Effect of Increasing Ration Fiber with Soybean Mill Run on Digestibility and Lactation Performance

Abstract

Lactating Holstein cows (18) were fed 3 complete rations ad lib in a 2-period change-over design. The concentrate-to-alfalfa silage ratio (dry basis) was 57:43. Soybean mill run replaced corn grain in the concentrate mixture at 0, 26.9 and 48.9%. Crude fiber in the complete rations was 13%, 18% and 23%. Treatments did not significantly affect dry matter intake, digestible dry matter intake, production of 4%-fat-corrected milk, milk fat test (mean 4.1%), dry matter digestibility (mean 64%) or rumen volatile fatty acids. Means for dry matter intake [kg/100 kg body weight] were 2.92, 2.89 and 2.93 for 13, 18 and 23% fiber. Means for fat-corrected milk [kg/day] were 19.0, 19.9 and 18.5. Digestibility of fiber components was improved for the 2 rations containing soybean mill run. Digestibilities (%) for rations were acid detergent fiber 48.3, 60.3 and 62.4; cellulose 57.9, 67.5 and 70.2. Soybean mill run replaced up to 53.7% of the corn in the concentrate mixture without adversely affecting lactation performance, efficiency or health status. However, there were no benefits to performance when additional fiber beyond the National Research Council''s minimum of 13% was included.