Superovulation of Mertolenga cows with two FSH preparations (FSH-P and FOLLTROPIN) Superovulação de vacas Mertolengas com duas preparações de FSH (FSH-P e FOLLTROPIN)

Summary: Response to superovulation, fertilization rate, production of viable embryos and fertility subsequent to superovulation were evaluated in Mertolenga cows treated with two follicle stimulating hormone (FSH) preparations of high (FSH-P, n=11) or low (FOLLTROPIN, n=10) LH (luteinizing hormone) activity. Fertilisation rate and production of viable embryos were significantly lower (P<0.001) in FSH-P than in FOLLTROPIN treated cows. Following transfer of fresh embryos to heifers of the same breed (n=25) a 50 % calving rate was obtained. Fertility of donors at the end of a six-month breeding period that followed superovulation was 95 %. These results show that commercial application of embryo transfer is feasible in Mertolenga cattle. Resumo: Em vacas dadoras da raca Mertolenga foram comparadas duas gonadotrofinas com alta (FSH-P, n=11) ou baixa (FOLLTROPIN, n=10) actividade LH (luteinizing hormone), sobre a resposta superovulatoria, a taxa de fertilizacao, a producao de embrioes viaveis e a fertilidade da epoca de cobricao apos o tratamento superovulatorio. A FSH-P induziu uma diminuicao significativa (P<0,001) da taxa de fertilizacao e da producao de embrioes viaveis, quando comparada com a FOLLTROPIN. A taxa de paricao obtida apos transferencia de embrioes a fresco para novilhas receptoras (n=25) da mesma raca (50%) e a fertilidade das dadoras apos a epoca de cobricao subsequente ao tratamento superovulatorio (95%) perspectivam a eficiente aplicacao pratica da tecnologia de transferencia de embrioes na raca Mertolenga.