Effect of different altitude on reproductive performances and mineral assessment in Ouled Djellal ewes during the mating period.

Abstract

The aim of this study is to evaluate reproductive performances and to reveal the influence of mineral profile on Ouled Djellal ewes reared in different sites during their mating period. Two hundred twenty-six clinically healthy and nonpregnant Ouled Djellal ewes have been used and assigned to four groups according to altitude factor (two plain regions, one tableland region, and one mountain region). In all groups, oestrus was synchronized with ram affect method, and the ewes were naturally inseminated; it was conducted during the month of May for all herds. After 5months of gestation, reproductive parameters were calculated. Concerning the determination of plasma mineral parameters and its influence on reproduction parameters, blood samples were taken from all ewes on the day of introduction of entire rams into all herds. The analyzed variables were fertility, prolificacy, and fecundity, and their overall averages were 78%, 117%, and 92%, respectively, which are well below the averages in flocks reared in intensive mode. However, the lowest rates are recorded at mountain region (Aïn Zaatout) with 65%, 109%, and 71%, respectively. Plasma sodium and potassium were significantly lower in fecundable ewes than in non-fecundable ewes, whereas plasma calcium levels were significantly increased. The region showed in this study a significant influence on all plasma levels of major minerals during mating period. This study made it possible to describe the evolution of some mineral elements in ewes according to whether they are fecundable or not and according to the region (mountain, tableland, plain) during the mating period. This gave us useful information on the impact of plasma minerals levels on reproductive parameters.