Effect of Dried Distillers Grains Supplementation on Calves Grazing Bermudagrass Pasture or Fed Low-Quality Hay

The objective of the following experiments was to examine the effect of dried distillers grains plus solubles (DDGS) supplementation of calves grazing bermudagrass (Cynodon dactylon) pasture during summer (Exp. 1) or fed lowquality tall fescue hay (Exp. 2, Festuca arundinacea) during winter months. In Exp. 1, a total of 36 steers (261 kg) were randomly assigned to one of nine 0.81-ha pastures receiving 0, 0.9, or 1.8 kg/d DDGS (as-fed basis). Over the 84 d, supplementation increased ADG by 0.24 kg/d (P = 0.02); however, the 1.8 kg/d supplementation rate did not improve ADG above the 0.9 kg/d supplementation rate (P = 0.54). Supplementation increased pasture BW gains 98.5 kg/ ha (P = 0.02) with a supplemental G:F of 0.22. In Exp. 2, a total of 84 steers (220 kg) were randomly assigned to 1 of 12 pens and given free-choice access to tall fescue hay plus 0, 0.3, 0.6, or 1.2% BW DDGS (as-fed basis). The DDGS increased ADG in a cubic manner (P = 0.01) over the 82-d supplementation period. Average daily gain increased by 0.4, 0.14, and 0.23 kg/d for the first, second, and third incremental increase in DDGS. Economic evaluation of Exp. 1 indicated the probability of at least breaking even when supplementation was 0.78 and 0.69 for the 0.9 and 1.8 kg/d supplementation rate, respectively. Economic evaluation of Exp. 2 indicated the probability of at least breaking even with supplementation was 0.99, 0.87, and 0.83 at 0.3, 0.6, and 1.2% BW DDGS, respectively.