Effects of corn silage inclusion in preweaning calf diets

The objective of this research was to evaluate the effects of corn silage inclusion in starter feed provided to calves after birth through weaning at 7 wk of age. Thirty-six heifer calves and 9 bull calves were individually housed in hutches. Calves in treatment groups received pasteurized milk with all calf starter, 25% calf starter and 75% corn silage, or all corn silage. Values were recorded daily for feed intake and health, which included fecal, respiratory, and attitude scores; and at wk 2, 4, and 8 for concentrations of serum protein, hematocrit, and serum beta-hydroxybutyrate. Body weight, withers height, and hip height were measured at wk 2, 4, 8, and 52. Nine bull calves (3/treatment) were killed at 8 wk of age for assessment of rumen and intestinal tissue morphology. Feed intake and average daily gain were not different among treatments. Least squares means of rumen papillae lengths were significantly different and decreased as corn silage inclusion increased. Crypt depths and total thickness of epithelium were reduced for the corn silage group. Least squares means of body weight, heart girth, hip height, withers height, serum protein, hematocrit, and beta-hydroxybutyrate concentrations did not differ among treatments. These data indicated that the mixture of corn silage and starter did not affect growth, feed intake, or intestinal morphology but did affect rumen wall morphology. Feeding solely corn silage as starter feed stunted the growth of rumen papillae and tended to impair intestinal morphology, indicating that only calf starter or a mixture of calf starter and corn silage is more appropriate.