The present study was conducted to determine the effect of replacement of DL-methionine (DL-M) by graded levels of herbal methionine (HM) on nutrient digestibility and blood parameters of broiler (Cobb strain). Two hundred forty day old unsexed broiler chicks were procured, weighed and randomly divided into five dietary treatments (C, T1, T2, T3 and T4 having 0, 25, 50, 75 and 100% replacement of DL-M with HM, respectively; n=48) and there were twelve birds in each replicate. The diets formulated were iso-caloric and iso-nitrogenous. The feeding trial was conducted for a period of 6 weeks and a metabolism trial was conducted for four consecutive days after 28 days of feeding trial. At the end of trial eight birds per replicate were slaughtered to study blood biochemical parameters. The results revealed no adverse effect on nutrient digestibility and nitrogen retention among different dietary groups. Also no adverse effect of HM supplementation on blood biochemical parameters and cell mediated immune response among different dietary groups were found. It was concluded that dietary replacement of DL methionine with variable levels of herbal methionine does not impart any beneficial effect.
Key words: Broilers, DL-methionine, Herbal methionine