Performance characteristics of beef cows program fed by-products from corn ethanol production1

The objective of this experiment was to evaluate the efficacy of program-fed, corn-silage-based diets containing reduced-fat, modified wet corn distillers grains (RFDGS); high-fat, modified wet corn distillers grains (HFDGS); or high-fat, condensed corn distillers solubles (HFCDS) containing 8.01, 10.53, and 10.99% ether extract (crude fat), respectively, on beef cow and calf performance. Angus × Simmental crossbred cows (n = 128) were program fed 1 of 4 dietary treatments for 206 d beginning in the third trimester through calf weaning. Cows were blocked by parity (first parity and 2 or more parities) and stratified within parity by BW subject to variation in BCS to 16 pens. Each block was equally represented within treatment. Control cows were fed diets based on corn silage, shelled corn, and soybean meal to provide 12.0% CP (T1). In treatment diets, corn silage and either RFDGS (T2) or HFDGS (T3) replaced shelled corn and soybean meal to provide 12.0% CP. High-fat, condensed distillers solubles (T4) replaced shelled corn and a portion of soybean meal to provide 12.0% CP. Cow DMI per day was lower (P = 0.01) for T3 comparing 10.13 ± 1.12, 9.88 ± 1.02, 8.07 ± 0.88, and 10.08 ± 1.20 kg for T1, T2, T3, and T4, respectively. Crude fat composition of the diets was different (P = 0.001), where T1 < T2 < T3 = T4. A difference (P = 0.02) was observed for milk production, where T4 > T2 and T3, T1 = T4, and T1 = T2 = T3. Milk urea nitrogen differed between treatments (P = 0.02), where T1 > T2 and T3, T4 = T1, and T4 = T2 = T3. No differences (P > 0.05) between treatments were observed for calf BW and cow BW and BCS at the end of the feeding period. Calf birth weight tended (P = 0.10) to be lower for T3 compared with T1, T2, and T4. In corn silage-based diets when beef cows are program fed to maintain similar BCS, HFDGS, RFDGS, and HFCDS can replace shelled corn and soybean meal, with similar performance.