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

Abstract

<h2>ABSTRACT</h2> 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 (<i>P</i> = 0.008) BW and had 0.9 kg/d less (<i>P</i> = 0.004) milk production, which resulted in a trend (<i>P</i> = 0.06) for slower calf ADG than for cows fed CGF. There was no difference in manure N (<i>P</i> = 0.13), but cows fed CGF did have greater (<i>P</i> = 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 (<i>P</i> = 0.07) to lose more weight than those fed CGF. In addition, no differences were detected in milk production (<i>P</i> = 0.20) or calf ADG (<i>P</i> = 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.