Comparative Performance of Goats and Sheep Fed on High-fiber Pelleted Diets Supplemented with Different Nitrogen Sources

Growth performance of indigenous sheep fed Sporobolus virginicus grass hay grown in saline desert lands and irrigated with high salt content ground water

Twenty-eight indigenous ewe lambs (6 months of age and 14.4 kg body weight (BW)) were used to evaluate the effect of feeding Sporobolus grass hay (SGH) as the only source of forage on growth, and feed and water intakes. The ewe lambs were randomly and equally allocated to two treatment groups (14 lambs/group). The ewe lambs in group 1 (treatment 1) received SGH, while lambs in group 2 (treatment 2) received Rhodes grass hay (RGH) as the only source of forage. Water was available at all times for both treatment groups. Sporobolus grass was irrigated with brackish water of high salt content (20,000 ppm) and grown in saline desert lands (sabkha) in the United Arab Emirates. The average daily dry matter intake was significantly (P < .05) higher for the animals fed SGH than those fed RGH at all stages. Both water intakes per unit body gain and water intake per unit feed intake were significant (P < .05) between the two treatments group at all stages. Average daily gain did not differ significantly (P > .05) between the two groups at all stages. From these data, we conclude that SGH can replace Rhodes hay in sheep diet without significant effect on sheep performance.

Effects of dietary energy density on feed intake, body weight gain and carcass chemical composition of Omani growing lambs

Forty male Omani lambs were used in a feeding trial to study the effects of feeding diets containing various levels of metabolizable energy (ME) on growth and carcass composition. Ten lambs were selected randomly and slaughtered at the start of the trial to provide information on initial carcass composition. Thirty lambs were divided randomly into three groups and fed three diets varying in ME concentration (low, medium and high) from weaning (at average 76 days) until slaughter at the mean weight of 30kg. Digestibility of dry matter (DM) was 66.9, 68.7 and 73.9% for low, medium and high energy diets, respectively. Apparent gross energy digestibility was 66.8, 67.2 and 73.3% corresponding to dietary concentrations of 12.2, 12.6 and 13.9MJ of DE/kg for low, medium and high energy diets, respectively. Daily DM intake ranged between 3.12 and 3.73 % of body weight (BW) which was equivalent to 76.5-97.5g/kg(0.75) or 0.738-1.142MJ ME/kg(0.75). Daily BW gain increased (P<0.001) with increasing ME density with a maximum of 154g/day observed in lambs on high energy diet during the last 4 weeks of the experiment. Feed conversion ratio (FCR), i.e., kg feed/kg BW, improved with increasing ME density (P<0.001). Sheep fed high energy diet had heavier BW (P<0.01), empty BW weight (P<0.001), carcass weight (P<0.01) higher dressing percentage (P<0.05) but lower gut content (P<0.001) than lambs fed medium and low energy diets. Sheep slaughtered at the end had lower water, protein but higher carcass and non-carcass chemical fat than sheep slaughtered at the start of the experiment. This study indicated that meat production from sheep in Oman will be improved in form of higher BW gains and better carcass composition by increasing energy levels in the diet.