Puberdade de tourinhos da raça Gir concebidos por diferentes técnicas de reprodução

• Ano de defesa: 2010
• Autor(a) principal: Furtado, Sílvia Dantas Costa
• Orientador(a): Mâncio, Antonio Bento
• Banca de defesa: Carvalho, Giovanni Ribeiro de , Veloso, Cristina Mattos
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Zootecnia
• Departamento: Genética e Melhoramento de Animais Domésticos; Nutrição e Alimentação Animal; Pastagens e Forragicul
• País: BR
• Palavras-chave em Português: Puberdade; Tourinhos; Biotécnicas de produção
• Palavras-chave em Inglês: Puberty; Bulls; Biotechnical production
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::PRODUCAO ANIMAL
• Link de acesso: http://locus.ufv.br/handle/123456789/5774

The aim of this study was to determine whether assisted reproductive biotechnologies in vitro fertilization (IVF) and artificial insemination (AI) can interfere on the processes of puberty in young bulls when compared to those generated by natural mating, and measure biometric and seminal parameters of these animals obtained by different techniques applied to animal breeding. There were nine data collections using 189 Gyr animals, ranging in age from one day old to 24 months old. These animals were classified into three categories, according to the reproductive techniques in which they were generated, with groups 1, 2 and 3 were constituted by the animals generated, respectively, from IVF (61 animals), IA (106 animals) and natural mating (22 animals). The animals were raised under pasture conditions with concentrate supplementation and weaned at around 12 months of age. The puberty was determined by means of the physical and morphological characteristics of the semen. There was no significant difference between the three groups regarding age, weight characteristics and testicular biometric during puberty age, demonstrating that the type of biotechnology used in the animal production had no effect on the weight and reproduction development of the same. The young bulls reached puberty at 19.0 ± 2.8 months, weighing 264.0 ± 46.0 kg and 27.4 ± 3.4 cm of scrotal circumference (SC), proving to be sexually late. In this occasion, the groups of animals showed averages and standard deviations of 1.8 ± 1.0 ml for ejaculate volume (VOL), gross motility (TURB) of 0.9 ± 1.0 (0-5), motility (MOT) of 52.3 ± 22.8%, vigor of (VIG) 2.6 ± 0.6 (0-5), sperm concentration in the ejaculate (CONC) of 647.8 ± 858.6 ( x106 spermatozoa), major sperm defects (DMA) of 58.9 ± 31.5%, minor sperm defects (DME) of 13.6 ± 8.3% and total sperm defects (DTotal) of 72.5 ± 34.3 %. It was observed a high and positive correlation between age at puberty (IDPUB), body weight (0.63), IDPUB and PE (0.45), due to the fact that the animals were sexually late. At the age range studied, there was a high correlation between PE and body weight, DM and DTOTAL, and medium to low magnitude with the physical aspects of the semen (MOT, VIG and CONC). Thus, the PE can be used in young animals, as selection criteria for sexual precocity.