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This work aimed to evaluate the influence of postpartum period (precocious - of 28 to 44 days and late - of 45 to 90 days) on the bovine pregnancy rate using fixed-time AI. For that, 678 cows were divided in two groups: precocious group (G-P, n=151) and late group (G-T, n=527). The animals received CIDR® + 2 mL of estradiol benzoate (BE) in the day zero (D0). After eight days (D8) the dispositive was removed and both groups received 2.5mL PGF2α, concurrent with PGF2α injection, they received either 1.5mL of eCG or temporary calf removal (RTB). In the next day (D9), the cows received 1 mL de BE and 24 hours later, the fixed-time AI was performed with Nelore bovine semen. The calves were returned to their mothers. The pregnancy rate was not different between the groups (p>0.05), G-P=40% and G-T=48%. The results indicate that females with less than 45 days of postpartum are able to hormone protocol of fixed-time IA.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:44:16Z No. of bitstreams: 1 S1807-86722013000200015.pdf: 587202 bytes, checksum: a6b1ba5b832eba64eb01b989aee368d1 (MD5) Made available in DSpace on 2013-08-22T18:44:16Z (GMT). No. of bitstreams: 1 S1807-86722013000200015.pdf: 587202 bytes, checksum: a6b1ba5b832eba64eb01b989aee368d1 (MD5) Previous issue date: 2013-06-01 Made available in DSpace on 2013-09-30T18:01:59Z (GMT). No. of bitstreams: 2 S1807-86722013000200015.pdf: 587202 bytes, checksum: a6b1ba5b832eba64eb01b989aee368d1 (MD5) S1807-86722013000200015.pdf.txt: 28524 bytes, checksum: c1341eb8c4878348f4a7c8adef1b14d9 (MD5) Previous issue date: 2013-06-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:18:41Z No. of bitstreams: 2 S1807-86722013000200015.pdf: 587202 bytes, checksum: a6b1ba5b832eba64eb01b989aee368d1 (MD5) S1807-86722013000200015.pdf.txt: 28524 bytes, checksum: c1341eb8c4878348f4a7c8adef1b14d9 (MD5) Made available in DSpace on 2014-05-20T13:18:41Z (GMT). No. of bitstreams: 2 S1807-86722013000200015.pdf: 587202 bytes, checksum: a6b1ba5b832eba64eb01b989aee368d1 (MD5) S1807-86722013000200015.pdf.txt: 28524 bytes, checksum: c1341eb8c4878348f4a7c8adef1b14d9 (MD5) Previous issue date: 2013-06-01 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. Empresa Brasileira de Pesquisa Agropecuária Instituto de Zootecnia Estação Experimental de Sertãozinho Universidade Estadual de São Paulo Faculdade de Ciências Agrárias e Veterinárias Departamento de Zootecnia