Growth dynamics and altitude effect on growth performance of Ouled Djellal lambs during the pre-weaning period

Abstract. This study evaluates the growth dynamics and the effect of altitude on different growth phases of pre-weaned Ouled Djellal lambs in northeastern Algeria. Forty-nine lambs born in the spring to multiparous ewes were weighed, and their average daily gain was calculated at different ages (at birth, D 30, 60, 90 and 120). The results show that maximum growth occurs during the lamb’s first month of life at 200 g/day. Highly positive and significant correlations were recorded between D 90 and D 120 (0.94), D 60 and D 120 (0.88), D 60 and D 90 (0.87) and D 30 and D 90 (0.77). Concerning the altitude effect, lambs born in low altitude regions show a better growth performance than lambs born in high altitude regions, with a significant difference (P0.05) noticed for D 90 and D 120, which confirms that the Ouled Djellal breed is a typical breed of the steppe and the high plains.