444. Introgression of prolificacy gene in Tunisian Barbarine sheep through marker-assisted selection scheme

Sheep litter size is an important economical and reproduction trait. Tunisian Barbarine sheep 'W-INRAT' provide carrier FecXBar animals, referring to a mutation in the BMP15 gene. This mutation causes increased ovulation rate in heterozygous ewes. The aim of this work was to introgress the FecXBar mutation in two conventional multipliers flocks through the development of a marker-assisted selection scheme. The dissemination of the mutation was conducted by artificial insemination of total 350 conventional ewes during two successive years (2019-2020) by four prolific 'W-INRAT' rams (FecXBar/Y). The F1 offspring were genotyped for FecXBar mutation by allele-specific PCR. For both years, female lambs (n=92) were heterozygous. They were selected and kept as future prolific breeders. Their mattings with conventional rams will serve to increase prolificacy and produce prolific males. This study shows the importance of genotyping at an early age for the selection and management of mattings for an efficient dissemination of the prolificacy mutation.