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Evaluation of three criteria used to identify F-Gene carriers in a romney x merino booroola sheep flock in south Brazil

José Carlos Ferrugem Moraes; Nelson Manzoni de Oliveira; Arturo Selaive-Villarroe

Centro Nacional de Pesquisa de Ovinos, CNPO - EMBRAPA, Caixa Postal 242, 96400 Bagé, RS, Brasil

ABSTRACT

The continuous search for higher fertility in sheep has led to the identification of major genes related to high ovulation rates. Among them, the so called F-gene has been found in a strain of Australian Merino sheep. This gene has been employed in crossing programmes to quickly increase fertility rates. Presently, the identification of F-gene carriers has been made by measuring ovulation rates and/or litter size in ewes, and by progeny tests in rains. In a 3/4 Romney-1/4 Merino Booroola population the precision of criteria employed to screen gene carriers was evaluated. The results showed that although the criteria examined had a satisfactory precision, they disturbed the segregational analysis, highlighting the need for development of improved methods of gene carrier identification.

Keywords: F-gene; Sheep.

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