Résumé:
In the present study, we tried to improve the growth and reproduction performances in our sheep breeds, through a cross between Ouled Djellal ewes and D'men males according to the alternative cross model.
The results obtained concerning the growth parameters of the lambs, show that there is a significant improvement; both for mean birth weight at weaning and for growth rate.
We obtained a mean birth weight of 3.34 kg, which is significantly higher than the average weight of Ouled Djellal (3.91 kg) and D'men (2.5 kg).
The same applies to the average weight at weaning; we obtained an average weight of 14.27kg which is slightly lower than that of the parents, in fact, the weaning weight respectively in the Ouled Djellal breed and the D'men race is: 15.35 kg and 17.1kg.
The GMQs obtained are higher than those of the D'men race and slightly lower compared to the GMQs of the Ouled Djellal. The GMQ obtained from 0-21 days was 181g / d, thus significantly improving growth rates.
According to the results obtained, the characters studied show a superiority over the D'men population, which makes it possible to say that the F3 have really benefited from the complementarity of the genetic cross for the growth traits.
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As for the reproduction parameters, in our test we obtained: A fertility rate of 88% which is comparable to that of the two breeds studied;
A fertility rate of 140% which is lower than that of the D'men race, but significantly higher than the fecundity of the Ouled Djellal breed.
A prolificity rate of 140%: higher than that of the Ouled Djellal breed and close to that of the D'man breed, so a very striking heterosis effect.
Summing up, the alternative cross between the Ouled Djellal and D'man breeds gives rise to a very high prolificity rate compared to the Oueld Djellal breed, which remains to improve the level of milk production.
