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The objectives of this study were to evaluate systematic factors that influence longevity and to estimate the heritability of functional longevity by survival analysis of Suffolk sheep in the Czech Republic. A total of 20,502 ewes from 137 flocks were used. The longevity of Suffolk ewes was influenced to some extent by their average prolificacy. The effects of growth intensity and the development of muscularity and fattiness, as well as the effect of the prion protein gene PrP haplotype on the risk of the exclusion of the ewe from breeding were relatively low. Heritability estimates were h2 = 0.438 for the length of production life in days (LPL), h2 = 0.098 for the number of litters of the ewe during her lifetime (NL), h2 = 0.111 for the total number of lambs born (TLB), and h2 = 0.103 for the total number of labs weaned (TLW). Correlations between the breeding values for LPL and NL, TLB or TLW were high. Therefore, these indicators of the ewe’s lifelong production, which are more desirable and understandable for sheep breeders, should be used in indirect selection for longevity.. |
