Data/hora: 01/06/2024 13:33:25

Biblioteca(s): 	Embrapa Gado de Leite.	
Data corrente: 	08/07/2017	
Data da última atualização: 	27/01/2023	
Autoria: 	CANAZA-CAYO, A. W.; LOPES, P. S.; COBUCI, J. A.; MARTINS, M. F.; SILVA, M. V. G. B.	
Afiliação: 	Ali William Canaza-Cayo, National University of Altiplano, Puno, Peru; Paulo Sávio Lopes, UFV; Jaime Araújo Cobuci, UFRGS; MARTA FONSECA MARTINS, CNPGL; MARCOS VINICIUS GUALBERTO B SILVA, CNPGL.	
Título: 	Genetic parameters of milk production and reproduction traits of Girolando cattle in Brazil.	
Ano de publicação: 	2017	
Fonte/Imprenta: 	Italian Journal of Animal Science, v. 16, 2017.	
Páginas: 	9 p.	
Idioma: 	Inglês	
Conteúdo: 	The objective of this study was to estimate the heritability and genetic, phenotypic, and environmental correlations between 305-day milk yield (305MY), age at first calving (AFC), calving interval (CI) and dry period length (DPL), as well as to compare the productive and reproductive performances of several groups of Girolando cows during their first, second and third parturitions in Brazil. Genetic parameters were estimated using uni- and bi-trait analyses via restricted maximum likelihood (REML). Heritability estimates were similar between uni- and bi-trait analyses and varied from 0.20 to 0.28, 0.00 to 0.08 and 0.07 to 0.14 for 305MY, CI and DPL, respectively, whereas AFC was 0.20. Genetic correlations between 305MY and AFC (?0.49) or DPL (?0.40 to ?0.79) show a favourable association. However, an unfavourable genetic association was verified between 305MY and CI (0.59) in the first calving. Environmental and phenotypic correlations between 305MY and CI or DPL showed a favourable association (?0.25 to ?0.42 and ?0.14 to ?0.44). Concerning the cow breed group, a decrease in 305MY was observed as the fraction of the Gyr breed increased, whereas animals from the 1/2 Holstein +1/2 Gyr crossbreeding group yielded better performances for AFC and CI. These results reveal large genetic, phenotypic and environmental variations that could be used in selection programmes.	
Palavras-Chave: 	Genetic parameters.	
Thesaurus Nal: 	Girolando; milk yield; reproductive traits.	
Categoria do assunto: 	L Ciência Animal e Produtos de Origem Animal	
Registro original: 	Embrapa Gado de Leite (CNPGL)	
Exemplares: 	CNPGL - (23604-1) - UPC - AP - DD -  -  -  - DIS