Genetic correlations between visual slaughter conformation scores and growth and reproductive traits in Canchim cattle.
We obtained heritability and (co)variance component estimates for slaughter conformation scores at 420 days of age (SCS420), age at calving (first, AFC; second, ASC), calving occurrence until 38 months of age (CP38), weight at 420 days of age (W420), and scrotal circumference at 420 days (SC420) in Canchim (5/8 Charolais + 3/8 Zebu) cattle. A total of 23,168 records of Canchim animals, including 12,493 females and 10,675 males, were analyzed. SCS420 indicated carcass structure, muscle development, and subcutaneous fat deposition. The slaughter conformation score of each animal was relative to the whole contemporary group; 1 corresponded to the lowest expression of the trait and 6 to the highest. Heritabilities, and genetic and residual correlation estimates between SCS420 and reproductive and weight traits, were estimated by multitrait analyses using an animal model with Bayesian inference, employing a linear model for AFC, ASC, SC420, and W420 and a threshold model for CP38 and SCS420. Heritability estimates for SCS420, AFC, ASC, CP38, W420, and SC420 were 0.11, 0.15, 0.15, 0.15, 0.30, and 0.30, respectively. Genetic correlation estimates between SCS420 and the other traits were 0.08 (AFC), 0.58 (ASC), 0.08 (CP38), 0.43 (W420), and 0.17 (SC420). Visual slaughter conformation scores respond to individual selection and can be used as selection criteria in Canchim cattle. Selection to improve sexual precocity would not be effective in improving carcass conformation and composition, and selection for animals with high breeding values for yearling weight may improve slaughter conformation at the yearling stage.
Universidade Federal do Rio Grande do Norte, Unidade Acadêmica Especializada em Ciências Agrárias, Distrito de Jundiaí, Macaíba, RN, Brasil.
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Borba
Universidade Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, Departamento de Zootecnia, Jaboticabal, SP, Brasil.
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Baldi
Universidade Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, Departamento de Zootecnia, Jaboticabal, SP, Brasil.
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Feitosa
Embrapa Gado de Corte, Campo Grande, MS, Brasil.
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da Silva
Universidade de São Paulo, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Nutrição e Produção Animal, Pirassununga, SP, Brasil.
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Pereira
Embrapa Pecuária Sudeste, São Carlos, SP, Brasil.
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Alencar
D000003:Abattoirs; D000367:Age Factors; D000818:Animals; D001499:Bayes Theorem; D001835:Body Weight / Q000235:genetics*; D001947:Breeding; D002417:Cattle; D005260:Female; D016014:Linear Models; D008297:Male; D010641:Phenotype; D012098:Reproduction / Q000235:genetics*; D012741:Sexual Maturation / Q000235:genetics