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. ©