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The influence of the prolificacy gene Fec B on the reproductive biology of 3/4 Romney Marsh x 1/4 Merino Booroola ewes

C.J.H. Souza L.M.^I; Chagas^I; J.C.F. Moraes^II

^IFaculdade de Veterinária, UFRGS, Porto Alegre, RS, Brasil
^IIEmpresa Brasileira de Pesquisa Agropecuária, Centro de Pesquisa de Pecuária dos Campos Sul Brasileiros, 96400-970 Bagé, RS, Brasil. Send correspondence to J.C.F.M.

ABSTRACT

Some aspects of estrous were evaluated during the reproductive season in 72 3/4 Romney Marsh x 1/4 Merino Booroola ewes. Daily distribution of onset of estrous, length of estrous and incidence of anovulatory cycles for carrier and non carrier females of the prolificacy gene FecB was studied. For these parameters the genotypes were statistically similar. Ovulation rate was greater in FecB gene carriers than in non carriers. This shows that the Fec gene acts mainly on the ovulation rate, without changing aspects of estrous behavior.

Keywords: gene Fec B; reproductive biology; Romney Marsh; Merino Booroola ewes.

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