Use of bovine somatotropin at the time of surgery for left displacement of the abomasum in dairy cows

Objective - To evaluate the effect of a single dose of recombinant bovine somatotropin (bST) on certain metabolic values, health, and milk production of dairy cows undergoing surgery for left displacement of the abomasum. Design - Blinded clinical trial. Animals - 413 cows with left displacement of the abomasum. Procedure - A single 500-mg dose of bST was administered to dairy cows following surgery in field practice conditions for left displacement of the abomasum. A placebo of the same carrier without bST was administered to control cows in this blinded study. Metabolic and production responses in a short-term follow-up period were measured. Results - Blood glucose concentrations in cows 3 to 5 days after surgery were statistically higher for treated cows than for control cows. A higher proportion of treated cows had improved urine ketone test results than did controls. Significant differences in other metabolic values, health, and milk production were not detected. Clinical Implications - Treatment of metabolically compromised cows with bST may have some positive effects, but further investigation is needed to confirm therapeutic value.