Rumen dynamics of neutral detergent fiber in cattle fed low-quality tropical forage and supplemented with nitrogenous compounds

Revista Brasileira de Zootecnia

Cláudia Batista Sampaio²  Edenio Detmann¹  Isis Lazzarini²  Marjorrie Augusto De Souza²  Mário Fonseca Paulino¹  Sebastião De Campos Valadares Filho¹ 

[1] ,Universidade Federal de Viçosa Programa de Pós-Graduação em Zootecnia Viçosa MG

关键词: rumen degradation;    rumen fill;    signal grass;    supplementation;    urea;    capim-braquiária;    degradação ruminal;    suplementação;    repleção ruminal;    uréia;   

DOI  :  10.1590/S1516-35982009000300023

来源: SciELO

【 摘 要 】

The aim of this work was to evaluate the effects of supplementation with nitrogenous compounds on rumen dynamics of neutral detergent fiber (NDF) in cattle fed low-quality tropical forage. Five crossbred heifers with average live weight of 180 kg and fitted with rumen cannulae were used. The animals were fed ad libitum with signal grass (Brachiaria decumbens Stapf.) hay, which had crude protein (CP) content of 4.86% of dry matter (DM). The five treatments were proposed in order to raise the CP level of diets to 0, 2, 4, 6, and 8 percentile points above the CP level of the forage. The supplement was a mixture of urea, ammonium sulfate, and albumin (4.5:0.5:1.0, respectively). The experiment was carried out according to a 5 × 5 Latin square design, with five experimental periods. The average CP levels in the diets were: 5.19, 7.11, 8.60, 11.67, and 13.02% on DM basis. The potentially degradable NDF was linearly increased according to the CP levels in diet up to 6.97% of CP. From this point, there was stabilization of estimates (47.87% of NDF). The degradation rate of potentially degradable NDF was linearly increased with the CP levels in diets. The rumen flow of fibrous particles (L) showed a linear-response-plateau pattern according to the CP levels in diets. The plateau (maximum estimate) began on 7.24% of CP. The mean retention time in the rumen and the rumen fill effect of undegradable NDF were affect by the CP levels similarly to L, with plateau (minimum) beginning on 6.90 and 6.97% of CP, respectively.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License