Avaliação do sêmen caprino diluído em citrato-gema, resfriado e armazenado a 5ºC por 24 horas

• Ano de defesa: 2006
• Autor(a) principal: Palhão, Miller Pereira
• Orientador(a): Carvalho, Giovanni Ribeiro de
• Banca de defesa: Costa, Eduardo Paulino da , Fonseca, Jeferson Ferreira da
• 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: Sêmen caprino resfriado; Inseminação artificial; Diluidor citrato-gema
• Palavras-chave em Inglês: Cooled goat semen; Artificial insemination; Diluted egg-yolk citrate
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA::REPRODUCAO ANIMAL::INSEMINACAO ARTIFICIAL ANIMAL
• Link de acesso: http://locus.ufv.br/handle/123456789/5717

In Brazil, the dairy goat industry is characterized by a large number of low technology farms, with an average daily milk production per goat of 1 Kg. Semen biotechnologies as artificial insemination (AI) can be an important tool to improve the genetic gain and development of these farms. The use of frozen semen in IA protocols requires a higher level of technology and costs for the farmer when compared with the use of cooled or fresh semen; besides the fertility results from field trials using frozen semen are still doubtful. However the use of fresh semen is restrict to a short period after colleted as the viability of the cells decrease fast at environmental temperatures. Therefore the use of cooled semen in low level technology farms can result in a less-expensive and more efficient tool for multiplying the genetic material in these farms. The aim of this study was to evaluate the fertility in vivo of goat semen cooled and stored at 5˚ Celsius for 24 hours. The experiment was realized in the Goat Research Center of the Animal Science Department/Federal University of Vicosa, Brazil, from May until July (end of the natural breeding season) of 2005. Animals from the Alpine (n=2) and Saanen (n=2) breed were utilized as semen donors and a total of 71 females (lactating goats and young goats) from both breeds were used in the fertility trial. Semen was collected by artificial vagina method, diluted in Ringer Lactate solution and centrifuged at 420 G for 10 minutes. After, the semen pellet was rediluted in Egg-yolk (20% v/v) Citrate extender to achieve a total of 400x106 spermatozoa/ mL. The semen was stored in 0.25 French straws and then used immediately for AI or cooled (average cooling rate = -0.5 ˚C/minute) for 1 hour and stored at 5˚ C for 24 hours before its use for IA. The animals were bred with fresh or cooled semen at 12 hours after the on set of estrus; if the animals continued in estrus for more than 12 hours a second IA was realize at 24 hours after the first insemination. Pregnancy diagnosis was realized by transrectal ultrasonography using a real time B mode scanner with a 5 MHZ linear array transducer. The ultrasonography evaluations were done at day 45 after first IA. The conception rate for young goats (31.2 x 20,0%) and goats (44.4 x 17.6%) did not differ (P>0.05) between fresh or cooled semen, respectively. The total conception rate did not differ (P>0.05) between fresh (38.2%) and cooled (18.9%) semen. The average conception rate of this same herd and period was 28.2%. Historical data from the last four years in the same experimental period and farm showed an average conception rate of 39,9% (109/273). The present study didn't find differences in the conception rates for the semen diluted in Yolk-Citrate with 20% of Egg-Yolk and used to fresh or cold and stored by 24 hours to 5ºC, however, the fertility of the semen cold was below that obtained with controlled breed in the end of the natural reproductive station. Factors climatic, environmental and of handling, besides the quality of the animals, related with the end of the reproductive station, might have contributed to the low fertilities found in the present study.