Effect of the Use of Bovine Somatotropin on Culling Practices in Thirty-two Dairy Herds in Indiana, Michigan, and Ohio

¹ Monsanto Dairy Business, 2692 Blue Haven Ct., East Lansing, MI 48823
² Monsanto Dairy Business, 800 N. Lindbergh Blvd., St. Louis, MO 63167

Data from 5468 Holstein dairy cows in 32 herds were used to determine the effect of the use of bovine somatotropin (bST) on culling practices over a 13-mo period. After an initial herd inventory, monthly information regarding cow entry and exit from the herds was obtained by seven participating veterinarians. Culling was coded by farmers for the following reasons: low production, reproduction, somatic cell count, mastitis, sickness, dairy purposes, lameness, death, and other. In the control herds, cows were not treated with bST during the trial. Adopter herds were defined as herds that utilized supplemental bST for 25% of the cow-days during the trial. Mean herd use of bST in adopter herds was 38.6%. No difference in the number of cows culled per cow-day at risk was detected between control and adopter herds (0.09 and 0.11%, respectively). Amount of in-herd use of bST was unrelated to culling. No significant differences were determined between adopter and control herds in the percentage of cows that were culled for any of the nine possible culling reasons. The results of this study suggest that culling patterns in herds that use bST are unaffected for at least the first year after adoption.

Key Words: culling • bovine somatotropin • dairy cow

Submitted on June 5, 1997
Accepted on January 12, 1998

This article has been cited by other articles:

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