Two-stage in vitro digestibility assay, a tool for formulating non-starch polysaccharide degrading enzyme combinations for commonly used feed ingredients of poultry rations

Abstract

Aim: An attempt was made to assess the effect of pure enzyme combinations with the objective of formulating customized enzyme mixtures based on sugar release when subjected to two-stage in vitro digestion assay. Materials and Methods: A two-stage in vitro digestibility assay was carried out for commonly used feed ingredients for poultry viz., maize, soy bean meal, sunflower cake, and de-oiled rice bran supplemented with three concentrations of xylanase (5000; 7500 and 10000 IU/kg), cellulase (50; 100 and 400 IU/kg) and aβ-D-glucanase (100; 200 and 400 IU/kg) were used to formulate various NSP enzymes combinations. In total 27 NSP enzyme combinations (3×3×3) were formulated and the sugar released due to NSP digestion was quantified by phenol sulphuric acid method. Results: The total sugar release was significantly (P<0.05) higher with supplementation of various enzymes combinations for maize, sunflower cake and de-oiled rice bran where as no significant (P<0.05) interaction of various NSP enzymes combinations was observed for soy bean meal. The NSP digestibility was highest in combination (×ylanase-5000, cellulase-50 and aβ-D-glucanase-400 IU/kg), (xylanase-10000, cellulase-50 and aβ-D-glucanase-200 IU/kg) and (xylanase-7500, cellulase- 100 and aβ-D-glucanase-100 IU/kg) for maize, sunflower cake and de-oiled rice bran respectively. In case of sunflower cake, significant (P<0.01) three way interaction was observed among the xylanase, cellulose, and aβ-D-glucanase enzymes and the two-way interactions between the enzymes were also significant (P<0.01). Conclusion: It is concluded that 'n' number of non-starch Polysaccharide enzymes combinations can be screened for their efficiency to digest non-starch Polysaccharides present in various feed ingredients commonly used in poultry rations by employing two-stage in vitro digestibility assay as a tool.