Abstract

The aim of study was to investigate the effect of different types of roughage (hay, green and silage) and yeast added to the barley grain on the productive performance of the Barki ewes during the gestation and suckling periods. Eighty-four Barki ewes, 3-4 years of age and 42.93±0.19 kg of average body weight, were randomly assigned to six groups (14 ewes in each) before the mating season. A factorial design was used for 3 x 2 treatments based on Berseem hay (BH), and either fresh Atriplex halimus (FA) or silage (AS) in the absence (Y-) or presence (Y+) of 5g/ewe/day of the dry yeast. All ewe groups recorded gain in their live body weight (LBW) during early and late gestation period. The highest loss in LBW was recorded for BH and Y+ during the suckling period. The AS was the highest consumed roughage followed by BH and then FA during the gestation and suckling periods. The addition of yeast (Y+) resulted a reduction of roughage intake than control one (Y-) during both gestation stages but the total milk yield (TMY) was significantly higher for BH followed by FA and AS. Also, Y+ significantly increased (P<0.05) the TMY (423) compared to Y- (384) treatment. Milk fat content was not affected by roughages type, yeast addition or their interaction. However, milk protein content was significantly higher for BH (5.14) than the other types of roughage. Silage (AS) was better than other roughages in conversion efficiency to milk and also Y+ was better than Y-. Yeast addition to ewes diets increased birth weight of their lambs compared to un-supplemented one (Y-). It could be concluded that weaning weight relative to that in hay group was 93.6 and 80.4 for AS and FA, respectively. Generally, adding yeast to different roughage diets during suckling period led to a significant increase in weaning weight. Furthermore, the economic efficiency (EE) was higher (P<0.05) in both FA and AS compared to BH. Also, yeast addition (Y+) resulted in higher EE (P<0.05) in compared to Y-. © 2021. All Rights Reserved.