Factors Associated With Displaced Abomasum
Dr. Allen
Young
USU Extension Dairy Specialist
Displaced abomasum (DA),
principally left displaced, is a disorder of post-partum cows. The incidence
rate appears to be rising and has been listed in two different studies as 3% (0
– 14% of dairies) or 5% (0 – 22% of dairies). Economically, it can cost $100 -
$200 for the actual incident plus about 770 lb milk less for the month after the
problem. In addition, about 10% of cows diagnosed with DA’s will be culled or
die before the next test day. I see a lot of farms with this problem and would
like to list some factors that contribute to DA’s. For further information on
this subject, I would refer you to the articles cited below.
1. Dry cows
that are overconditioned (fat). During the transition period, cows can be in a
negative energy balance. Intakes are usually low, requiring that the cow provide
energy through fat mobilization. If too much fat is mobilized it can be
deposited in the liver, leading to fatty livers and impaired function. In
addition, this can lead to suppressed appetite. This compounds the problem. The
most visible factor associated with this is cows that are too fat, especially
during the dry period. Cows with a body condition score of 4.0 or greater are at
a huge risk! They have a decreased postpartum appetite, mobilize more body fat
and are at a greater risk for ketosis and other metabolic problems.
Beta-hydroxybutyrate (BHBA) can be elevated for at least 9 – 10 days prior to a
DA and nonesterified fatty acids can be elevated one day prior to the DA.
2. Decreased dry matter intake and milk production beginning 3 – 4 days
prior to the DA. These are consequences rather than causes, but can still give
you a hint that a problem is coming. Blood insulin levels can be elevated for at
least 9 – 10 days prior to the DA.
3. Postpartum disorders such as
ketosis, retained placenta, metritis, or milk fever have been shown to increase
the risk of having a DA. Conversely, a cow that has had a DA is at increased
risk of developing one of these disorders. Prevention of postpartum disorders
can decrease the risk of a DA.
4. Lead feeding. This is an interesting
risk factor because we strongly advocate lead feeding of dairy cows; however,
too much concentrate prepartum or not enough can be a contributing factor to
developing a DA. A rule of thumb that appears to walk the line successfully is
to feed around 0.5% of body weight (with an upper limit of 0.75% of body weight)
as prepartum concentrate.
5. Postpartum feeding. Don’t feed more than
60% of the ration as concentrate and feed so that cows cannot sort feed. Keep
fiber levels up by watching the amount of forage in the ration and pay
particularly close attention to the physical form of the feed such as
overmixing, pelleting, etc.
6. Hypocalcemia or low blood levels of
calcium. There has been some research that suggests that hypocalcemia at
parturition can increase the risk of a DA and other research that shows no
relationship. I think that given the interrelatedness of these disorders,
prevention of hypocalcemia is warranted.
As you can see, there are many
interrelated factors to consider when working to prevent DAs. It is very clear
that how you handle your dry cows is extremely important in preventing this
problem. If you are experiencing increased incidence rates of DA’s, a discussion
with your nutritionist and veterinarian is a must. Economically, you can’t
afford to have this problem on your dairy.
Sources:
Shaver, R.D.
1997. Nutritional risk factors in the etiology of left displaced abomasums in
dairy cows: a review. J. Dairy Sci. 80(10): 2449-2453.
Van Winden,
S.C.L., R. Jorritsma, K.E. Muller and J.P.T.M. Noordhuizen. 2003. Feed intake,
milk yield, and metabolic parameters prior to left displaced abomasums in dairy
cows. J. Dairy Sci. 86(4): 1465-1471.