YOU CANT GO BY LOOKS FOR SCRAPIE RESISTANCE
ROUGEDE LOUEST
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YOU CANT GO BY LOOKS FOR SCRAPIE RESISTANCE
SELECTING Suffolk sheep for scrapie resistance does not compromise selection for leanness, according to a recent study.
Conducted by the University of Wales-Aberystwyth and MLC, the project compared lean indexes of 300 older breeding animals and lambs from three member flocks of the Suffolk Sire Referencing Scheme. These had varying genetic resistance to scrapie.
Some breeders believe animals with poor scrapie resistance genotypes look and perform better than those with favourable genotypes for scrapie resistance, says MLC sheep scientist Jenny Anderson. "This project tested this theory and shows you cant go by looks."
Of the sheep in the study, 51% were genotype RR, 42% RQ and 7% QQ. Animals with genotype RR and RQ are more resistant to scrapie than QQ animals, but RR animals are favoured for breeding.
When selecting sheep for breeding, the goal of the lean index is to improve weight of lean in carcasses while limiting increase in fat weight. It is calculated from estimated breeding values (EBVs) for scan weight, fat depth and muscle depth.
"There was no evidence of a relationship between scrapie resistance genotype and performance traits in this study. It is, therefore, unlikely that selection for scrapie resistant genotypes will compromise selection for high lean index," says Dr Anderson. *
Selecting Suffolks for scrapie resistance does not compromise leanness,
says Jenny Anderson.