PREVENTION AND MONITORING OF DISPLACED ABOMASUM IN DAIRY-CATTLE

Studies on prevention and monitoring of displaced abomasum in daily ca ttle are reported. The degree of heritability of displaced abomasum in German Black Holsteins was estimated with 24%, indicating that displa ced abomasum incidence might be lowered by gen etic selection. Asparta te-aminotransferase activity in blood, beta-hydroxybutyrate concentrat ion in blood and milk, and the fat protein ratio (FPR) in milk are fre quently increased one to three weeks prior to displaced abomasum diagn osis, AST greater than or equal to 100 Un blood BHB > 1000 mu mol/l bl ood, Ketolac(R) BHB indicating greater than or equal to 100 mu mol BHB /l milk, and FPR greater than or equal to 1.4 might be used to monitor for subsequent displaced abomasum, however low sensitivity and specif icity gave few: true positive results and many false positive results. Under certain conditions (high displaced abomasum incidence, low test costs, availability of means to prevent displaced abomasum in cows at increased risk) the use of these tests for monitoring might be cost e ffective. Subclinical ketosis is a risk factor of displaced abomasum i n dairy cows.