Feedlot finishing of steers of different genotypes of Hereford x Nellore

[摘要] - This experiment was conducted to evaluate the performance in feedlot finishing period of steers with genotype of 100 Hereford (H), 62/38 H Nellore (N), 50/50 HN, 25/75 HN. Twenty-four steers, twenty months old, feedlot confined by 126 days, were used. The diet with 12.7% of crude protein, was constituted by 57.5:42.5 forage to concentrate ratio on dry matter (DM) basis. The forage was corn silage + chopped sugar cane (relation 1:1). The regression was significant for the average daily weight gain (= .59910+ .02068X- .00013X2; r2= .8890; P<.0041), daily DM intake (=4.76025+ .13037X- .00099X2; r2= .9369; P<.0010), DM intake per metabolic weight (=67.64281+ .60047X- .00475X2; r2= .7883; P<.0206) and expressed as percentage of live weight (=1.9217 + .0169X - .00012X2; r2= .6624; P<.0466), with X as the percentage of H. The average daily gain was lower for 25/75 HN steers which also showed the lowest DM intake. The dry matter intake per metabolic weight was higher for 62/38 HN, followed by the 50/50HN, and lower for 100H and 25/75 HN. The feed:gain ratio was not affected by the genetic groups. There was an expressive decrease in steers daily weight gain, when the proportion of Nellore surpassed 50%.

[学科分类] 兽医学

[关键词] Bos indicus;Bos taurus;crossbreeding;performance     IntroduçãoO cruzamento;quando bem direcionado;é ferramenta importante para o produtor melhorar a produtividade do rebanho