The Effect of a Mixed-Enzyme Product in Broiler Diets on Metabolizable Energy, Phosphorus and Calcium Retention

The importance of enzymes in the poultry industry is ever increasing because they help to extract as many nutrients as possible from the raw material available and reduce environmental impacts. Therefore, an experiment was conducted to examine the effect of a natural enzyme complex (ASC) on diets low in AME, Ca and P. Ross 308 broilers (n = 900) were fed one of four diets: (1) positive control (PC) with no enzyme added (AME 12.55 MJ/kg, AVPhos 4.8 g/kg and AVCal 9.6 g/kg); (2) negative control (NC) with no enzyme added and down-specified for AME, Ca and P (AME 12.18 MJ/kg, AVPhos 3.3 g/kg, AVCal 8.1 g/kg); (3) negative control plus ASC at 200 g/t; and (4) negative control plus ASC at 400 g/t. Broiler performance, digesta viscosity, tibia mineralization and mineral content were analyzed at d 21. Between d 18 and 20, excreted DM, GE, total nitrogen, Ca, and P were analyzed. ASC at 200 g/t and 400 g/t improved the FCR (p = 0.0014) significantly when compared with that of the NC. There were no significant differences in BW or FI between the treatments. Birds fed ASC at 200 g/t and 400 g/t had significantly improved digesta viscosity (p < 0.0001) compared with that of the PC and NC and had significantly higher excreted DM digestibility (p < 0.01) than the NC and the PC with 400 g/t ASC. ASC inclusion significantly improved P retention (p < 0.0001) compared with that in the PC. Ca retention was significantly increased by 400 g/t ASC compared with that in the PC and NC (p < 0.001). AME was significantly higher (p < 0.0001) for all treatments compared with that in the NC. There were no significant differences between treatments for any of the bone measurements. This study showed that feeding ASC can support the performance of broilers when fed a specification reduced in Ca, P and AME, with the greatest results being seen with the higher inclusion level of ASC.