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
Joseph P. Gulizia, Martha Rueda, Fozol K. Ovi, Susan M. Bonilla, Rishi Prasad, Mark Jackson, Omar Gutiérrez, Wilmer J. Pacheco
Abstract
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.