Internal organs and gastrointestinal tract of feedlot finished steers of advanced generations of rotational crossbreeding between Charolais and Nellore

Revista Brasileira de Zootecnia

Alves Filho, Dari Celestino³  Silveira, Magali Floriano da⁴  Brondani, Ivan Luiz³  Restle, João¹  Leite, Daniel Terra⁴  Menezes, Luís Fernando Glasenapp de⁴  Kuss, Fernando² 

[1] UFG, Coiânia;UFRGS;UFSM;Universidade Federal de Santa Maria

关键词: Bos indicus;    Bos Taurus;    crossbreeding;    heterosis;    heterozygosis;    empty body weight    Introdução Os grupos genéticos bovinos encontrados no Brasil;    especialmente na Região Sul;    são muito variados;    pois muitos criadores ainda escolhem as raças pela preferência pessoal;    ou por modismo;    em detrimento da escolha pela produtividade;   

DOI  :  10.1590/S1516-35982007000100015

学科分类：兽医学

来源: Universidade Federal de Vicosa

【 摘 要 】

The objective of this trial was to investigate the effect of heterosis and genetic group on the yield and weight of internal organs and gastrointestinal tract (GIT) of feedlot purebred (Charolais C and Nellore N) and crossbred steers from second (G2) (¾C ¼N and ¾N ¼C), third (G3) (5/8C 3/8N and 5/8N 3/8C) and fourth (G4) (11/16C 5/16N and 11/16N 5/16C) generations of rotational crossbreeding slaughtered at 23 month of age. Crossbred steers from G2, G3 and G4 had, respectively, 14.95, 17.25 and 18.46% higher empty body weight (EBW) than that from purebred animals. A positive heterosis for cold carcass yield expressed as a proportion of EBW (CCYEBW) was observed in G2, G3, and G4. Weights of heart, lungs, and kidneys adjusted for EBW were lower on crossbred compared to purebred steers; the heterosis was significant for the weights of heart (-18.29%) and kidneys (-14.29%) in G3 and for that of lungs (-13.45%) in G4. Weights of all organs of the GIT either expressed as 100 kg of EBW or as proportion of slaughter body weight (SBW) were lower on crossbred than on purebred steers with the exception of rumen weight in G2. Retained heterosis was positive and significant for EBW, CCYEBW and liver weight. However, it was negative for amount of blood and weights of heart and small plus large intestines when expressed as 100 kg of EBW and SBW. Within purebred animals, N showed greater CCYEBW (61.64%) than C (57.09). Conversely, weights of rumen, abomasum, small plus large intestine, and GIT were all higher on C than N steers; excepting for small plus large intestine, the same was observed when weights of the remaining GIT components were expressed as proportion of EBW and SB. These differences partially explain the increased carcass yield on N steers.

【 授权许可】

CC BY-NC