Influência de Alguns Fatores de Ambiente sobre os Escores de Conformação, Precocidade e Musculatura à Desmama em um Rebanho da Raça Nelore
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Data
2001-12-01
Autores
Jorge Júnior, João [UNESP]
Pita, Fabiano Veraldo da Costa
Fries, Luiz Alberto
Albuquerque, Lucia Galvão de [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira de Zootecnia
Resumo
Dados de 23.251 animais da raça Nelore desmamados no período de 1994 a 1997, pertencentes à Agropecuária Jacarezinho Ltda., foram analisados para se avaliar os efeitos ambientais da idade da vaca, data de nascimento e idade à desmama sobre os escores visuais de conformação (C), precocidade (P) e musculatura (M). Todos os efeitos estudados influenciaram significativamente os escores visuais. As análises indicaram que as vacas que pariram aos sete, oito e nove anos, obtiveram os melhores resultados para os escores visuais de C, P e M, assim como os animais que nasceram mais cedo dentro da estação de parição. Para a idade à desmama foi constatado que, quanto mais tarde o animal for desmamado, melhores serão seus escores. Os animais que desmamaram com 220 dias tiveram os melhores escores, enquanto os piores escores foram daqueles que desmamaram com 140 dias. Portanto, para se ter maior precisão na avaliação genética dos indivíduos jovens, fatores de correção para idade da vaca, data juliana de nascimento e idade à desmama devem ser utilizados sobre os escores de conformação, precocidade e musculatura.
Data on 23,251 Nelore calves weaned from 1994 to 1997, belonging to Agropecuária Jacarezinho Ltda., were analyzed to estimate the influence of environmental effects of age of dam, julian date of birth and age of calf at weaning on visual scores of conformation (C), precocity (P) and musculature (M). All effects significantly influenced the visual scores. The analyses showed that the calves with the best scores of C, P and M at weaning were those from dams with 7, 8 and 9 years of age. The best visual scores were from animals that were born earlier in the calving season. For age at weaning, as older was the animal better were its scores. The highest scores were those from animals weaned at 220 days of age and the smallest scores were from animals weaned at 140 days of age. Therefore, to increase the accuracy of genetic evaluations of young animals, adjusting factors for age of dam, julian date of birth and age at weaning, should be used, for conformation, precocity and musculature scores.
Data on 23,251 Nelore calves weaned from 1994 to 1997, belonging to Agropecuária Jacarezinho Ltda., were analyzed to estimate the influence of environmental effects of age of dam, julian date of birth and age of calf at weaning on visual scores of conformation (C), precocity (P) and musculature (M). All effects significantly influenced the visual scores. The analyses showed that the calves with the best scores of C, P and M at weaning were those from dams with 7, 8 and 9 years of age. The best visual scores were from animals that were born earlier in the calving season. For age at weaning, as older was the animal better were its scores. The highest scores were those from animals weaned at 220 days of age and the smallest scores were from animals weaned at 140 days of age. Therefore, to increase the accuracy of genetic evaluations of young animals, adjusting factors for age of dam, julian date of birth and age at weaning, should be used, for conformation, precocity and musculature scores.
Descrição
Palavras-chave
Beef cattle, calf age, cow age, julian date of birth, Visual score, data juliana de nascimento, Escores visuais, Gado de corte, idade do bezerro à desmama, idade da vaca
Como citar
Revista Brasileira de Zootecnia. Sociedade Brasileira de Zootecnia, v. 30, n. 6, p. 1697-1703, 2001.