Terminação de vacas e novilhas com diferentes períodos de confinamento

• Autor(a) principal: Brandão, Bruno Monteiro
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/11156
• topic: Confinamento; Adaptação; Terminação; Vacas; Novilhas; Feedlot; Adaptation; Finishing; Heifes; Cows; CIENCIAS AGRARIAS::ZOOTECNIA::PRODUCAO ANIMAL

The performance, carcass and meat characteristics and economic viability of Nellore cows and heifers feedlot finished during 40 or 60 days were evaluated. The experimental design used was completely randomized with treatments in a 2 x 2 factorial arrangement, with two female categories and two confinement periods. Twenty-two cows with 74.3 months and 22 heifers with 20.4 months were used. The experimental diet included corn silage and concentrate containing 18% CP and 74% NDT. In the 21-days adaptation period, cows showed much lower performance. The food consumption expressed as a percentage of body weight was higher in heifers, with average daily weight gain of 821 and 938 g, while cows practically maintained their weight with average daily weight gain of 62 and -291 g. Heifers were more efficient in feed conversion during adaptation. After the adaptation period, cows showed greater average daily weight gain, with similar feed conversion to heifers. The cold carcass yield was higher (p<0.04) in heifers, which also showed greater subcutaneous fat thickness (P<0.01) with the 40-day finishing, but with no difference to the 60-day finishing. The increase in the feedlot period provided a higher marbling content (P<0.01) in the Longissimus lumborum muscle in both categories, the increase being more evident in cows. The net profit from finishing the heifers was 47.2% higher (P<0.5) in relation to the profit obtained with the cows.