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COW MANAGEMENT
WINTER 2011 ISSUE
LIVESTOCK MATTERS
14
MAXIMISE RUMEN FUNCTION
Figures 1a, 1b and 1c are an estimation
of the rumen size of many cows at calving
and then four weeks and ten weeks
post-calving. With appropriate feed
management of the pre-calving cow it is
possible to create a rumen size shown in
1b at calving; such a cow will obviously
have a far greater DMI than 1a. A 1a
cow has a greater disadvantage; not being
able to eat enough and thus is more likely
to suffer from a greater negative energy
balance (NEB). Whenever discussing
diets for the dry and fresh cow it is vital
to reduce competition at the feed face;
I would suggest a minimum of 3 feet/cow
and the feed needs to be fresh, and
available 24 hrs/day.
Calving is routinely the most stressful time of a
cow or heifer's life (see Figure 2). Around this
time there are tremendous hormonal and
metabolic changes. One consequence of this
is that the cow's/heifer's immunological
system is suppressed making her more
susceptible to disease. A complicating factor
to this increased susceptibility is that the
modern Holstein cow has a reduced innate
immunity compared with a cross-bred animal.
Added stressors such as inappropriate
nutrition of the transition cow will undoubtedly
increase the susceptibility to infections such as
mastitis, metritis and endometritis. Work in
North America has shown that diseases will
have a negative effect on the lactation yield
(see Table 1.)
It is difficult to compare herds simply by
recording disease incidence, as the more
examinations/investigations that are
performed, the more disease will be
diagnosed. Provided the same protocols
are carried out, it is possible to compare
farms, and year to year variations. Metritis
and endometritis can ‘only’ be confirmed
by a vaginal examination; it is vital they
are diagnosed early and treated promptly.
Metritis may have a lesser effect on milk
production compared with Left Displaced
Abomasums (LDA's) but the influence on
future fertility can be dramatic, increasing
the chances of being culled as barreners.
One farm has installed a 'S C R H R
system' which records both activity and
rumination time of individual animals. It has
been noticed, from observing the rumination
time, that fresh calvers, which are
developing a problem, 'cope' for the first
four days post-calving and then suddenly
reach a 'breaking point', when the
rumination time reduces to half, compared
with the previous four days. Examination
of these cows reveals some have an
elevated temperature and many have
a foetid metritis.
Careful observation of individuals in the
fresh group, including milk yields, followed
by clinical examinations of 'suspect' cows
will provide early diagnosis of problems;
rectal temperature is only a guide to a
cow's health.
The use of 3rd and 4th generation
cephalosporins in veterinary practice has
received much comment and their future use
may well be restricted. We have a metritis
problem on one farm where we believe the
feeding of the transition cow is satisfactory
and our protocol for the future is to use
antibiotic uterine pessaries (Bovocycline)
for all assisted calving and retained
foetal membranes.
If we endeavour to maximise rumen
function, reduce stress, treat cows as
individuals, examine if we have any
suspicions and treat promptly, always
looking after the cow, the cow will then
look after us.
Figure 1a: An estimation of rumen size
at calving
Figure 1b: An estimation of rumen size at
4 weeks post-calving
Figure 2: Calving is the most stressful time
in a cow's production cycle
Figure 1c: An estimation of rumen size at
10 weeks post-calving
Table 1:
The effect of disease on
lactation yield
Disease
Loss in yield*
Metritis
250 kg milk
Ketosis
1,100 kg milk
Left displaced
abomasum (LDA)
1,700 kg milk
*These are average figures and delayed treatments can
greatly increase the loss of yield