Effect of strategic supplementation with multi-nutrient urea molasses blocks on body weight and body condition score of Lohi sheep owned by tenants of Pakistan

Abstract

The effect of strategic supplementation with multi-nutrient urea molasses blocks (MNUMB) on BW and body condition score (BCS) in Lohi ewes (treated, n = 514) during late gestation and lactation was compared with those (control, n = 391) grazing on only post-harvest crop residues and road side in the irrigated district of Okara in central Punjab (Pakistan). Analysis of variance revealed highly significant ( P < 0.01) differences in body weight (BW) and body condition score (BCS) of ewes of various ages with different reproductive status and seasons under both flocks. Analysis of variance also revealed a significant interaction ( P < 0.05) between reproductive status and seasons in favor of BCS. Ewes aged 48 months in average constituted the highest (34.5% and 35.6%), whereas those aged 60 months had the smallest (10% and 4%) proportion in the control as well as in the treated flock. Mean BW and BCS in ewes of control flock was 33.5 and 2.08 kg, and lower ( P < 0.05) than 35.0 and 2.31 in ewes in the treated flock, respectively. Ewes aging 12, 24 and 36 months treated with strategic supplementation of MNUMBs were not only heavier ( P < 0.01) but also had highest BCS of 2.34. Lactating ewes constituted highest proportion (39%, 51%) followed by pregnant (35%, 32%) ewes in both flocks, respectively. Proportion of dry (16%) and freshly conceived (9.5%) ewes tended to be higher in the control than in the treated flock. BW was 8–11% higher ( P < 0.01) in pregnant than in lactating or dry ewes in both flocks with similar BCS. Seasons of autumn and summer were found to affect BW more ( P < 0.01) than BCS. Pregnant ewes in treated flocks had gained highest BW, 10–12% higher than ewes under control ( P < 0.01) or than non-pregnant ewes ( P < 0.05) but lost at a rate of 5–6% at lambing. BW in lactating ewes in treated flock was higher ( P < 0.01) than ewes in control. Lambs suckling ewes with strategic supplementation of MNUMBs grew at a faster rate (122 g/day) with 10–15% higher survival rate than those (97 g/day) in the control flock during lactation of 16 weeks but non-significantly. Based on this improvement it can be concluded that supplementation with appropriate sources of energy and N exerts desirable effects on the traits of economic importance in sheep.