Data/hora: 17/06/2024 08:11:07

Biblioteca(s): 	Embrapa Pantanal.	
Data corrente: 	20/03/2002	
Data da última atualização: 	05/07/2018	
Autoria: 	MARIANTE, A. da S.	
Afiliação: 	ARTHUR DA SILVA MARIANTE, Cenargen.	
Título: 	Growth and reproduction in Nellore cattle in Brazil: genetic parameters and effects of environmental factors.	
Ano de publicação: 	1978	
Fonte/Imprenta: 	Florida: University of Florida, 1978.	
Páginas: 	133 p.	
Idioma: 	Inglês	
Notas: 	Ph.D. Dissertation.	
Conteúdo: 	The objectives of this study were to determine the effects of various genetic and environmental factors on growth traits and reproductive performance of a herd of Nellore cattle in central Brazil. Weights at birth and at weaning (8 mo.), 12, 18, and 24 months of age collected over a 15-year period from 2,282 calves, were analyzed by least squares methods. Least squares means for these weights were 30.2+-.7, 187.5+-.0, 215.5+-.3, 282.6+-2.8, and 354.9+-4.0 kg. Year and month of birth, sire and sex of calf affected (P<.01) weights at all ages. Age of dam had a significant (P<.10) effect on calf weight at 24 monts of age, and a highly significant effect on weights at the other ages. Heritability, estimated by paternal halfsib correlations, was .62+-.14, .12+-.14, .14+-.05, .13+-.05, and .18+-.06 for weight at birth, 8, 12, 18 and months, respectively. All genetic, phenotypic and environmental correlations between weights at different ages were positive.  Correlations between weights tahen at ages closer together tended to be higher than those taken at more distant ages. Data from 335 calvings collected over an 11-year period were analyzed for age at first calving by least squares methods. The least squares mean for age at first calving was 40.3+-.7 months. Variables that significantly affected this traid were weight of the cow at birth, and at 8, 12, 18, and 24 months of age (P<.05), and sire of calf (P<.01). Heritability of age at first calving, estimated by paternal half-sib correlations, was .09+-12. Genetic...	
Palavras-Chave: 	Growth trait.	
Thesagro: 	Crescimento; Gado Nelore; Pecuária; Reprodução Animal; Zootecnia.	
Thesaurus Nal: 	Brazil; cattle breeding; reproduction; reproductive performance.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Pantanal (CPAP)	
Exemplares: 	CPAP - (34089-1) - UPC - TS - PP - TS89.00460 -  - 1989.00460 - DIS