Nutrition Inadequacies of Grazing Sheep in Semiaricl Regions and Planning Supplement for their Minimal Discomfort with Integration to Environment

A temperature humidity index (THI) in the range of 75 to 91 during summer causes environmental stress in semiarid regions. Average THI of 87 and 84 during summer and rainy season indicated stress on grazing sheep, however, it was comfortable during winter season. Significant difference in grazed herbage amongst weaner lambs, yearlings and adult sheep existed and its relative feed quality and value was more in growing than in adult sheep. A wide difference in the deficiency of dry matter (DM), digestible crude protein (DCP) and metabolizable energy (ME) indicated that the sheep grazed preferentially to meet the protein requirement and little extent for energy but not for DM. DM and DCP intake was deficit (%) by 13 and 8 in lambs, 1 and 34 in yearlings and, 258 and 4, in adult sheep, respectively. Environmental discomfort was integrated with nutrition deficiency and minimal total discomfort was drawn with a concentrate supplement (CS) having 12% DCP and 12 MJ/kg. As per the simulation of actual pasture intakes in the minimal total discomfort model, weaner lambs require CS @ 100 or 150 g/d to stipulate recommended daily weight gain (DWG) of 100 and 150 g and, yearling sheep require @ 100, 300,400 g/d to stipulate recommended DWG of 100,150 and 200 g/d. Mature sheep require 75 or 100 g/d CS for maintenance for minimal total discomfort. On an average, 40 kg OM, 250 g N and 1 kg inorganic nutrients per growing and non productive adult sheep flock per season were essential to replenish pasture lands.