Genetic parameters of productive traits in Mouton Charollais sheep

Staika Laleva, Petya Slavova, Georgi Kalaydzhiev, Yovka Popova, Stanimira Slavova, Nikolai Ivanov, Daniela Miteva

Abstract: The aim of the present study is to establish the heritability, repeatability and genetic correlations of
the main productive traits – fecundity and live weight, in Mouton Charolais sheep.
The object of study is the sheep flock bred at the Agricultural Institute in Stara Zagora, including
498 female animals for the period 2005–2018. Phenotypic values and heritability of the traits live
weight at birth and weaning, at 9 and 18 months, and at 2.5 years, have been established. Fecundity
(number of lambs born per ewe) is reported for the entire study period. The correlations between selection
traits are also calculated and analyzed.
The regularities of the general genetic model have been applied:
Y = G + E and G = а + d + е.
The statistical model used is based on the „Animal model” and is as follows:
Yijklmnop = HYMi + Breedj + Agek + SLl + LSm + Sexn + LWo + GTp + eijĸlmnop
The calculated values of heritability, repeatability and correlations in Mouton Charolais sheep are
an indicator of low genetic diversity, constriction of the genetic determination of productive traits in
the flock and and the need of individual selection for each of them.
The obtained results are due to the long-term purposeful selection activities and the more significant
influence of the environmental factors, which implies low efficiency of the mass selection by
phenotype.

Keywords: genetic parameters; Mouton Charolais; productivity; sheep

Date published: 2021-12-22