Complete Rations for Dairy Cattle. III. Evaluation of Protein Percent and Quality, and Citrus Pulp-Corn Substitutions

Abstract

An experiment with complete rations containing 25.0% sugarcane bagasse pellets evaluated protein requirements of lactating cows and how well these requirements could be satisfied with urea. Several other objectives also were evaluated with 3 × 3 Latin squares. Treatments of basal rations and two increments of soybean meal were factorialized with two percents of citrus pulp and two quantities of methionine hydroxy analog which were fed continuously. The experiment involved 36 cows fed one of the three urea or one of the three soybean meal percents in each of three 4-wk periods. (1) High-corn (8.0% citrus pulp) depressed fat percent compared to 43.1% citrus pulp diets. (2) Urea depressed feed intake at 1.7 and 3.0%, particurlary in the high-corn diets. (3) Increments of soybean meal increased solids corrected milk production as compared to basal, but urea increments did not. Methionine hydroxy analog increased fat yield in cows receiving soybean meal diets but was a detriment to feed intake and solids corrected milk in high urea rations. © 1975, American Dairy Science Association. All rights reserved.