stimates of genetic parameters, principal components and cluster analysis for milk yield and body weight in Guzera cattl

Autor(es)

Monteiro Gama, Manuela Pires ^[1] ; Savegnago, Rodrigo Pelicioni ^[2] ; Ventura, Henrique Torres ^[3] ; Pereira, Mariana Alencar ^[3] ; Freitas, Luara Afonso ^[1] ; Paro Paz, Claudia Cristina ^{[1, 4]} ; El Faro, Lenira ^[4]

Afiliação do(s) autor(es)

^[1] FMRP USP, Dept Genet, Ribeirao Preto, SP - Brazil

^[2] Michigan State Univ, Dept Anim Sci, E Lansing, MI 48824 - USA

^[3] ABCZ, Assoc Brasileira Criadores Zebu, Uberaba, MG - Brazil

^[4] Ctr Avancado Pesquisa Bovinos Corte, Inst Zootecnia, Sertaozinho, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ANIMAL PRODUCTION SCIENCE; v. 62, n. 3 NOV 2021.
• Citações Web of Science: 0

Resumo

Context The estimation of genetic parameters for traits related to the production of milk, beef or both may assist in defining the selection criteria and objectives of the breeding program, as well as in the identification and selection of genetically superior animals. Aims The objectives of this study were to estimate genetic parameters for body weight and 305-day milk yield of Guzera cattle and to perform cluster analysis on the basis of estimated breeding values for these traits, to identify groups of animals that could be selected for the production of beef, milk or dual purpose. Methods Body weights (N = 253 012) of males and females were ecorded at 120 days of age (BW120), at weaning (WW), at 365 days (BW365), at yearling stage (YW) and at 24 months (BW24), and 6237 complete lactations (MY305) of 4723 cows were used to estimate the genetic parameters. The bi-trait animal models included direct additive genetic, maternal permanent environmental and temporary random effects for body weights and additive genetic, permanent environmental and temporary environmental random effects for MY305. The fixed effects for all the traits were contemporary group and age of cow at calving. Key results The estimates of heritability ranged from 0.14 +/- 0.01 for WW to 0.23 +/- 0.01 for MY305. The genetic correlations between body weights at different ages and milk yield were positive and ranged from 0.27 +/- 0.11 to 0.38 +/- 0.19. Two principal components explained 86.74% of the total genetic variance among the traits. Conclusions Cluster analysis identified four different clusters and showed that the Guzera breed had bulls with different genetic patterns that permits genetic selection for beef, milk or dual purpose. Implications The genetic correlations of the present study suggest that selection to increase milk yield will lead to a slight genetic gain in the same direction for body weight at different ages, in contrast to reports from some other studies. (AU)

• Processo FAPESP: 18/01540-2 - Predição dos valores genômicos utilizando modelos Bayesianos e de redes neurais para características de resistência a endoparasitas em ovinos Santa Inês
• Beneficiário: Luara Afonso de Freitas Januário
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 13/20091-0 - Predição de valores genéticos em populações experimentais de camundongos utilizando genotipagem seletiva
• Beneficiário: Rodrigo Pelicioni Savegnago
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado