Evaluate the effect of a commercial heat stable phytase on broiler performance, tibia ash, and mineral excretion from 1 to 49 days of age assessed using nutrient reduced diets

This study evaluated effects of a novel heat stable phytase on broiler performance, tibia ash, and mineral excretion from 1 to 49 d of age. A total of 1,200 d-old Ross 708 x YPM male broilers were randomly distributed in 40 floor pens assigned to 5 treatments with 8 replicates per treatment. A positive control (PC) was formulated to contain recommended levels of available phosphorus and calcium, whereas the negative control (NC) contained 0.20% less available phosphorus and calcium compared to the PC at each feeding phase. Three treatments containing 500, 1,000, or 2,000 FTU/kg of phytase were added to the NC. Feed intake (FI) and body weight (BW) were determined at 21, 35, and 49 d of age and feed conversion ratio (FCR) was corrected for mortality. On d 21 and 49, left tibiae were collected from 4 birds/pen for ash determination. Feces were collected at 28 and 49 d to evaluate phosphorus, calcium, aluminum, and zinc excretion. Data were analyzed using ANOVA procedures and means separated by Tukey's. Broilers fed with NC + 2,000 FTU/kg had higher BW and FI than broilers fed with NC on d 35 (P < 0.05); however, performance was indistinguishable at d 49. On d 21, broilers fed the NC had lower (P < 0.05) tibia ash compared to the PC and NC + phytase (all levels). Broilers fed NC + phytase (all levels) excreted less minerals compared to the PC (P < 0.05) on d 49. Overall, phytase supplementation improved broiler performance and tibia ash and reduced total mineral excretion.