What is the right milking interval?

[Juergen Steen]

Dear Kendra,

I would like to come back to one of your earlier e-mails:

Quote
One cow milking twice a day
could have intervals sitting around 12 hours whilst another cow could
have intervals more in the order of 6 and 18 hours (depending on her
routine) which could reduce milk production compared to a more
consistent interval.
Quote end

It is a well known fact that the rate in which the cow produces the milk
after the milking has a peak shortly after the milking with a peak around
4-6 h after the milking. Later the milk production reduces while physical
pressure and osmotical pressure in the udder increase. 3x milking systems
try to harness the peak production levels while anecdotal evidence from OAD
suggests that the negative impact of a long interval is very limited
especially if you correct milk production by components.

Is there data out of the research in Camden that can quantify this effect a
bit more? At what interval has the cow the highest milksolids/ hour? This
would answer the question about the ideal milking frequency from a per cow
milk production point of view. With milking robots we have the ability to
design milking intervals, a new herd management tool because we are not
restricted to rigid milking times to suit the milker any more.

Next question after that is what is the right balance between the right
milking frequency and maximising the system performance...........

best regards,

Jurgen Steen
Manager Dairy Equipment South West Pacific
Lely Australia PTY LTD
48 Mackay Street, Rochester
3561 Victoria, Australia
Phone: +61 354 844000
Fax: +61 354 841 513
Mobile: +61 417 102 303
jst...@lely.com
www.lely.com

[Kendra Davis]

What is the right milking interval - unfortunately I do not believe
there is a right answer to this question. I think this is highly
dependent on the genetics of the herd and the individual cow and even
more so on the system/feeding type in question and the production level
of the cows.

I think the timing of the peak milk production after a given milking
session is dependent on the rate of milk production. You mention 3x
daily milking and once-a-day (OAD) milking systems. Even in NZ with
lower producing cows and lower input systems there are some cows that
are particularly suited to OAD and cows that really are not suited. If
you were to take OAD into a much higher producing herd, the impacts
would be much greater with production per cow being considerably reduced
- and surely less of this would be compensated by higher milk solids %.

My point was that with two cows milking twice-a-day, one could be
milking at roughly twelve hour intervals whilst the other could be
milking with a combination of very long and very short intervals. Some
work that we did last year specifically on this topic showed a
significant production advantage (at least in the short term) for cows
to held at reasonably consistent milking intervals. With irregular
milking intervals it was the long intervals that caused the reduced
production rate. Intervals exceeding about 14-15 hours were resulting
in reduced milk production levels for the majority of the cows and also
was having an effect on the absolute yield of components.

Across the trial we found that cows milked at a regular milking interval
(10-14 hours) produced an additional 1.5 litres of milk, 0.09 kg fat and
0.06 kg protein per day over the cows that were milked at irregular
intervals. This was in a controlled trial whereby we actually fetched
the cows to ensure that they were milked at predetermined intervals and
all at milking frequencies of twice-a-day.

However, in the same trial it was also noted that at least in the
short-term there were some cows that coped with milking intervals
ranging from 4 hours to 20 hours with absolutely no indication that
their milk yield (or the components) was affected by the longer
intervals. Perhaps we need a herd of these cows, milked at intervals of
20 hours allowing us to milk 125 cows per milking station with an
average milking frequency of 1.2 milkings per cow per day!!

So I guess from the work we have carried out so far I would suggest that
minimising the number of milkings exceeding about 14 hours is beneficial
capturing intervals as low as 4-5 hours was not particularly beneficial
unless the capacity of the system allows for cows to be milked a those
lower intervals. Minimising the variation in milking interval should be
a focus.

If any of this is not clear or creates confusion please feel free to
respond.

Kind Regards

Kendra