Effects of castration age and diethylstilbestrol on weight gains in male calves
S. W. Thurber, University of California
J. R. Dunbar
D. P. Smith
California Agriculture 20(10):12-14. DOI: 10.3733/ca.v020n10p12.
Sam Thurber is Farm Advisor, Agricultural Extension Service, University of California, Shasta-Lassen county office; John Dunbar is Farm Advisor, Humboldt County; Dean Smith is Farm Advisor, Inyo-Mono county office. Alex Shockley, statistician, conducted the statistical analysis for this study.
Age at castration appears to influence growth rate of male cattle. The higher pre-weaning weight gains of bulls suggest that the male hormone is an influencing growth factor. However, post-weaning weight gains are lower in bulls castrated at eight months, which tends to nullify their pre-weaning advantage. Stress caused by the operation may have been a factor in this response. Differences in weight gains associated with diethylstilbestrol treatment were obtained whenever used in these tests. This is a progress report of experimental use of diethylstilbestrol in tests with early and late castrates to improve weight gains—a practice not presently recommended by the University of California.