Effects of Superdose Phytase and Acidifier Supplementation in a Phosphorus-Deficient Diet on Growth Performance, Carcass Characteristics, Cecal Microbiota, and Intestinal and Liver Morphology in Broiler Chickens

This study evaluated the effects of super dose phytase and acidifier supplementation in a phosphorus-deficient diet on growth performance, carcass characteristics, cecal microflora, and intestinal and liver morphology in broiler chickens. A total of 400 one-day-old male broiler chickens of the Ross 308 strain was used in a completely randomized design, with 5 dietary treatments and 4 replications, each containing 20 birds. The treatments were as follows: 1. Control (basal diet without additives); 2. Control + Phytase: (PHY; 2000 FTU/kg); 3. Control + acidifier (ACI; 3 gr/ kg); Control + phytase + acidifier (PHAC; 2000 FTU/kg + 3 g/kg); and 5. Low-phosphorus diet + phytase + acidifier (LPHAC; 2000 FTU/kg + 3 g/kg). The study assessed daily weight gain (DWG), daily feed intake (DFI), Feed conversion Ratio (FCR), live body weight (LBW), carcass characteristics, tibia morphometric and mechanical traits, cecal microbial populations, and jejunal and hepatic histomorphology. Broilers fed PHAC showed higher DWG, improved FCR, and greater LBW during the starter period (1–10 d), while LPHAC increased DWG in the grower phase (11–24 d) and resulted in the highest overall DWG over 1–42 d compared with ACI (P < 0.05).The relative weight of the gastrointestinal tract (GIT) was significantly higher in birds fed with ACI diet compared to those receiving PHY (P < 0.05). Additionally, villus height (VH) was significantly greater in broilers fed with ACI diet than in those receiving either with LPHAC or PHY diets (P < 0.05). Crypt depth (CD) was significantly increased in broilers fed with LPHAC diet compared to those receiving the control diet (P < 0.05). Overall, combined supplementation of phytase (2000 FTU/kg) and acidifier (3 g/kg) improved growth performance, whereas dietary inclusion of 3 g/kg acidifier enhanced intestinal morphology by increasing villus height and width under reduced-phosphorus conditions. These findings suggest that phytase and acidifier supplementation may support early intestinal development and mineral utilization without inducing adverse hepatic histomorphological changes or altering cecal microbial populations in broiler chickens.