Effect of including phytase in diets with reduced metabolizable energy on productive performance, digestibility, and profitability in broiler chickens

Abstract

The increasing demands in broiler nutrition require strategies that enhance both production efficiency and sustainability. The inclusion of exogenous enzymes, such as phytase, is gaining importance for improving nutrient utilization and reducing feed costs. Phytate, the primary form of plant phosphorus, is poorly bioavailable, and birds lack the endogenous phytase necessary for its utilization, which can negatively impact bone and muscle development. This study aimed to evaluate the effects of including phytase in diets with reduced metabolizable energy (ME) on the productive performance, apparent ileal digestibility, and profitability in broiler chickens. A total of 960 broilers were used in the experiment, divided into four groups: a positive control (PC) receiving 1000 FTU/kg of phytase, and three experimental diets (ED1, ED2, ED3) with reductions of −20, −40, and −60 kcal/kg of ME, respectively. During the initiation phase, ED2 exhibited the highest weight gain and the best feed conversion ratio (FCR). Over the entire production cycle, FCR improved linearly (p = 0.0017) with increasing reductions in ME, with ED3 performing the best. Additionally, protein digestibility demonstrated a linear response (p = 0.0189), while ether extract digestibility showed a significant quadratic response at 21 and 42 days (p < 0.011), with optimal digestibility coefficients observed at 2970.8 and 3134.6 kcal/kg, respectively. From an economic perspective, all experimental diets outperformed the control diet in terms of profitability, with ED3 achieving the highest profitability (USD 0.345/bird; +13.1%). The inclusion of phytase in diets with reduced ME not only reduces formulation costs but also maintains productive performance, while enhancing digestive efficiency and economic viability.