Feedlot confined crossbreed steers fed with different forage to concentrate ratios. 1. Apparent nutrient digestibilities, weight gain and feed:gain ratio

Revista Brasileira de Zootecnia

Pereira, José Carlos¹  Oliveira, José Victor de²  Queiroz, Augusto César de¹  Mâncio, Antonio Bento¹  Resende, Flávio Dutra de² 

[1] UFV, Viçosa;Instituto de Zootecnia, Colina

关键词: average daily gain;    beef cattle;    concentrate level;    digestibility;    nutrient   IntroduçãoEstudos de como a relação volumoso:concentrado influi na cinética da digestão;    bem como na utilização dos alimentos;    são fundamentais para formular e manipular as dietas utilizadas;    visando a máxima eficiência da mesma;   

DOI  :  10.1590/S1516-35982001000100037

学科分类：兽医学

来源: Universidade Federal de Vicosa

【 摘 要 】

- The objective of this work was to evaluate the effects of the forage to concentrate ratio on the weight gain and feed: gain, and to determine the apparent digestibility of the nutrients of 25 and 20 crossbred steers averaging 310 kg LW, respectively. Five full fed diets based on tanzaniagrass hay and concentrate, with different forage to concentrate ratio (85:15, 70:30, 55:45; 40:60; and 25:75) were used. The regression analysis of the coefficienties of apparent digestible dry matter, digestible organic matter, neutral detergent fiber, digestible protein and gross energy in function of the concentrate level in the diets presented quadratic effect and the maximum estimated coefficienties were 67.0, 70.0, 51.0 42.0 74.0 and 69.0 %, for the levels of 54, 58, 28, 12, 34 e 77 % of concentrate in the diets, respectively. The average daily gain (ADG) linearly increased with the increase of the concentrate level in the diets. There was an increase of 0.00895 kg/day in the ADG for each percent increase on the concentrate level in the diets, from 15.0 to 75.0 %. In the same range, the feed: gain of DM, CP, and GE increased 0.08; 0.011468; and 0,50646, respectively, for each percent increase on the concentrate level in the diets. The maximum nutrient digestion for the maximum efficiency of nutrient utilization occurred with the intake of neutral detergent fiber ranged from 1.25 to 1.02% LW for crossbred steers

【 授权许可】

CC BY-NC