Haematology, blood biochemistry and tissue histopathology of lambs maintained on diets containing an insect controlling protein (Cry1Ac) in Bt-cottonseed.

This experiment assessed the effect of feeding genetically modified cottonseed (Bt) containing an insect controlling protein (Cry1Ac) on haematology, blood biochemistry and histopathology of lambs. Haemato-biochemicals were estimated at periodic intervals, and histopathology at termination of experiment. Thirty three weaner lambs were fed a composite feed mixture (CFM) ad libitum individually, in three groups for 123 days. The isonitrogenous CFM had roughage (Perl Millet Stover) and concentrate ratio of 350:650. Diet fed to control lambs contained groundnut oil meal as protein source while other two groups received diet containing either whole cottonseed (N-Bt) or Bt-cottonseed (Bt-CS). Daily feed intake and average daily gain were similar among lambs of three groups. Lambs fed N-Bt diet had higher (p < 0.05) serum protein and globulin compared to control and Bt diets, while albumin content was higher (p = 0.018) in Bt diet fed lambs. Serum urea and creatinin content, alkaline phosphatase (ALP) and serum glutamate pyruvic transaminase (SGPT) activities were not different among lamb groups, while urea and creatinin content and ALP activities increased linearly (p < 0.001) with increased feeding period. Blood haemoglobin (Hb), haematocrit (Hc), white blood cells (WBC), mean corpuscular volume (MCV) and mean corpuscular haemoglobin concentration (MCHC) ranged from 11.1% to 11.2%, 31.8% to 32.8%, 7.0 to 8.3 (× 10(3) /μl), 19.1 to 22.5 fl and 33.2% to 35.5%, respectively, were similar among lamb groups. Erythrocyte sedimentation rate (ESR) (p = 0.008) and red blood cell counts (p = 0.006) were higher in Bt diet fed lambs. Control and N-Bt diet fed lambs had mild fatty infiltration in liver and/or micro-calculi in renal cortex, and such lesions were not seen in Bt diet fed lambs. Growth, haemato-biochemical and histopathology did not change by Bt-CS feeding in growing lamb. However, before recommending the use of Bt-CS in routine feed formulations prolonged feeding experiments of Bt-cotton seed require.