Ruminal degradability of bypass fat and protein of certain commonly used feedstuffs in dairy rations

Abstract

Studies were conducted to determine the rumen degradability of protein of certain commonly used feed ingredients and degradability of bypass fat used in dairy rations. In situ crude protein (CP) disappearance of groundnut cake, soybean extraction, cottonseed cake, maize gluten meal, wheat bran, rice bran, maize, 0.3, 0.6 and 0.9% (of CP) formaldehyde treated soybean extraction, and in situ fat disappearance of bypass fat in the rumen at different incubation periods were determined by nylon bag technique using 3 adult crossbred steers. The effective degradability was calculated for an assumed outflow rate of 5%/h. The effective CP degradability of groundnut cake, soybean extraction, cottonseed cake, maize gluten meal, wheat bran, rice bran, maize, 0.3, 0.6 and 0. 9% (ofCP) formaldehyde treated soybean extraction was 86, 74, 66, 21, 73, 65, 63, 66, 48 and 26%, respectively. The effective fat degradability of bypass fat was 86%. The results indicated that maize gluten meal is a good source of bypass protein. Soybean extraction although extensively degraded in the rumen, contribute fairly more amount of undegradable protein than rumen degradable protein at an outflow rate of 5%/h, when it is treated with 0.6 and 0.9% (of CP) formaldehyde. The bypass fat supplement prepared from rice bran acid oil is a good source of energy in which about 86% of fat would be available at the lower tract of ruminants. Therefore, maize gluten meal, 0.9% formaldehyde treated soybean extraction and protected fat can be included in the rations of dairy animals forimproved productive performance