Effect of preweaning feeding of pasteurized and nonpasteurized milk on postweaning weight gain of heifer calves on a Californian dairy

The effect of preweaning feeding of pasteurized colostrum and pasteurized waste milk on postweaning performance of dairy heifers on a dairy in the Central Valley of California was investigated as an extension of a clinical trial examining the effect of preweaning growth and morbidity on performance at weaning. Of the 150 heifer calves originally enrolled in the field trial, 115 calves (59 treatment, 56 controls) were followed to about 6 months of age, during which time their weights were measured. After weights were adjusted for several potential risk factors and effect modifiers, calves fed pasteurized colostrum and pasteurized waste milk were 3.7 kg heavier at 180 days of age than those fed nonpasteurized colostrum and nonpasteurized milk.