A study of solely used phytase or in combination with multi-carbohydrase on growth performance along with tibia mineralization, and carcass traits in broilers fed nutrient-deficient diets

Abstract The objective of this study aimed to investigate the effectiveness of phytase alone and in combination with multi-carbohydrase in available phosphorus (AP) and energy-deficient diets on growth performance, nutrient digestibility, tibia traits, and carcass quality of broilers. A total of 288 one-day-old Ross 308 broiler chicks were randomly assigned to one of six dietary treatments in a completely randomized design, with each treatment having 6 replicates and 8 birds per cage. The treatments were as follows: i) positive control with adequate nutrition (PC); ii) 0.20% AP-deficient diet without phytase (NC-1); iii) 0.25% AP-deficient diet without phytase (NC-2); iv) NC-1 diet plus 500 FTU/kg phytase (NCP-1); v) NC-2 diet plus 750 FTU/kg phytase (NCP-2); and vi) NC-2 with 100 kcal/kg ME deficient diet plus 1,000 FTU/kg phytase and multi-carbohydrase: 2,200 U/kg galactomannanase, 30,000 U/kg xylanase, 22,000 U/kg β-glucanase, and 700 U/kg α-galactosidase (NCPM). Broilers in the PC group and those fed enzyme-supplemented diets exhibited greater (P < 0.05) growth performance in terms of body weight (BW), average daily gain (ADG), and feed conversion ratio (FCR), along with enhanced tibia mineralization through the ash, calcium (Ca), phosphorus (P) composition, and tibia breaking strength compared to NC diets throughout the study. Among the treatments, broilers assigned to the NCPM group showed greater (P < 0.05) levels of energy and P digestibility on days 21 and 35. Concerning carcass characteristics, the leg meat yield was greater (P < 0.05) in broilers fed the NCP-2 diet compared to all other treatments on days 21 and 35. Supplementation of phytase at doses of 500 FTU/kg and 750 FTU/kg effectively recovers AP deficiencies of 0.20% and 0.25%, respectively, in broiler diets without compromising the growth performance of broilers. Additionally, combining multi-carbohydrase and phytase led to AP and energy loss recovery, which improved tibia mineralization and nutrient digestibility through their synergistic interaction.