
two licenced, practicing veterinarians with considerable porcine
experience. They were
blinded as to which pigs were fed GM feed. To remove any
between-inspector bias, one
veterinarian examined all the kidneys, hearts, lungs and stomachs
while the other
examined all the livers, spleens, intestines, uteri and ovaries.
Veterinarian comments and
organ weights were recorded by the same person to remove any between-person
measurement bias or recording bias. Where evisceration resulted in
incomplete removal
of an organ, veterinarians determined if disease had caused part of an
organ to adhere to
the chest or abdominal wall and hence remain with the carcass, as well
as the nature of
that disease. The weights of partial organs were not included in
statistical analyses due to
the errors they would have produced. Kidney weights were the sum of
both kidneys per
pig. Ovary weights were the sum of both ovaries per pig except for two
GM-fed pigs
where one ovary was accidentally removed by the abattoir. Here, the
weight of both
ovaries was estimated by doubling the weight of the remaining ovary.
Intestines could not
be weighed or inspected due to the amount of digesta still present in
them, even after 18
hours of fasting, so the external surface of the intestines was
examined for abnormalities
Carman, Vlieger, Steeg, Sneller, Robinson, Clinch-Jones, Haynes & Edwards
ISSN 1177-425 43and any intramural, palpable tissue masses. Organ
weights were analysed as a
percentage of body weights.
In addition to externally examining the organs, veterinarians also
examined the interior of
every kidney using a single, deep transverse cut, every heart by
slicing into both
ventricles and both atria, and every lung using at least two deep cuts
through the dorsal
surface of each lung lobe, and if abnormalities were found, several
more cuts to properly
identify the abnormality and its extent. Every stomach was examined by
cutting it open
along the length of its greatest curvature, washing out the contents
and inspecting the
entire internal surface of the opened-flat stomach, including rugae.
Data analysis
A stomach erosion was defined as an abnormal stomach surface that had
a visible area
of current inflammation and oedema and where the mucosa was starting
to separate (and
which could potentially progress to form an ulcer). The length of any
ulcer was measured
in millimetres. If an ulcer had a clot in it, or showed frank
bleeding, it was recorded as a
bleeding ulcer. If an ulcer was less than 1 mm in length, it was
recorded as a pin-point
ulcer, otherwise as a frank ulcer. When calculating the total length
of ulceration in each
stomach in mm, each pin-point ulcer was numerically rounded to be 1mm
in length.
Stomach inflammation was scored by the attending, blinded veterinarian
as a result of
expertise obtained from numerous pig autopsies and a classification
system developed
as a result of an earlier, preliminary study on pig stomachs. These
stomachs were
obtained from a random sample of pigs from the same abattoir and came from pigs
raised by other commercial pig producers. Inflammation was classified
as nil, mild,
moderate, or severe based on a combination of the area of current
inflammation and level
of redness and swelling. Typical examples of each of the four
categories of inflammation
are shown in Figure 1. For a severe level of inflammation, almost the
whole fundus had to
be swollen and cherry-red in colour.
Data were analysed using the statistical packages SPSS and EpiInfo.
Continuous data
were analysed by removing SPSS-identified extreme outliers, being
those more than
three times the interquartile range away from the lower or upper
quartiles. This
conservative and well-established approach better tests the nature of
the underlying
distribution. Data were then tested for normal distribution using the
Shapiro-Wilk test. If a
normal distribution was found for both dietary groups, data were
expressed as means
and standard deviations and were analysed using parametric methods
(t-test), otherwise
data were expressed as medians and ranges and analysed using non-parametric
methods (Mann-Whitney U test). Categorical data were analysed using
uncorrected chi
squared tests unless an expected cell value was less than five, when
Fisher's Exact was
used.
Journal of Organic Systems, 8(1), 2013
44 ISSN 1177-4258Figure 1. Different levels of stomach inflammation
found (clockwise from top left):
nil (from a non-GM-fed pig, number B41), mild (from a non-GM-fed pig,
number B15), moderate (from a
GM-fed pig, number C34) and severe (from a GM-fed pig, number D22).
Results
There were no statistically significant differences in food intake,
feed conversion ratios,
number or nature of illnesses, number or nature of veterinary
interventions, veterinary
costs or mortality between the non-GM-fed and GM-fed groups of pigs.
Mortalities were
13% and 14% for the non-GM-fed and GM-fed groups respectively, which are within
expected rates for US commercial piggeries. All dead pigs were
autopsied by blinded
veterinarians and deaths were assessed as due to usual commercial
piggery-related
matters and not to their diets. There was also no difference in body
weights between the
two dietary groups, initially, during, or at the end of the
experiment. Initial weights in kg
were : non-GM-fed group: 6.71 + 1.05 (mean + standard deviation);
GM-fed group: 6.87 +
0.97. Final weights were: non-GM-fed group: 100.42 + 22.84; GM-fed
group: 101.75 +
21.92.
Autopsy results
Organ weights were not statistically different between GM-and
non-GM-fed pigs except
for uterine weights (Table 2). After removing one extreme outlier, the
medians of the non
GM-fed (now N=33) and GM-fed (N=37) groups became 0.084% and 0.105% of the body
weight respectively. That is, the median uterus weight of GM-fed pigs,
as a proportion of
Carman, Vlieger, Steeg, Sneller, Robinson, Clinch-Jones, Haynes & Edwards
ISSN 1177-425 45body weight, was 25% higher than that of non-GM-fed
pigs, which was statistically
significant (p=0.025).
There was no difference in the disease status of organs between the
two groups of pigs
except for the level of inflammation in the stomachs of the pigs
(Table 3, Figure 1). For
non-GM-fed pigs, stomach inflammation was concentrated in the mild and moderate
range, whereas GM-fed pigs showed much more severe inflammation
(p=0.004). GM-fed
pigs showed severe stomach inflammation at a rate of 2.6 times that of
non-GM-fed pigs
(95% confidence interval = 1.29-5.21) (Table 3). This occurred in both
male (p=0.041)
and female (p=0.034) pigs (Table 4). We found severe stomach
inflammation in 22.2% of
male pigs fed the GM diet and in 41.7% of female pigs fed the GM diet
(compared to
5.6% and 18.9%, respectively, in pigs fed the non-GM diet (Table 4).
Blood biochemistry
Blood biochemistry results are given in Table 5. Aspartate transaminase (AST),
potassium and creatine kinase (CK) were not statistically analysed
because they were
raised substantially in both dietary groups due to the way blood was
collected and hence
they were unable to reflect any effect of feeding a GM diet. AST and
potassium were
raised because the collection needle was pushed through muscle, while
CK was raised
due to the pigs being alert and restrained while blood was taken.
While bicarbonate can
increase if pigs pant or squeal unduly during blood taking, no pigs
recorded a bicarbonate
concentration higher than the reference range (Table 6), so this
variable was retained in
analyses.
To determine if feeding the GM diet was associated with a clinically abnormal
biochemistry profile, the proportion of pigs in each dietary group
that lay above (or below)
the reference (normal) range were then compared (Table 6). No
statistically significant
differences were found. The means or medians of the biochemical
variables were also
compared. No significant differences were found (Table 5).
The analyses of several biochemical variables were confounded by the level of
haemolysis in the blood sample. Haemolysis can be a problem when
taking blood from
alert animals, and in non-laboratory settings due to lag times between
sampling and
centrifuging blood. Haemolysis was reported as nil, mild, moderate or
severe by the
laboratory. Total bilirubin, urea nitrogen, creatinine, phosphorus,
calcium, sodium,
chloride, bicarbonate, and anion gap were found to be significantly
correlated with the
level of haemolysis (results not shown) and hence haemolysis was regarded as a
confounder for these variables. Spearman's rho test was used as a
measure of the
association rather than the Pearson correlation co-efficient as it is
less sensitive to
outliers and does not assume normality. These biochemical variables
then underwent
multiple linear regression to control for the effect of haemolysis. As
known confounders
should be controlled-for, even if they do not appear as actual
confounders in initial
studies, glucose also underwent this process. No biochemical variable
was found to have
a significant relationship to the diet with the level of haemolysis
controlled-for (results not
shown). Consequently, no biochemical differences were found between
non-GM-fed and
GM-fed pigs. However, the concentration of GGT, which is a measure of
liver heath, was
16% lower in GM-fed pigs than non-GM-fed pigs and this result was on
the borderline of
statistical significance (Table 5).
Journal of Organic Systems, 8(1), 2013
46 ISSN 1177-4258Table 2. Organ weights (as a percentage of body
weight) - descriptive statistics of raw data
and statistical comparisons of extreme outlier-removed data.
Non-GM-fed GM-fed
Statistical
comparison
of dietary
groups
na
Mean SDb
Median Min Max na
Mean SDb
Median Min Max Test
usedc
pd
Kidneys 66 0.32 0.066 0.31 0.19 0.66 68 0.33 0.057 0.32 0.16 0.56 t 0.51
Heart 69 0.40 0.065 0.40 0.27 0.63 69 0.41 0.059 0.40 0.27 0.61 MW 0.79
Liver 71 1.81 0.342 1.77 1.27 3.20 72 1.79 0.348 1.71 1.25 3.16 MW 0.45
Spleen 73 0.16 0.033 0.16 0.11 0.33 71 0.16 0.032 0.15 0.093 0.30 t 0.40
Lung 67 0.91 0.241 0.87 0.58 2.00 68 0.98 0.315 0.94 0.57 2.52 MW 0.20
Stomach 73 0.62 0.130 0.57 0.42 0.99 71 0.64 0.129 0.60 0.44 1.01 MW 0.26
Uterus 34 0.10 0.048 0.086 0.040 0.31 37 0.12 0.053 0.105 0.036 0.244 MW 0.025*
Ovaries 36 0.0085 0.0027 0.0081 0.0040 0.019 36 0.0086 0.0023 0.0084
0.0047 0.014 t 0.38
a An organ was not included in the analysis if adhesions caused only a
partial organ to remain with the viscera,
due to the errors inclusion would have caused.
b Standard deviation
c After tests for normality, groups were compared by 2-tailed t-test
if data from both dietary groups were
normally distributed, Mann Whitney U test (MW) otherwise.
d* p<0.05 to 0.01, ** p<0.01 to 0.001, *** p<0.001
Table 3. The proportion of pigs in each dietary group with adverse
findings on gross
pathology
Organ Condition
Proportion with condition
Relative
risk of
condition
in GM-fed
pigs
95%
confidence
interval of
the relative
risk
pa
Organ Condition
Non-GM-fed GM-fed Relative
risk of
condition
in GM-fed
pigs
95%
confidence
interval of
the relative
risk
pa
Organ Condition No.
N=73 %
No.
N=72 %
Relative
risk of
condition
in GM-fed
pigs
95%
confidence
interval of
the relative
risk
pa
Kidney Any abnormality 0 0.0 0 0.0 —b
—b
—b
Heart Any abnormalityc
11 15.1 5 6.9 0.46 0.17-1.26 0.119
Liver Any abnormalityd
6 8.2 3 4.2 0.51 0.13-1.95 0.494
Spleen Any abnormalitye
3 4.1 2 2.8 0.68 0.12-3.93 1.000
Lung
Pneumoniaf
42 57.5 43 59.7 1.04 0.79-1.36 0.789
Lung Fibrous pleuritis or pericarditis 9 12.3 4 5.6 0.45 0.15-1.40 0.153 Lung
Abnormal lymph nodesg
13 17.8 16 22.2 1.25 0.65-2.40 0.506
Stomach
Nil inflammation 4 5.4 8 11.1 2.03 0.64-6.44 0.218
Stomach
Mild inflammation 31 42.5 23 31.9 0.75 0.49-1.16 0.190
Stomach
Moderate inflammation 29 39.7 18 25.0 0.63 0.39-1.03 0.058
Stomach
Severe inflammation 9 12.3 23 31.9 2.59 1.29-5.21 0.004**
Stomach
Erosion(s) 63 86.3 58 80.6 0.93 0.81-1.08 0.352
Stomach
Pin-point ulcer(s) 13 17.8 9 12.5 0.70 0.32-1.54 0.373
Stomach
Frank ulcer(s) 15 20.5 17 23.6 1.15 0.62-2.12 0.657
Stomach
Bleeding ulcer(s) 0 0.0 2 2.8 —b
—b
0.245
Intestines Any abnormality 0 0.0 0 0.0 —b
—b
—b
Uterus Filled with fluidh
0
i
0.0 2
j
5.6 —b
—b
0.493
Ovary Any abnormality 0
k
0.0 0
l
0.0 —b
—b
—b
Carman, Vlieger, Steeg, Sneller, Robinson, Clinch-Jones, Haynes & Edwards
ISSN 1177-425 47a Uncorrected chi-square test unless an expected cell
value was less than five, when Fisher exact test (2-tailed)
was used. * p<0.05 to 0.01, ** p<0.01 to 0.001, *** p<0.001
b No statistic could be calculated because one or more cells contained zeros.
c Adhesions and/or fibrous pericarditis and/or scar tissue.
d Adhesions and/or fibrinous tags and/or the presence of fibrin.
e Adhesions and/or fibrinous tags.
f Consolidating bronchopneumonia of the cranial ventral lung lobe(s)
and/or caudal lobe(s).
g Haemorrhagic and/or swollen bronchial lymph node(s).
h When two uteri were removed from neighbouring organs, fluid oozed from them.
i N=36. Of 37 females, one had a congenital defect. It had only the
beginnings of a uterine tract and no uterus or
ovaries.
j N=36.
k N=36. Of 37 females, one had a congenital defect. It had only the
beginnings of a uterine tract and no uterus
or ovaries.
l N=35. Of 36 females, one had a uterus but no ovaries, which were
removed by accident during slaughter and
retained by the slaughterhouse.
Table 4. Stomach inflammation by gender.
Gender Level of
stomach
inflammation
Proportion with condition
Relative
risk of
condition
in GM-fed
pigs
95%
confidence
interval of the
relative risk
Gender Level of pa
stomach
inflammation
Non-GM-fed GM-fed
Relative
risk of
condition
in GM-fed
pigs
95%
confidence
interval of the
relative risk
Gender Level of pa
stomach
inflammation No.b
% No.c
%
Relative
risk of
condition
in GM-fed
pigs
95%
confidence
interval of the
relative risk
pa
Males
Nil 1 2.8 4 11.1 4.00 0.47-34.07 0.357
Malesaes Mild 16 44.4 12 33.3 0.75 0.42-1.35 0.334
Moderate 17 47.2 12 33.3 0.71 0.40-1.26 0.230
Males
Severe 2 5.6 8 22.2 4.00 0.91-17.56 0.041*
Females
Nil 3 8.1 4 11.1 1.37 0.33-5.70 0.711
Females Females Mild 15 40.5 11 30.6 0.75 0.40-1.41 0.373
Moderate 12 32.4 6 16.7 0.51 0.22-1.22 0.118
Females
Severe 7 18.9 15 41.7 2.20 1.02-4.76 0.034*
a Uncorrected chi-square test unless an expected cell value was less
than five, when Fisher exact test (2-tailed)
was used. * p<0.05 to 0.01, ** p<0.01 to 0.001, *** p<0.001
b N=36 for males, N=37 for females.
c N=36 for males, N=36 for females.
Journal of Organic Systems, 8(1), 2013
48 ISSN 1177-4258Table 5. Blood biochemistry descriptive statistics of
raw data and statistical comparisons of
extreme outlier-removed data.
Non-GM-fed GM-fed Reference rangea
Statistical
comparison
of dietary
groups
N Medianb
(Mean)
Rangeb
(SD)
N Medianb
(Mean)
Rangeb
(SD)
Standard
(asleep)c
Awake
(Yorkshire
X)d
Test
usede
pf
Glucose (mg/dL) 39 89.0 58 – 109 38 90.5 52 – 111 85 – 150 58.0 – 197.0 MW 0.81
ASTg
(U/L) 39 60.0 21 – 2757 38 57.0 12 – 1724 32 – 84 0.0 – 45.0 MW 0.72
Total bilirubin (mg/
dL)
39 0.10 0.1 – 0.3 38 0.10 0.1 – 0.3 0.0 – 1.0 0.1 – 0.2 MW 0.76
Cholesterol (mg/dL)39 100.0 56 – 140 38 100.0 55 – 125 36 – 54 50.0 –
92.0 MW 0.85
Total protein (g/dL) 39 (6.48) (0.95) 38 (6.63) (0.91) 7.9 – 8.9 5.1 –
6.9 t 0.16
Albumin (g/dL) 39 4.00 1.7 – 4.7 38 4.10 1.7 – 4.8 1.9 – 3.3 3.0 – 4.4 MW 0.59
Urea nitrogen (mg/
dL)
39 11.0 5 – 22 38 12.0 8 – 29 10 – 30 4.3 – 12.7 MW 0.30
Creatinine (mg/dL) 39 0.90 0 – 1 38 0.70 0 – 1 1.0 – 2.7 0.9 – 1.9 MW 0.21
Phosphorus (mg/
dL)
39 (9.1) (1.5) 38 (9.1) (1.5) 5.3 – 9.6 6.2 – 9.2 t 0.99
Calcium (mg/dL) 39 10.70 5.5 – 11.3 38 10.50 5.1 –12.0 7.1 –11.6 9.1 –
10.8 MW 0.94
Sodium (mmol/L) 37 140.0 98 – 148 37 140.0 98 – 145 135 - 150
132.0–144.0 MW 0.60
Potassium (mmol/
L)
38 6.35 4.6 – 13.9 37 6.40 4.3 –16.3 4.4 – 6.7 3.4 – 5.0 MW 0.56
Chloride (mmol/L) 38 97.0 67 – 104 37 98.0 66 – 102 94 – 106 94.0 –
103.0 MW 0.86
Bicarbonate (mmol/
L)
39 33.0 19 – 37 38 33.5 18 – 37 18 – 27 28.0 – 37.0 MW 0.44
CKh
(U/L) 39 2416.0 214 –22500 38 1960.0 10 –22500 61 –1251264.0–1247.0 MW 0.73
GGTi
(U/L) 39 (35.1) (18.4) 38 (29.5) (18.1) 10 – 60 0.0 – 60.0 t 0.05
Anion gap (mmol/
L)j
37 16.0 12 – 23 37 15.0 11 – 27 – – MW 0.61
a From Marshfield Clinic, Marshfield, WI, USA.
b Medians and ranges are reported for non-parametric comparisons,
means and standard deviations for
parametric comparisons.
c Marshfield Clinic's usual reference range. Pigs were anaesthetised
to obtain blood.
d Marshfiled Clinic's reference range for awake, 3-4 month-old
Yorkshire cross pigs. This was used as it is much
more applicable to this study.
e After tests for normality, groups were compared by two-tailed t-test
if data from both dietary groups were
normally distributed, Mann Whitney U test (MW) otherwise.
f * p<0.05 to 0.01, ** p<0.01 to 0.001, *** p<0.001
g Aspartate transaminase.
h Creatine kinase.
i Gamma-glutamyl transferase.
j There is no laboratory reference range for anion gap. Sorbitol
dehydrogenase results were not given by the lab
on this occasion.
Carman, Vlieger, Steeg, Sneller, Robinson, Clinch-Jones, Haynes & Edwards
ISSN 1177-425 49Table 6. Biochemical variables compared to the reference rangea
to determine clinical
significance.
Biochemical
variable
Number (%) above or below reference range
Biochemical
variable
Non-GM-fed (N=39) GM-fed (N=38)
Biochemical
variable Above
reference
range
Below
reference
range
Above
reference
range
Below
reference
range
Glucose 0 (0) 0 (0) 0 (0) 2 (5)
ASTb 23 (59) —c
24 (63) —c
Total bilirubin 1(3) 0 (0) 1 (3) 0 (0)
Cholesterol 29 (74) 0 (0) 28 (74) 0 (0)
Total protein 10 (26) 4 (10) 17 (45) 3 (8)
Albumin 7 (18) 5 (13) 3 (8) 5 (13)
Urea nitrogen 10 (26) 0 (0) 16 (42) 0 (0)
Creatine 0 (0) 18 (46) 0 (0) 23 (61)
Phosphorus 12 (31) 2 (5) 16 (42) 1 (3)
Calcium 10 (26) 9 (23) 14 (37) 6 (16)
Sodium 2 (5)d
4 (11)d
0 (0)d
4 (11)d
Potassium 34 (89)e
0 (0)e
36 (97)d
0 (0)d
Chloride 1 (3)e
7 (18)e
0 (0)d
4 (11)d
Bicarbonate 0 (0) 5 (13) 0 (0) 5 (13)
CKf
24 (62) 2 (5) 27 (71) 1 (3)
GGTg 2 (5) —c
1 (3) —c
a Awake Yorkshire cross pig reference range from Marshfield Clinic,
Marshfield, WI, USA. Anion gap has no
reference range so was not included in the table.
b Aspartate transaminase.
c It was not possible for a pig to record a concentration below the
bottom of the reference range, which was
zero.
d N=37.
e N=38.
f Creatine kinase.
g Gamma-glutamyl transferase.
Discussion
In this study, we found that female pigs fed the GM diet had median
uterine weights that
were 25% greater than non-GM-fed pigs (p=0.025). This result is
attributed to the
difference in diet as other variables were controlled for, including
the presence of
mycotoxins, and possible confounders such as infectious diseases,
animal husbandry
considerations and various forms of bias such as temporal, between-person,
measurement or recording bias, as these were all controlled-for. The
concentration of
mycotoxins in the feed was insignificant, both dietary groups received
the same nutrients
and care, the care complied with industry standards, and all those
doing laboratory
analyses and weighing, caring for, slaughtering and doing autopsies on
pigs were blinded
as to the dietary group of each pig.
Journal of Organic Systems, 8(1), 2013
50 ISSN 1177-4258The reported difference in uterine weight warrants
further investigation in future studies
because such a biologically significant difference in uterine weights
may reflect
endometrial hyperplasia or carcinoma, endometritis, endometriosis, adenomyosis,
inflammation, a thickening of the myometrium, or the presence of
polyps. The uteri from
two GM-fed pigs were full of fluid compared to nil from non-GM-fed
pigs (Table 3) which
may be linked to pathology. The link between an increase in uterine
weights and GM
feeding is supported by other authors (Brasil et al., 2009) who found
that GM soy-fed rats
had a statistically significant 59% increase in the density of the
uterine endometrial
glandular epithelium compared to rats fed an equivalent organic soy
diet. Further studies
should include histology, blood oestrogen, progesterone and cytokine
concentrations, and
which GM crop(s) and their GM protein products may, or may not, be
involved. As this
study used neutered males, further studies are required to investigate
any potential effect
of these crops on male reproduction. Multigenerational reproductive
studies should also
be considered.
In this study, a diet of GM feed had no effect on stomach erosions or
ulceration but had a
significant effect on inflammation. Pigs fed the mixed GM soy and GM
corn diet showed
2.6 times the rate of severe stomach inflammation compared to non-GM
fed pigs. This
biologically significant finding was statistically significant
(p=0.004). GM-fed male pigs
showed severe stomach inflammation at a rate of 4.0 times that of the
non GM fed male
pigs (p=0.041); and female pigs showed a rate of severe stomach
inflammation that was
2.2 the rate of the non-GM fed female pigs (p=0.034).
The pig industry uses finely-ground feed to maximise feed efficiency
which can increase
inflammation and ulceration of the stomach (Wolf, 2010). We therefore
controlled the
grind size, removing it as a confounder. Hence our results show that
these GM crops
were associated with stomach inflammation that was additional to any
that may be
caused by particle size. The result is attributed to the difference in
diet, since the
presence of mycotoxins, possible confounders such as infectious
diseases, animal
husbandry considerations or temporal, between-person, measurement and
recording bias
were controlled across the two groups.
One explanation for the inflammation results could lie with the Cry
3Bb1 and Cry 1Ab
proteins that these GM corn varieties are engineered to produce. They
act as insecticides
by inducing pore formation and disintegration of the gut tissue (Spok
et al., 2007) of
certain grubs that attack corn plants. It has been argued that these
proteins cannot harm
the gastrointestinal tract of mammals because mammals lack the necessary gut
environment and receptors (ANZFA, 2000). However, Vazquez-Padron et
al. (2000) found
six proteins in the mouse small intestine that could bind to a Cry
protein (Cry 1Ac).
Furthermore, when the Cry protein bound to these proteins, it resulted in
hyperpolarisation of the intestine, which is consistent with the
formation of cationic
channels, as occurs in the insect gut (Vazquez-Padron et al., 2000).
In addition, an
independent in vivo study found structural changes and hyperplasia in
the ileum of mice
fed a Cry protein for two weeks (Fares & El-Sayed, 1998). Chowdhury et
al. (2003) and
Walsh et al. (2012b) found the Cry1Ab protein (which was present in
the feed in our
study) throughout the digestive tract of pigs. Chowdhury et al. (2003)
found the protein
(and sections of the gene that codes for it) in the stomach, duodenum,
ileum, caecum
and rectum of pigs fed Bt11 corn for four weeks, while Walsh et al.
(2012b) found the
protein in the stomach, caecum and colon of pigs fed MON810 corn for
110 days (they
Carman, Vlieger, Steeg, Sneller, Robinson, Clinch-Jones, Haynes & Edwards
ISSN 1177-425 51appear not to have looked in the rectum), indicating
that this protein is resistant to
digestion in pigs. In our study, stomach inflammation may be due to
one or both of the
Cry proteins fed in the study and future studies may provide answers.
The findings in this study are conservative since the non-GM diet pigs
were exposed,
albeit minimally, to potential GMO impacts. The presence of small amounts of GM
material in the non-GM feed, using out-bred animals, piglets from
GM-fed sows, and
performing the study in a commercial setting (including the potential
exposure of the pigs
to any infectious diseases common to US commercial pigs and taking
blood on site)
could be expected to reduce any differences between the two dietary groups.
We found that our key findings were not reflected in the standard
biochemical tests often
undertaken by researchers in this area, probably because such tests
provide a poor
measure of inflammation and matters associated with uterine size. We
suggest that the
following may be better measures: the red blood cell count and
haematocrit to measure
anaemia and iron deficiency from possible blood loss, C-reactive
protein and white blood
cell count to measure inflammation, and oestrogen and progesterone.
In addition, if an autopsy is done at the end of a GM crop feeding
experiment, this often
involves only a visual inspection of the exterior of organs without
weighing them.
However by weighing organs we found a significant 25% increase in
uterine weights in
the GM-fed pigs. Moreover, where organs are weighed in such studies,
they are often not
examined internally (Carman, 2004) and such an approach would preclude
finding the
stomach inflammation reported in the present study.
The present study is an observational study of the action of a mixture
of GM crops on the
health of pigs, versus a comparable non-GM diet. Future work will
investigate individual
GM crops, will involve histopathology, and will consider mechanisms
for reported group
differences.
Conclusion
Pigs fed a GMO diet exhibited heavier uteri and a higher rate of severe stomach
inflammation than pigs fed a comparable non-GMO diet. Given the
widespread use of
GMO feed for livestock as well as humans this is a cause for concern.
The results
indicate that it would be prudent for GM crops that are destined for
human food and
animal feed, including stacked GM crops, to undergo long-term animal
feeding studies
preferably before commercial planting, particularly for toxicological
and reproductive
effects. Humans have a similar gastrointestinal tract to pigs, and
these GM crops are
widely consumed by people, particularly in the USA, so it would be be
prudent to
determine if the findings of this study are applicable to humans.
Conflict of Interest Statement
The authors declare that there are no conflicts of interest.
Acknowledgments
This research was funded by the Institute of Health and Environmental
Research (IHER) and Verity
Farms. Funding for IHER's involvement came from the Government of
Western Australia (WA) and
George Kailis. Funding for Verity Farm's involvement came from Verity
Farms. We gratefully
Journal of Organic Systems, 8(1), 2013
52 ISSN 1177-4258acknowledge the following people for their assistance
(alphabetical order): Elaine Attwood, Susan
Bardocz, Ed Boote, Kim Chance, Nick Costa, John Coveney, Philip
Davies, Colton Eckmann,
Peggy Eckmann, Rick Eckmann, John Fagan, Leanne Good, Gene Haverdink,
Ryan Hawkins, Jack
Heinemann, George Kailis, Britney Kaufman, Kiley Kaufman, Ron Kaufman,
Stephanie Kaufman,
David Kiel, Michelle Koonce, Ed McGuire, Mike McMullan, Julie Newman,
Arpad Pusztai, Patrick
Quinn, Wayne Searcy, Brian Setchell, SiouxPreme Packing Co., Jeffrey
Smith, Duane Spader,
Rosemary Stanton, David Vlieger, Pamela Vlieger, Rachael Vlieger, John
Ymker, Irena Zdziarski.
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54 ISSN 1177-4258
Nathan McCorkle
Jun 12, 2013, 6:18:00 PM6/12/13
to diybio
A few items that pop-up on my 'radar':
26 weeks (158 or 159 days of feeding depending on the slaughter day)
seems short, but says that's the standard piglet to slaughter time...
so, why don't I own a composter that makes bacon for me?
The sample size appears to change from start to results, but it's due
to mortality rate and sex differenes. Started with N=168, of 24 day
old piglets, but then the N==33 and 37 for the organ weight tests.
Mortality was similar, 13% and 14%, so avg 13.5% 168-(168*0.135) =
145.32 pigs alive at the end of the study. Assuming splitting in half
(GM, non-GM eaters) that's 72 subjects each, then splitting again by
sex (it says equal numbers present in each group) that's 36 subjects
I really wish they would have used Bt and Roundup-ready as separate
GMO groups, I'd really like to see more data on pesticide-residue, so
separating the modded feeds would help. I doubt anyone grows unsprayed
(pesticide/insecticide-virgin) roundup-ready corn in significant
quantities to support a study.
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-Nathan
26 weeks (158 or 159 days of feeding depending on the slaughter day)
seems short, but says that's the standard piglet to slaughter time...
so, why don't I own a composter that makes bacon for me?
The sample size appears to change from start to results, but it's due
to mortality rate and sex differenes. Started with N=168, of 24 day
old piglets, but then the N==33 and 37 for the organ weight tests.
Mortality was similar, 13% and 14%, so avg 13.5% 168-(168*0.135) =
145.32 pigs alive at the end of the study. Assuming splitting in half
(GM, non-GM eaters) that's 72 subjects each, then splitting again by
sex (it says equal numbers present in each group) that's 36 subjects
I really wish they would have used Bt and Roundup-ready as separate
GMO groups, I'd really like to see more data on pesticide-residue, so
separating the modded feeds would help. I doubt anyone grows unsprayed
(pesticide/insecticide-virgin) roundup-ready corn in significant
quantities to support a study.
> -- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diy...@googlegroups.com. To unsubscribe from this group, send email to diybio+un...@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
> Learn more at www.diybio.org
> ---
> You received this message because you are subscribed to the Google Groups "DIYbio" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to diybio+un...@googlegroups.com.
> To post to this group, send email to diy...@googlegroups.com.
> Visit this group at http://groups.google.com/group/diybio?hl=en.
> To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/CAGjqrSiUkBH5qnCmG0VHomnoZnAytE74RTZjw_Tyb52SAewgnQ%40mail.gmail.com?hl=en.
> For more options, visit https://groups.google.com/groups/opt_out.
>
>
--
-Nathan
Cathal Garvey (Android)
Jun 13, 2013, 3:08:19 AM6/13/13
to diy...@googlegroups.com
A good breakdown:
http://www.marklynas.org/2013/06/gmo-pigs-study-more-junk-science/
TL;DR:
1) Paper basically self-published in fake journal.
2) Massive ties to individuals and industry bodies that profit from GM scaremongering, so authers have intense competing interests.
3) Same kind of statistical fishing as the Seralini rat trial: induce sickness in all animals through mistreatment, mess with data to blame GMO feed.
4) Evidence of animal cruelty, seems to be a hallmark of antiGMO "studies" these days.
http://www.marklynas.org/2013/06/gmo-pigs-study-more-junk-science/
TL;DR:
1) Paper basically self-published in fake journal.
2) Massive ties to individuals and industry bodies that profit from GM scaremongering, so authers have intense competing interests.
3) Same kind of statistical fishing as the Seralini rat trial: induce sickness in all animals through mistreatment, mess with data to blame GMO feed.
4) Evidence of animal cruelty, seems to be a hallmark of antiGMO "studies" these days.
--
Sent from my Android phone with K-9 Mail. Please excuse my brevity.
Sent from my Android phone with K-9 Mail. Please excuse my brevity.
Mega
Jun 13, 2013, 5:11:56 AM6/13/13
to diy...@googlegroups.com
They didn't make a difference between the genes inserted, right.
One GMO which was inserted a gene that codes for a toxin will be a risk for human consumption (although there are also poisonous fungi in nature - just don't eat them and you'll be ok) while another one like Golden Rice will be perfectly dafe to eat and healthy.
Jeswin
Jun 13, 2013, 9:00:03 AM6/13/13
to diy...@googlegroups.com
On Thu, Jun 13, 2013 at 3:08 AM, Cathal Garvey (Android)
<cathal...@cathalgarvey.me> wrote:
> A good breakdown:
> http://www.marklynas.org/2013/06/gmo-pigs-study-more-junk-science/
>
> TL;DR:
> 1) Paper basically self-published in fake journal.
Yea, probably right on this. I couldn't find it listed on the SCImago
<cathal...@cathalgarvey.me> wrote:
> A good breakdown:
> http://www.marklynas.org/2013/06/gmo-pigs-study-more-junk-science/
>
> TL;DR:
> 1) Paper basically self-published in fake journal.
Journal ranking site.
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