Fatores que influenciam a inseminação artificial em ovinos (Ovis aries) da raça Serra da Estrela
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2017
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Resumo
A inseminação artificial é um método de reprodução assistida em que uma vez obtido
o sémen, o mesmo pode ser aplicado num momento posterior no sistema reprodutor da
fêmea, com o auxílio de instrumentos especializados. Esta técnica tem vindo a crescer de
importância em explorações leiteiras de ovinos, devido à necessidade de melhoramento
genético exigida pela industrialização dos produtos lácteos. Assim, os proprietários dos
rebanhos Serra da Estrela foram obrigados a aumentar as produções diárias de leite e, para
isso, contam com o auxílio da Associação Nacional de Criadores de Ovinos da Serra da
Estrela (ANCOSE) que, através dos seus machos melhoradores da raça beneficiam
inúmeras fêmeas, de onde nascem altas produtoras leiteiras.
O presente trabalho foi realizado com o intuito de avaliar a eficácia da inseminação
artificial em efetivos da raça Serra da Estrela expostos a diferentes fatores nomeadamente o
stresse causado pela tosquia, a idade da ovelha, o macho utilizado, a cor da lã, o número de
partos e a exploração de origem. Foi através do acompanhamento do trabalho realizado
pelo médico veterinário responsável da ANCOSE que me foi permitido obter todos os dados
necessários. Os resultados obtidos auxiliarão não só na restruturação de novas estratégias,
mas também aumentando a segurança das que já estão estipuladas, com o intuito de
aumentar o sucesso da inseminação artificial e do melhoramento da raça Serra da Estrela.
Como seria de esperar, o fator exploração teve um papel importantíssimo no decorrer
sucesso da inseminação artificial. Por outro lado, todos os restantes fatores não se
mostraram relevantes para o sucesso da inseminação artificial, dentro dos valores testados,
o que quer dizer que não foi a variação destas que determinaram que as ovelhas
inseminadas parissem um maior número de nados vivos. Os fatores não determinantes
foram a idade das ovelhas, a data da tosquia, a cor da lã, a hora que se procedeu à
inseminação e o macho utilizado. Todos estes parâmetros eram alvo de questões não só
pelos responsáveis do melhoramento da raça, mas também pelos proprietários dos
rebanhos, a quem se trouxe alguma novas informações e maior segurança para trabalhos futuros.
Artificial insemination is a method of assisted reproduction that consists in obtaining male semen to subsequently introduce in the female reproductive system with the aid of specialized instrumentation. This technique has great importance in dairy farms due to the interest in genetic improvement that is required by the industrialization of dairy products. Therefore, the owners of the herds in Serra da Estrela were forced to increase the daily production of milk and they relied on the help of ANCOSE that through their improved male breeders allowed many females to be born with high genetic merit for milk yield. This work was performed in order to evaluate the effectiveness of artificial insemination done in herds in Serra da Estrela exposed to different factors including stress caused by shearing, the age of the sheep, the male used, the color of wool, the number of previous births and the farm. It was by following the work of the responsible veterinarian of ANCOSE that allowed me to get all the data that was required to get these results. The results obtained are going to help not only the restructuring of new strategies, but also guarantee that the current ones are well established, in order to increase the success of artificial insemination in breeding Serra da Estrela sheep. As one would expect, the farm factor had an important role in this investigation. On the other hand, all the other factors were not relevant for the success of the artificial insemination, which means that it was not the variation of these that determined that the inseminated sheep came to term, with live lambs. The factors which were not determinant were the age of the sheep, the date of shearing, the wool color, the time of insemination and the male used. All these parameters were questioned not only by breeders, but also by the owners of the herd which gave them some reassurance for the future.
Artificial insemination is a method of assisted reproduction that consists in obtaining male semen to subsequently introduce in the female reproductive system with the aid of specialized instrumentation. This technique has great importance in dairy farms due to the interest in genetic improvement that is required by the industrialization of dairy products. Therefore, the owners of the herds in Serra da Estrela were forced to increase the daily production of milk and they relied on the help of ANCOSE that through their improved male breeders allowed many females to be born with high genetic merit for milk yield. This work was performed in order to evaluate the effectiveness of artificial insemination done in herds in Serra da Estrela exposed to different factors including stress caused by shearing, the age of the sheep, the male used, the color of wool, the number of previous births and the farm. It was by following the work of the responsible veterinarian of ANCOSE that allowed me to get all the data that was required to get these results. The results obtained are going to help not only the restructuring of new strategies, but also guarantee that the current ones are well established, in order to increase the success of artificial insemination in breeding Serra da Estrela sheep. As one would expect, the farm factor had an important role in this investigation. On the other hand, all the other factors were not relevant for the success of the artificial insemination, which means that it was not the variation of these that determined that the inseminated sheep came to term, with live lambs. The factors which were not determinant were the age of the sheep, the date of shearing, the wool color, the time of insemination and the male used. All these parameters were questioned not only by breeders, but also by the owners of the herd which gave them some reassurance for the future.
Descrição
Dissertação de Mestrado Integrado em Medicina Veterinária
Palavras-chave
Técnicas de reprodução assistida , Inseminação artificial , Desempenho reprodutivo , Raça ovino Serra da Estrela