Genetic variability of fleece shedding in the martinik hair, romane sheep breeds and their crossbreds
Résumé
From the ancestral pelage of the domestic sheep which looks like the protective double coat of the wild sheep, changes following domestication and the development of textile industry resulted in the development of the modern woolled sheep with a large decrease in the tendency to moult and extension of wool fibre at the expense of coarse hair leading to a single coat where all fibres are similar in dimension and grow permanently. Wool production is still the main purpose of sheep farming in the southern hemisphere, but in Europe wool production is often unprofitable and there is an interest in the use of breeds that have no wool or shed their wool due to the relative value of meat and wool, and increasing shearing costs. In the present paper investigations were made to evaluate genetic variability of moulting or fleece shedding including QTL detection in the French Romane, the Martinik Hair, a hairy sheep without wool close to Barbados-Black-Belly and a Martinik Hair-Romane backcross population. In the Romane breed, 43.2% of adult ewes shed at least part of their fleece once a year during spring. Heritability estimate of moulting aptitude is high (0.46) but prevalence of total fleece shedding is low (1.5% of ewes shed all their fleece). In the Martinik Hair-Romane backcross population 72% of animals shed their fleece. It was proposed to introgress gene pool from the Martinik Hair in the Romane breed through an experimental design combining QTL detection and introgression of QTL for fleece shedding in the Romane breed.