KLIM
 |  موضوع: Repeat Breeding Syndrome  5/5/2011, 05:31 | |
| Repeat Breeding Syndrome
Copyright © NADIS 2002 - 2007 Reduced fertility is one of the commonest
reasons for vets being called onto dairy farms. In many cases cows
presented to vets have obvious problems such as “whites” or ovarian
cysts. However, not every cow failing to hold to service has an obvious
problem. A significant number (around 10 to 15%) of cows require four or
more inseminations to get pregnant despite apparently cycling normally.
Most of these are indeed “normal” since, assuming no cows are culled
after earlier services, then even in a herd with every cow becoming
pregnant at a rate of 50% (a good rate for our dairy farms these days)
there will be 12.5% of cows presented for a 4th service!
However, in some cases there is an underlying problem reducing the
chance of the cow getting pregnant. These may be either cow factors that
require ultrasound examination or even other more sophisticated tests
e.g. oviduct patency, or the result of a wide range of external factors,
such as poor management. An obvious example is inefficient oestrous
detection. On farm, without extensive testing, it is very difficult to
distinguish between all these factors, as their only sign is a cow that
is apparently normal but hasn’t got pregnant. Such cows get lumped
together as having ‘repeat breeding syndrome’.
Recognising a repeat breeder cow
To identify repeat breeder cows you need two things: good records and
good heat detection. Given what has been said above and that on many
farms the efficiency of oestrous detection is less than 60% (i.e. for
every 10 cows potentially cycling only 6 are served) it can be seen that
this is quite a need! However if done well they allow the farmer or
herdsperson to pick up cows that are cycling normally but not getting
pregnant or most importantly those not fitting a normal pattern. Using
this information these possible problem animals can be identified
quickly, subjected to veterinary examination and a treatment protocol
applied. This reduces the potential days open and so saves money. The
exact amount depends on farm circumstances but it more than pays for a
regular veterinary visit on most farms.
Good records have two values. First and foremost they need to be
referred to easily and quickly. A notebook or breeding calendar is often
better than a computer as a means of reference or “action list”, as it
is usually nearer to the cows. The second use is to exploit these
records to review the herd performance at least annually. Often the
notebook is less useful and even calendars etc., do not lend themselves
to this. It is here that the computer is king. A simple spreadsheet can
do a lot! Most farms have a computer even if it is the children that use
it!
Good heat detection needs an ability to recognise the signs of heat and
time set aside to look carefully for these as in some cases they may not
be very obvious. The 3-week calendar can be very useful in pinpointing
likely candidates. Other aids, such as beacons, tail paint pedometers
and milk progesterones can also improve heat detection but there is
still no really cost effective substitute for the astute observer apart
from the bull. Even the latter can be overwhelmed if there are too many
cows in season at one time.
Treating repeat breeder cowsIf regular veterinary fertility
visits are not used then cows that have had three services and are not
pregnant should be checked before serving again. Many studies have shown
that the treatment of repeat breeder cows, even those that are
apparently normal, does save money. They also show that it is those
farms with good records and good breeding plans that save the most as
they use the veterinary input most efficiently. The management and
treatment of repeat breeders should form a significant part of the
fertility section of your herd health plan.
Preventing repeat breeder cows
1. Ensure you are serving cows at the correct time. This means that
all staff should know the signs of heat. Milk progesterone testing is
also useful; cows in a true heat will have very low progesterone.
2. Ensure insemination techniques are as good as possible. This is
particularly important if you use DIY AI. Do not serve cows previously
diagnosed as pregnant without doing a cow-side progesterone test to
confirm it is has a low progesterone and is not pregnant. If the cow is
pregnant AI may cause foetal loss.
3. Identify and treat cows with whites before starting to serve them.
4. Don’t start serving too soon after calving. Herds that start early
have lower pregnancy rates to service and so more repeat breeder cows.
5. Minimise stress at service. For example, try and avoid serving around turnout or when you change the diet.
A comprehensive analysis and review of your breeding programme is time
well spent in the battle to reduce repeat breeding. Get together with
your vet and go through your herd records and present breeding protocols
and see if there are not some areas where this important area could be
improved | |
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theredrose
| | موضوع: رد: Repeat Breeding Syndrome 5/5/2011, 16:06 | |
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KLIM
| | موضوع: رد: Repeat Breeding Syndrome 16/5/2011, 06:26 | |
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