The Effects of Corn Silage Inclusion in Pre-Weaned Calf Diets

Abstract Text: The objective was to evaluate the effects of corn silage inclusion in starter feed provided to calves after birth through weaning.  Thirty six heifer calves and 9 bull calves were reared at the U.S. Dairy Forage Research farm where they were individually housed in hutches.  All treatments were fed pasteurized milk with either all calf starter (C), 60% calf starter and 40% corn silage (CC), or all corn silage (CS).  Feed intake and health scores were recorded daily.  Every other week, calves were sampled for weight, withers and hip height, heart girth, serum protein, hematocrit, blood urea nitrogen, glucose, and beta-hydroxybutyrate.  Nine bull calves were sacrificed one week post-weaning at 8 wk of age.  Rumen and intestinal tissue were collected and preserved with formalin for later analysis.   One intestinal tissue sample was taken at consistent lengths from the duodenum, jejunum, ileum, and colon; from each tissue sample, three blocks were cut and 24 tissue slides were stained from each block for measurement.  Three rumen samples were taken from four areas within the rumen and twelve random papillae per sample were measured for length and width.  Daily and biweekly measurements were analyzed using a repeated measures analysis of the Mixed procedure and intestinal and ruminal measurements were analyzed using the General Linear Model procedure of SAS 8.3 (2010).  Initial growth measurements were used as covariates for growth analysis and significance was found at P<0.05.  Feed intake was not different between treatments however there was a treatment by week interaction (P<0.0001).  Least squares means of rumen papillae lengths were different (9.3, 7.5, and 3.9 ± 0.3 mm for treatments C, CC, and CS, respectively; P<0.05).  Jejunal villi lengths tended to be different (97.65, 105.61, and 89.57 ± 5.8 um for treatments C, CC, and CS, respectively; P=0.12) and crypt depths were different (46.10, 48.58, and 38.69 ± 2.8 um for treatments C, CC, and CS, respectively; P=0.03).  Treatments did not differ for weight (P<0.15), heart girth (P<0.4), hip height (P<0.7), withers height (P<0.15), serum protein (P<0.8), and hematocrit values (P<0.6).  This data indicates the inclusion of corn silage to starter feed does not affect growth and overall feed intake but may affect weekly feed consumption.  Solely feeding corn silage as starter feed stunted the growth of the rumen papillae and reduced crypt depths indicating reduced absorption and efficiency.  Future milk production will be monitored.

Keywords: calves, corn silage, calf starter feed