Nutrient Intake and Utilization by Range Managed Sheep in Critical Physiological Stages Maintained on Grazing with Concentrate Supplementation in a Hot Semi-Arid Environment

The reported study was conducted on range managed Malpura ewes that were non-breeding empty, were at an advanced stage of pregnancy, and were in early lactation, under a protocol of free grazing with concentrate supplementation at 1.00, 1.25 and 1.50% of their body weight to assess their plane of nutrition and nutrient intake. The biomass yield of pasture plots was 1689, 1820 and 2912 kg/ha in pregnancy, lactation and empty phases, respectively. In addition to natural shrubs and forbs, Cenchrus ciliaris (36.4%) and dead litter (31.6%) were the major component of pasture vegetation during pregnancy. The dead litter disappeared during the lactation and empty phase with a concomitant increase in distribution of Cenchrus ciliaris to 73.0 and 87.2% respectively. The daily dry matter consumption from supplemental concentrate and free grazing was 70.1, 57.3 and 63.5 g/kg $W^{0.75}/d$ with concentrate to roughage ratio of 40:60, 47:53 and 33:67 in pregnancy, lactation and empty phases respectively. Digestibility of DM and OM were similar in the three phases while CP digestibility was higher (p<0.0l) during lactation than other two phases. Digestibility of NDF, ADF and cellulose were higher (p<0.0l) in empty than pregnancy and lactation, while hemicellulose digestibility was similar in lactation and empty and lower in pregnancy phase. The ewes in ~hases of pregnancy, lactation and empty consumed 7.1, 7.7 and 6.1 g DCP and 197.2, 214.6 and 232.5 kcal DE/kg $W^{0.75}/d$ respectively. It is concluded that ewes maintained on semi-arid Cenchrus dominated pasture with concentrate supplementation during pregnancy, lactation and empty phases consumed 45.2, 45.1 and 35.2 g DCP/Mcal ME respectively.