Abstract
An experiment was conducted with twenty crossbred male lambs to assess the effect of cotton (Gossypium) seed meal (CSM) on blood constituents and immunity. Lambs were randomly assigned to a reference diet (30% deoiled peanut meal, DPNM) and four test diets containing 40% of either raw, 45 minutes cooked, 1% $Ca(OH)_2$ and iron (1 free gossy-pol, FG : 0.3 Fe) treated CSM (replacing approximately 50%, reference concentrate mixture). These isonitrogenous and isocaloric concentrate mixtures were fed to meet 80% of protein requirements (NRC, 1985) along with ad lib maize hay for 180 days. Blood was collected at 60, 120 and 180 days post feeding. The lambs were sensitized with Brucella abortus S99 antigen after 140 days and were subjected to ELISA and delayed type hypersensitivity. Blood haemoglobin, erythrocyte count, leucocyte count, total protein, total albumin, total globulin, urea, creatinine concentration and aspartate aminotransferase activity in lambs fed on raw or processed CSM were comparable to the values of reference lambs. The higher (p<0.01) blood glucose levels observed in CSM fed lambs at 60 days of feeding was latter reduced to the levels comparable with those on reference diet at 120 and 180 days of feeding. The alanine amino transferase activity was lower in lambs fed raw and cooked CSM containing diets at 120 and 180 days of feeding. A marginal increase in serum iron and alkaline posphatase activity was observed in iron treated group and raw CSM fed lambs, respectively. The humoral immune response and DTH reactivity was lower (p<0.05) in lambs fed raw CSM (consuming 302.83 mg FG/day). Cooking, $Ca(OH)_2$ and iron treatment of raw CSM showed a positive response in alleviating the suppression of immune response owing to the reduced consumption of FG by 40.19, 17.40% and 26.73%, respectively in these diets. The present study thus indicated that consumption of 40% raw CSM (302.83 mg FG/day) though did not affect majority of the haematological and blood biochemical parameters, but markedly suppressed the immune mechanism of lambs.