Effects of receiving diets based on wet corn gluten feed on performance and morbidity of newly received beef heifers and in vitro fermentation

Two proprietary complete starter diets (RAMP and Test Starter) based on Sweet Bran wet corn gluten feed were compared with a 65%-concentrate receiving diet (control) in terms of performance and health of newly received heifers and in vitro fermentation of diet substrates. In Exp. 1, 2 truckloads of beef heifers (n = 238; average initial BW = 184 kg) were fed the experimental diets during a 35-receiving period. Initial BW did not differ (P > 0.35) among dietary treatments, but BW on d 35 was greater (P = 0.002) for control heifers than for the average of heifers fed the 2 complete starter diets. Average daily gain (P ≤ 0.001), intake of milled feed DM (P ≤ 0.001), and G:F (P ≤ 0.001) were greater for the control diet than for the average of the 2 complete starter diets at all the measurement periods. The proportion of heifers treated one or more times for bovine respiratory disease (P ≥ 0.433) did not differ among the 3 dietary treatments. In Exp. 2, the 3 receiving diets were used to evaluate in vitro total gas production, IVDMD, and VFA proportions. Total gas produced was greater (P = 0.013) for the control than for the average of RAMP and Test Starter substrates. In contrast to gas-production results, IVDMD was greater (P ≤ 0.013) for the 2 Sweet Bran-based substrates than for the control at most incubation times. Total VFA and the acetate:propionate ratio did not differ (P > 0.052) between control and average of the RAMP and Test Starter substrates, but proportion of butyrate was increased (P = 0.002) with the 2 complete starter substrates compared with the control. Results indicate that heifers fed the 2 complete starter diets used in this experiment did not perform as well as control heifers, but dietary treatments did not affect bovine respiratory disease morbidity during the receiving period. Contrasting results for IVDMD and gas production presumably reflect differences in major ingredients of the substrates and perhaps the proportion of soluble components in Sweet Bran.