Influence of adaptation length on assayed metabolizable energy of maize and barley supplemented with or without glucanase for broiler chickens using the index method

Abstract Background This effect of adaptation length (AL) on the apparent metabolizable energy (AME) and nitrogen‐corrected AME (AMEn) of maize and barley supplemented with or without β‐glucanase enzyme was assessed in this study. Three experimental diets were formulated with a wheat‐soybean meal diet as a reference diet (RD) and two additional diets with maize or barley included at 300 g kg−1 into the reference diet. A total of 324 Cobb 500 broilers were used for the experiment in a 3 × 2 factorial with factors AL (10, 7, or 4 days) and enzyme (with or without) for cereal grains maize and barley. Birds on 10, 7, or 4 days AL were given experimental diets beginning at from d 11, 14, and 17 of age, respectively. Excreta were collected on d 20 and 21. The AME and AMEn of cereal grain were calculated by the difference method. Results There was no significant interaction between the factors for barley AME and AMEn. The AME and AMEn of maize decreased p < 0.05) step‐wise with increasing in AL from 4 to 10 days. However, when supplemented with an enzyme, the AME and AMEn of maize were similar at 4, 7, and 10 days AL. Enzyme supplementation improved (p < 0.01) AME and AMEn of barley, but there was no effect of AL on barley AME and AMEn. Conclusion In conclusion, the influence of AL on assayed AME in cereal grains supplemented with enzyme was more pronounced for maize and less so for barley.