Feeding sorghum dry distillers grains plus solubles to early-weaned beef calves

Abstract

This study evaluated the effect of feeding sorghum dry distillers grains plus solubles (SDDGS) to early-weaned beef calves as an energy/protein source in a sorghum-grain-based diet. Twenty-four castrated Hereford calves (84.6 ± 11.0 kg) were assigned randomly to four rations differing in SDDGS concentrations (0, 130, 260, or 390 g/kg, dry matter [DM] basis), where the SDDGS replaced a mixture of sorghum ground grain (420 g/kg) and soybean meal (580 g/kg) at a balance that ensured a similar supply of crude protein (185 g/kg) and metabolizable energy (12.1 MJ/kg) in the ration. The feeding period lasted for 70 days, with animals individually fed ad libitum in three daily meals. Increasing SDDGS in the diet linearly increased DM intake, fiber and fat intake (P<0.01), without affecting nitrogen intake or DM digestibility (P>0.10). Higher SDDGS did not affect (P>0.10) calves’ BW gain (1.13 kg/d, SE 0.05) or final BW (160.0 kg, SE 8.8), but it did result in a linear drop in gain-to-feed ratio (GF= −0.0012 × + 0.2679; P<0.01). No differences were detected in animal behavior (eating, resting, or ruminating activity) due to treatments (P>0.10). The observed net energy (NE) in the control diet was below the expected value based on feeding standards; as SDDGS replaced a higher proportion of sorghum grain and soybean meal in the control diet, the observed diet NE concentration declined linearly (P<0.01). The highest replacement rate represented a reduction of 15% and 20% in diet NE for maintenance and BW gain, respectively.