Data/hora: 17/06/2024 17:10:53

Biblioteca(s): 	Embrapa Gado de Leite.	
Data corrente: 	30/12/2019	
Data da última atualização: 	06/02/2024	
Autoria: 	DALTRO, D. DOS S.; PADILHA, A. H.; GAMA, L. T. DA; SILVA, M. V. G. B.; PANETTO, J. C. do C.; MACHADO, J. D.; BRACCINI NETO, J.; COBUCI, J. A.	
Afiliação: 	DARLENE DOS SANTOS DALTRO; ALESSANDRO HAIDUCK PADILHA; LUÍS TELO DA GAMA; MARCOS VINICIUS GUALBERTO B SILVA, CNPGL; JOAO CLAUDIO DO CARMO PANETTO, CNPGL; JULIANA DEMENTSHUK MACHADO; JOSÉ BRACCINI NETO; JAIME ARAUJO COBUCI.	
Título: 	Heterosis in the components of lactation curves of Girolando cows.	
Ano de publicação: 	2019	
Fonte/Imprenta: 	Italian Journal of Animal Science, v. 18, n. 1, p. 267-278, 2019.	
DOI: 	https://doi.org/10.1080/1828051X.2018.1507627	
Idioma: 	Inglês	
Conteúdo: 	The objective of this study was to evaluate the effect of heterosis on the lactation curve components of Girolando cattle obtained by fitting different mathematical models. Data consisted of 258,891 test day milk yield records of the first lactation from 37,965 cows of Minas Gerais State (Brazil) between 1998 and 2014. Those cows were from the Holstein breed (H), Gyr breed (G) and six genetic cross-breedings of Holstein × Gyr, (1/4H, 3/4G (1/4H); 3/8H, 5/8G (3/8H); 1/2H, 1/2G (1/2H), 5/8H, 3/8G (5/8H); 3/4H, 1/4G (3/4H); 7/8H, 1/8G (7/8H)), which is officially named as Girolando breed in Brazil. The Wood’s linear model (WDlin), Wood’s non-linear model (WDnlin), Wilmink’s model (WL) and Ali and Schaeffer’s model (ASH) were used for estimating the peak milk yield (PY), time to peak yield (PT), 305-day milk yield (TMY) and four different persistency measures (P, P2:1, P3:1 and P3:2). Regardless of the fitted model, the highest estimates of PY and TMY were for the H group. The heterosis effect was significant (p < .001) for TMY and all components of the lactation curve, except for P2:1. Girolando cattle presented a heterosis effect of 12.30% and 13.03% for PY and TMY, respectively. The magnitude of heterosis effect was larger for PT (24.18%), whereas the different persistency measures presented the smallest magnitude of heterosis values. The producers may use the different genetic groups to benefit from the heterosis mainly for the time to peak, peak yield and 305-day milk yield.HIGHLIGHTS• Girolando cows in production systems in Brazil has shown positive results. • The greater productive efficiency may be because of heterosis on the production.• Thus effect of heterosis on lactation curve can contribute to the improvement of the production system.	
Palavras-Chave: 	Cross-breeding; Persistency of lactation.	
Thesaurus Nal: 	Dairy cows; Mathematical models.	
Categoria do assunto: 	L Ciência Animal e Produtos de Origem Animal	
Registro original: 	Embrapa Gado de Leite (CNPGL)	
Exemplares: 	CNPGL - (24910-1) - UPC - AP - DD -  -  -  - DIS