Intake,digestibility and nitrogen utilization in cattle fed tropical forage and supplemented with protein in the rumen,abomasum,or both  

作　　者：Luana Marta de Almeida Rufino Edenio Detmann Daianyíris Gomes William Lima Santiago dos Reis Erick Darlisson Batista Sebastiao de Campos Valadares Filho Mário Fonseca Paulino 

机构地区：[1]Department of Animal Science,Universidade Federal de Viaosa [2]Department of Animal Science,Universidade Federal Rural da Amaznia

出　　处：《Journal of Animal Science and Biotechnology》2016年第4期544-553,共10页畜牧与生物技术杂志（英文版）

基　　金：Fundacao de AmparoàPesquisa de Minas Gerais(FAPEMIG);the INCT Ciência Animal for financial support

摘　　要：Background： There is little information in the tropics with regard the comparative understanding of how an increased nitrogen supply in the rumen or in the intestines affects efficiency of nitrogen utilization in cattle. This study evaluated the effects of supplementation with nitrogenous compounds in the rumen, abomasum, or both on intake, digestibility and the characteristics of nitrogen utilization in cattle fed tropical forage. Four rumen- and abomasum-fistulated Nellore bulls （227 ± 11 kg） were used. Four treatments were evaluated： control, ruminal supplementation （230 g/d of supplemental protein in the rumen）, abomasal supplementation （230 g/d of supplemental protein in the abomasum）, and ruminal and abomasal supplementation （115 g/d protein in both the rumen and the abomasum）. The basal forage diet consisted of Tifton 85 hay with a crude protein （CP） level of 78.4 g/kg dry matter. Casein was used as a supplement. The experiment was conducted using a 4 x 4 Latin square. Results： There were no differences between the treatments （P 〉 0.10） with regard to forage intake. The intake and tota digestibility of CP increased （P 〈 0.01） with supplementation. The nitrogen balance in the body increased （P 〈 0.01） and muscle protein mobilization decreased （P 〈 0.01） with supplementation, regardless of the supplementation site. The efficiency of nitrogen utilization did not differ among the treatments （P 〉 0.10）. Conclusions： The supplementation of cattle fed tropical forage with protein in the rumen, abomasum, or both similarly increased the nitrogen accretion in animal, which reflects improvements on nitrogen status in animal body.Background： There is little information in the tropics with regard the comparative understanding of how an increased nitrogen supply in the rumen or in the intestines affects efficiency of nitrogen utilization in cattle. This study evaluated the effects of supplementation with nitrogenous compounds in the rumen, abomasum, or both on intake, digestibility and the characteristics of nitrogen utilization in cattle fed tropical forage. Four rumen- and abomasum-fistulated Nellore bulls （227 ± 11 kg） were used. Four treatments were evaluated： control, ruminal supplementation （230 g/d of supplemental protein in the rumen）, abomasal supplementation （230 g/d of supplemental protein in the abomasum）, and ruminal and abomasal supplementation （115 g/d protein in both the rumen and the abomasum）. The basal forage diet consisted of Tifton 85 hay with a crude protein （CP） level of 78.4 g/kg dry matter. Casein was used as a supplement. The experiment was conducted using a 4 x 4 Latin square. Results： There were no differences between the treatments （P 〉 0.10） with regard to forage intake. The intake and tota digestibility of CP increased （P 〈 0.01） with supplementation. The nitrogen balance in the body increased （P 〈 0.01） and muscle protein mobilization decreased （P 〈 0.01） with supplementation, regardless of the supplementation site. The efficiency of nitrogen utilization did not differ among the treatments （P 〉 0.10）. Conclusions： The supplementation of cattle fed tropical forage with protein in the rumen, abomasum, or both similarly increased the nitrogen accretion in animal, which reflects improvements on nitrogen status in animal body.

关 键 词：CASEIN Nitrogen balance Rumen ammonia nitrogen Supplementation 3-methylhistidine 

分 类 号：S823.5[农业科学—畜牧学]