Estimates of genetic parameters for lifetime reproductive performance traits in Makuie ewes

• Genetic parameters for lifetime reproductive performance traits of Makuie ewes were estimated.
• Direct heritability estimates were low to moderate for lifetime reproductive performance traits.
• Genetic progress of the traits having moderate direct heritability is possible.
• For the low heritable traits the improving of the non-genetic factors can be suggested.

The objective of this study was to estimate genetic parameters for lifetime (over 2–5 years of age) reproductive performance traits in Makuie ewes. The data were extracted from Makuie Sheep Breeding and Raising Station dataset between 1989 and 2015. The studied traits were average of lifetime fertility, fecundity, survival, stay-ability, and total of lifetime female lambs born per ewe joined, female lambs weaned per ewe joined, weight of lambs born, weight of lambs weaned, and pregnancy days. Each trait was fitted by four different animal models, which were differentiated by including or excluding maternal effects. The Akaike information criterion was used to select the most appropriate model for each trait. In addition, series of bivariate animal models were implemented to estimate genetic and phenotypic correlations between traits. Estimates of direct heritability for traits were ranged from 0.00 to 0.15, which indicated that some traits (average fertility, average fecundity, and total weight of lambs born) had low additive genetic basis but others had no or very lower genetic basis. Maternal effects (both genetic and permanent environment) had very little or no effect on the studied traits. Genetic and phenotypic correlations between traits ranged from −0.92 to 0.99 and −0.01 to 0.97, respectively. The results indicated that fertility, fecundity, and total weight of lambs born could be improved by inclusion in the selection index due to their heritability estimation of greater than 0.12. For other traits genetic gain through conventional genetic selection method may be useless in Makuie sheep due to their low heritability estimates. However, these traits could be improved by providing better environment and management techniques.