Quantification of nutritional sustenance and microbial protein production of sheep during different physiological stages in semi-arid regions

Abstract

Female lambs, yearlings, pregnant and lactating ewes, 24 each, were randomly divided into 2 equal groups of 12 each. All groups were fed guar straw as basal roughage without (control, CG) and with (experimental, EG) concentrate supplement (CS) consisted 18% total CP and 18 MJ/kg of gross energy. CS offered @25 g/kg W0.75. DM intake was recorded daily and compared with the recommendations of ARC (1998). Metabolism trial was conducted during each physiological stage. CS intake was 20 to 25 g/kg W0.75 with an increase of 1 to 2 g/kg W0.75 with age. DM, N and energy were deficient without CS during all physiological stages. Although CS provided deficit nutrients, efficiency of their utilization was far below the standards (ARC 1998). Purine derivatives excreted in the urine of adult sheep was lesser than lambs or yearlings and ascertained their inverse relationship with body size. Inefficiency in microbial protein production (MBP) without CS, ranged between 25 and 50% compared to optimum production of 30 g/kg apparently digested organic matter in rumen. Performance output index (POI) calculated as function of efficiency indicated 60 to 70% below global standards of optimum performance when fed on guar straw alone. CS increased the POI by 5 and 35% more than optimum level in lambs and pregnant ewes. Performance of yearlings and lactating ewes on CS needed 14 and 50% more improvement to make it comparable with standards.