Herd Data Measures of the Effect of Certain Environmental Influences on Dairy Cattle Production

Summary Herd data information on 967 cows in 47 Holstein-Friesian herds of Wisconsin was analyzed by multiple regression techniques to determine the effect of nine environmental influences on production. Results were similar to those reported by other workers for age at calving, number of days carrying calf while milking, length of preceding dry period and month of freshening. Statistically significant regressions were obtained for milk and fat yield on selection rating, pounds T.D.N. fed daily per 1,000 lb. body weight, nutritive ratio, condition at calving and herd size. The regressions of fat test on selection rating, T.D.N. feeding rate, condition at calving and herd size were statistically significant but unimportant. The regression of test on nutritive ratio was not significant.