Abstract

DEKHILI, M.. Phenotypic and genetic parameters for ewe reproductive performances of Ouled-Djellal breed (Algeria). Arch. zootec. [online]. 2014, vol.63, n.242, pp.269-275. ISSN 1885-4494.  https://dx.doi.org/10.4321/S0004-05922014000200005.

Reproductive traits from 318 Ouled-Djellal ewes were recorded from 2008 to 2010. Genetic parameters were estimated for three basic and two composite traits. The basic traits were fertility, prolificacy and rate of survival. The composite traits were lamb weaned per ewe joined and weight of lamb per ewe joined. Year, age, parity and mating month, were considered as fixed effects. Direct genetic effects, permanent environmental effects of ewe were considered to be random effects. A derivative-free algorithm was used to obtain REML estimates of genetic environmental parameters. Estimates of herita-bilities for animal genetic effects were mainly small, due to the typical high influence of environmental factors on reproductive traits and to non-normal distribution of traits.

Keywords : Direct genetic effect; Heritability; Maternal genetic effect; Permanent environmental effect; Repeatability.

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