Nutrient Digestibility Depressions in Corn Silage-Corn Grain Mixutres Fed to Steers

Publisher Website
Google Scholar
Abstract
Thirty nutrient digestibility and N balance determinations were made on each of six steers (250 kg) fed each of five diets containing silage and(or) cracked corn grain ad libitum. Measurements were made by 7-day total collection. All diets were supplemented with a soybean meal-mineral mixture at 10% of the diet dry matter. Digestibilities of dry matter, starch, neutral detergent fiber and protein averaged 68, 98) 63 and 63% for immature silage; 67, 98, 49 and 60% for mature silage; 70, 86, 53 and 61% for a 1:2 ratio of immature silage to grain; 70, 89, 37 and 62% for a 1:2 ratio of mature silage to grain, and 84, 98, 54 and 74% for the all-grain diet. Dry matter digestion coefficients for the silage-grain mixtures averaged 11% less (P<.01) than those calculated from the weighted means for the feeds fed singly. Depressions in starch, fiber and protein digestibilities accounted for 59, 26 and 14% of the depression in dry matter digestibility for the immature silage-grain mixture and 53, 36 and 10% of the depression for the mixture containing mature silage. No relationship was found between dry matter digestibility and dietary intake of steers consuming single-feed diets; however, marked negative relationships (r = −.8) existed among the steers consuming the silage-grain mixtures over a range of intake from 2.4 to 3.1 times maintenance. These data suggest that negative associative effects between cracked corn grain and corn silage would not be observed if the diets were fed to steers at levels below approximately 1.5 to 2 times maintenance. Incomplete starch digestibility is apparantly the major reason for the decreased efficiency observed when corn silage and grain are fed as mixtures. Copyright © 1981. American Society of Animal Science . Copyright 1981 by American Society of Animal Science

This publication has 0 references indexed in Scilit: