Heritability of some productive traits in animals from Ile de france sheep breed.

The purpose of the present study was to determine the heritability of some productive traitsin sheep of Ile de France breed. The study was conducted with 369 ewes and 473 lambs of Ile de France breed for the period 2016-2020, bred at the Experimental Base of the Institute of Animal Science -- Kostinbrod. Biological fecundity was determined as the ratio of the litter size, stillbirths and aborted lambs to the number of lambed ewes. Live weights were measured at birth, at 10 days, at 30 days and at 70 days, with a deviation of ± 2 days. The information was processed using the methods of variational statistics. A variance analysis was performed using NOVA model, significance of the effect of the factor was determined by the values of Fisher's F-criterion, and the significance of the differences between the studied groups -- by the Student's t-test, with the statistical software Data Analysis, Excel 2021, Microsoft. The coefficients of the heritability of the studied productive traits were estimated. A significant effect of the year of lambing F = 2.725* on biological fecundity and the year of birth on the live weight at birth F = 5.721***, at 10 days F = 23.875***, at 30 days F = 14.363*** and at 70 days of age F = 44.715*** was found. The average fecundity of the ewes was 154%. There were statistically significant differences for the average live weight of lambs at different stages of development depending on the year of birth. Estimated heritability values for biological fecundity h²-0,03* and live weight at birth h²-0.05***, at 10 days h²-0.18***, at 30 days h²-0.12***, and at 70 days of age h²-0.30*** were from low to average. [ABSTRACT FROM AUTHOR]