Effect of Level of Wet Corn Gluten Feed and Corn Grain on Nutrient Digestibility and Performance

Abstract

Thirty-six multiparous Jersey cows averaging 95 d postpartum were used in a 14-wk trial to study wet corn gluten feed and corn grain levels in rations based on hay for their effects on nutrient digestibility and milk production and composition. Cows were assigned randomly to one of six experimental TMR diets based on alfalfa and orchardgrass hay. Wet corn gluten feed was fed at 10, 20, or 30% of dietary DM. Two levels of corn grain (low or moderate) were fed within each level of wet corn gluten feed. Substituting wet corn gluten feed for hay decreased ruminal ammonia and total VFA concentrations and molar proportions of butyrate and increased propionate and valerate. Molar proportions of acetate and acetate to propionate ratio decreased whereas molar proportions of propionate and valerate and nutrient digestibility increased as corn grain increased. An interaction between level of wet corn gluten feed and corn grain was observed for apparent digestibility of CP and ADF because of lower digestibility of the 30% wet corn gluten feed diet with moderate levels of corn grain. Yield of milk protein increased linearly with increasing levels of wet corn gluten feed. Milk yield tended to be higher when moderate levels of corn grain were fed.