Effect of dietary supplementation with arginine on haematological indices, serum chemistry, carcass yield, gut microflora, and lymphoid organs of growing turkeys

A 8-wk feeding experiment was conducted to investigate the effect of dietary supplementation with Arg on haematological indices, serum chemistry, carcass yield, gut microflora, and lymphoid organ weights of growing turkeys. A total of one hundred and eighty 56-d-old male grower turkeys were weighed individually and randomly assigned to 1 of 3 dietary treatments with 6 replicate pens, and 10 turkeys per pen in a completely randomized design. Dietary treatments consisted of basal diets supplemented with 0, 0.5, and 1.0 g Arg/kg. Haematological indices and serum chemistry were measured at 84 and 112 d of study. Carcass yield, relative weights of retail cuts, organ weights, and gut microflora were measured at d 112. Except eosinophil, no effect of Arg supplementation was obtained on haematological indices at d 84. At d 112, finisher turkeys fed the diet supplemented with 0.5 g Arg/kg had the greatest red blood cell (quadratic, P<0.001), lymphocyte (linear, P=0.011; quadratic, P<0.001), and basophil counts (quadratic, P<0.001). In grower turkeys at d 84, total serum protein (quadratic, P=0.030), and serum globulin concentrations (quadratic, P=0.043) increased initially as Arg supplementation increased from 0 to 0.5 g/kg, but decreased with the 1.0 g Arg/kg. Uric acid concentration and alanine aminotransferase activity reduced as Arg supplementation increased from 0 to 0.5 g/kg, but increased with the 1.0 g Arg/kg (quadratic, P=0.002). In finisher turkeys at d 112, total serum protein (linear, P=0.004; quadratic, P=0.002), serum globulin (linear, P=0.008; quadratic, P=0.030), serum albumin (linear, P=0.012; quadratic, P=0.040), and triodosterine concentrations (linear, P=0.025; quadratic, P=0.033) increased with increasing Arg supplementation. At d 112, spleen weights increased linearly (P=0.006), while thymus weights increased quadratically (P=0.003) with increasing dietary Arg supplementation. Salmonella counts in the small intestinal content of turkeys at d 112 reduced quadratically as Arg supplementation increased from 0 to 1.0 g/kg (P=0.029). In conclusion, Arg supplementation increased packed cell volume of finisher turkeys, improved serum chemistry of grower, and finisher turkeys as indicated by increased total serum protein, and reduced serum enzymes with appreciable improvement obtained when included at 0.5 g Arg/kg. Arginine supplementation enhanced the relative weights of thymus, spleen, and reduced Salmonella counts in small intestine of turkeys.