Breeding and exploitation of prolific breeds in Czechoslovakia

In the years 1971—1979 many experiments were conducted in order to elucidate problems of meat production increase in sheep. Ewes of native breeds (Mutton Merino = M, Improved Wallachian = I) were mated to rams of prolific breeds (Finnsheep = F, Romanov = R), producing F1 crossbred females. The crossbred ewes were mated to rams of a third mutton breed (Texel, Dorset Down, M) to produce meat lambs. In experiments from 1980 to 1987on the basis of the I and the R and F crossbred combinations were produced to provide contemporary comparison of purebreds, F1, F2 and backcrosses, both to I and to F and R. The purebred and crossbred populations were analysed for the estimation of crossbreeding parameters necessary for the optimization of the formation of a synthetic dam breed. The reproduction characters which were analysed were fertility, prolificacy, mortality rate, litter size (born and weaned) and milk production. From the wool production characters the greasy wool production, clean wool production and mean fibre diameter were of interest. From the production characters the following were analysed: birth, weaning and slaughter weights, daily gain from birth to weaning or slaughter, carcass weight and other carcass value traits