EFFECT OF BREED, AGE AND FOOD ON REPRODUCTIVE EFFICIENCY OF FEMALE SHEEP OF THE TSIGAI - RUSTY VARIETY PUREBREED AND THEIR CROSS WITH THE SUFFOLK AND GERMAN BLACKFACE.

Fertility, prolificacy and weaning rate were compared for Tsigai - rusty variety (TIRU) purebreed ewes and their Suffolk (50%) × German Blackface (37.5%) x Tsigai - rusty variety (12.5%) (S x BF x TIRU) contemporaries, mated at 8 and 18 months of age. The fecundity, prolificacy and weaning rate for animals mated at 8 months of age and fed in the shelter with hay and corn-barley based concentrate was 78.43%, 105.0% and 78.57% to females from TIRU and 80.0%, 100.0% and 54.17% for animals of the S x BF x TIRU genotype, respectively. For animals of the two breeds mated at 18 months of age and grazing on pastures, the fecundity, prolificacy and weaning rate was 64.71%, 100.0% and 87.88% to females from TIRU and 73.33%, 104.55% and 78.26% for animals of the S x BF x TIRU genotype, respectively. 88.24% females from TIRU and 90.0% from S x BF x TIRU genotype, mated at 8 months, have lambed once up to age of 23-24 months, and 56.86% females from TIRU and 56.66% from the animals from S x BF x TIRU genotype have lambed twice. [ABSTRACT FROM AUTHOR]