Evaluating the Efficacy of a Novel Consensus Bacterial 6-Phytase Variant on Broiler Performance

Abstract

Improvements in P and Ca availability that can be achieved with exogenous phytase have been extensively studied and are well accepted for poultry. However, there is currently loss acceptance of matrix values for digestible AA and ME, despite increasing evidence of extra-phosphoric effects. Given the increased pressure to reduce feed costs and maximize feed utilization, there remains considerable interest in developing more efficacious phytases and to optimize their application. Therefore, through 4 experiments the objective of this research was to evaluate the efficacy of a novel consensus bacterial 6-phytase variant on broiler growth performance. In Experiment 1, phytase compensated for the nutrient and energy down-specifications applied at each dose-level and maintained growth performance, bone quality, and carcass characteristics equivalent to those of a nutritionally adequate diet through 63 days of age. This could be beneficial for producers interested in producing larger and higher yielding birds to meet the demands for further-processed poultry products. In Experiment 2, there was a dose-dependent effect of phytase on the growth performance, bone quality, and carcass characteristics of broilers fed diets highly deficient in nutrients and energy through 42 days of age. A phytase dose of 2000 FTU/kg may be needed to thoroughly degrade phytate in the GIT, more effectively eliminating the anti-nutritional effects of phytate, and resulting in increased nutrient availability. In Experiment 3, phytase compensated for the nutrient deficiency in the basal diets, and improved growth performance and bone quality of broilers fed diets containing three levels of phytate-P (0.25, 0.29, and 0.33%) through 42 days of age, regardless of phytate-P levels. Increasing phytase dose from 500 to 1,500 or 3,000 FTU/kg further improved feed efficiency and this could lead to production benefit. In Experiment 4, phytase compensated for the reduction in nutrients and energy at each dose-level and maintained growth performance, bone quality, and carcass characteristics of broilers fed US type diets through 42 days of age. Diets can vary depending on region or ingredient availability, even in corn and soybean meal-based diets with inherently low phytate-P and alternative feed ingredients, there is sufficient substrate for phytase to act upon. Overall findings of this research validated the use of dose-dependent AA and ME matrix values in addition to P and Ca down-specifications in phytase supplemented diets cost-effectively maintained broiler growth performance, bone quality, and carcass characteristics equivalent to those of a nutritionally adequate diet. The implications of these findings are not only limited to better and confident nutrient efficiency or increased profitability, but also increased sustainability in broiler production. Full nutrient and energy matrix values based on the contributions of phytase can be applied with confidence.