Responses of Dairy Cows to Different Amounts of Wheat Middlings in the Concentrate Mixture

Abstract

Eighteen lactating dairy cows were used in each of two feeding trials to evaluate the effect of different amounts of wheat middlings in the ration on intake and milk yield. Concentrate mixtures containing 0, 20, and 40% and 0, 40, and 60% middlings in two respective trials were calculated to be isocaloric and isonitrogenous. These made up 60% of the total ration with alfalfa hay as the forage component. Samples for ruminal ammonia and blood plasma urea nitrogen were taken 3 h after concentrate feeding. Milk yield of cows fed concentrate mixtures containing 20 or 40% middlings was similar to that of cows fed the control ration; however, yield of those fed a concentrate mixture with 60% middlings was decreased. Milk fat percentage was similar for all groups within trials. Concentration of ruminal ammonia was higher in cows fed rations containing middlings, whereas effect on concentration of plasma urea nitrogen was inconsistent. Similar feed consumption for all treatment groups indicated no ration acceptability problems when middlings were as much as 60% of the concentrate mix. © 1987, American Dairy Science Association. All rights reserved.