Breed and selection line differences in the temperament of beef cattle
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Data
2013-06-01
Autores
Piovezan, Ubiratan
Cyrillo, Joslaine Noely dos Santos Gonçalves
Costa, Mateus José Rodrigues Paranhos da [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Editora da Universidade Estadual de Maringá (EDUEM)
Resumo
O temperamento de quatro raças bovinas foi avaliado utilizando-se o teste de velocidade de fuga (FT) e o escore de comportamento (BST). FT foi definida como o tempo necessário para animais percorrerem uma distância de 2 m após a pesagem. BST foi baseada no comportamento dos animais na balança, amostrando-se quatro categorias de comportamento: movimentos, intensidade de respiração, vocalizações e coices. Os coeficientes de herdabilidade de FT e BST foram estimados com uso de um modelo de máxima verossimilhança restrita, considerando meio irmãos paternos. Caracu apresentou menores médias para BST do que as demais raças. Nelore apresentou resultados intermediários, seguida por Guzerat e Gyr com médias mais elevadas (p < 0,05). Resultados similares foram observados para FT, mas as médias de Caracu e Nelore não diferiram entre si. Observou-se baixa associação entre FT e BST (r p= -0,36; p < 0,01). A correlação entre rank de touros ordenados pelos seus valores preditos (p) para FT e BST foi moderada e negativa (r s = -0,63; p < 0,001). A herdabilidade de FT e BST foi de 0,35 e 0,34, respectivamente. A comparação de rebanhos Nelore com diferentes critérios de seleção para peso corporal mostrou que linhas de seleção podem modular positivamente o temperamento de Bos indicus.
The temperament of four beef cattle breeds were measured using a flight time test (FT) and a behavior score test (BST). FT was defined as the time taken by animals to cross a distance of 2 m after weight scale. The BST used a visual assessment of cattle behavior in which the results of four categories defined the score: movements, breathing intensity, vocalization and kicking. FT and BST coefficients of heritability were estimated using the restricted maximum likelihood, considering half siblings. Caracu presented a lower BST value than the other breeds. Nellore presented intermediate results, followed by Guzerat and Gyr with similar and higher means (p < 0.05). Similar results were observed with FT, but Caracu and Nellore did not differ from each other. A low association between FT and BST was found (r p= -0.36; p < 0.01). The correlation between a sire's ranking, according to the predicted breeding values (p) estimated for FT and BST, was moderate and negative (r s= -0.63; p < 0.001). Heritability estimates for FT and BST were 0.35 and 0.34, respectively. Inside Nellore breed, herds with different selection criteria for weight were compared. Our results show that selection line based on weight might positively modulate temperament of Bos indicus cattle.
The temperament of four beef cattle breeds were measured using a flight time test (FT) and a behavior score test (BST). FT was defined as the time taken by animals to cross a distance of 2 m after weight scale. The BST used a visual assessment of cattle behavior in which the results of four categories defined the score: movements, breathing intensity, vocalization and kicking. FT and BST coefficients of heritability were estimated using the restricted maximum likelihood, considering half siblings. Caracu presented a lower BST value than the other breeds. Nellore presented intermediate results, followed by Guzerat and Gyr with similar and higher means (p < 0.05). Similar results were observed with FT, but Caracu and Nellore did not differ from each other. A low association between FT and BST was found (r p= -0.36; p < 0.01). The correlation between a sire's ranking, according to the predicted breeding values (p) estimated for FT and BST, was moderate and negative (r s= -0.63; p < 0.001). Heritability estimates for FT and BST were 0.35 and 0.34, respectively. Inside Nellore breed, herds with different selection criteria for weight were compared. Our results show that selection line based on weight might positively modulate temperament of Bos indicus cattle.
Descrição
Palavras-chave
beef cows, Behavior, Fear, husbandry, vacas de corte, Comportamento, Medo, manejo
Como citar
Acta Scientiarum. Animal Sciences. Editora da Universidade Estadual de Maringá (UEM) - EDUEM, v. 35, n. 2, p. 207-212, 2013.