Influences of Corn Co-products in Limit-Fed Rations on Cow Performance, Lactation, Nutrient Output, and Subsequent Reproduction

Two experiments were conducted to evaluate the effects of corn gluten feed (CGF) or dry distillers grains with solubles (DDGS) in limit-fed diets on cow performance, lactation, nutrient output, and reproduction. Cows were maintained in concrete lots with open-front sheds and fence-line bunks. In Exp. 1, Simmental cows (n = 100) were blocked by age and calving date and assigned to 12 pens. Cows were fed 4.5 kg/d of alfalfa hay and isocaloric amounts of CGF (5.9 kg/d) or DDGS (5.55 kg/d) to meet requirements. The cows fed DDGS lost 16 kg less (P = 0.008) BW and had 0.9 kg/d less (P = 0.004) milk production, which resulted in a trend (P = 0.06) for slower calf ADG than for cows fed CGF. There was no difference in manure N (P = 0.13), but cows fed CGF did have greater (P = 0.04) manure P than cows fed DDGS. In Exp. 2, Simmental cows (n = 114) were blocked by age and calving date and assigned to 12 pens. Cows were fed 2.3 kg/d of ground cornstalks and isocaloric amounts of CGF (7.7 kg/d) or DDGS (7.2 kg/d) to meet requirements. In contrast to Exp. 1, the DDGS cows tended (P = 0.07) to lose more weight than those fed CGF. In addition, no differences were detected in milk production (P = 0.20) or calf ADG (P = 0.57). In both experiments, no differences were detected in reproductive performance. Corn co-products can be included up to 75% of a limit-fed diet. The higher fat content of DDGS compared with CGF did not improve reproduction.