Effect of Graded Levels of an Enhanced E.coli Phytase with Step-Wise Reduction of Supplemental Inorganic Phosphate on Growth Performance of Broilers Fed Corn-Soy Diet

Abstract

This study evaluated the potential of incremental doses of an enhanced Escherichia coli-derived phytase to support step-wise reduction of supplemental inorganic phosphate in an all-vegetable broiler diet. Corn-soybean meal-based diets containing 0.40/0.80%, 0.35/0.70%, and 0.30/0.60% avP and Ca, respectively from 0-10, 10-25, and 26-42 days posthatch served as experimental control (PC). Three test diets were formulated with 500, 1000, and 1500 FTU/kg of phytase assigned respectively an avP matrix of 0.15, 0.19, and 0.23% and a fixed Ca matrix of 0.15%. An additional diet (PC++) containing extra avP and Ca (+0.05% avP/+0.1% Ca) to that of PC was included to test if avP and Ca were not limiting in PC. Each diet was offered to 16 replicates of straight-run broilers kept in floor pens (30 birds per pen). PC++ had lower (p<0.05; 10 and 25 d) or similar (42 d) BW and toe ash compared with PC confirming the avP and Ca set in PC were sufficient to support optimal growth and bone mineralization. Compared to the PC, diets containing 1000 and 1500 FTU phytase had higher BW (p<0.05) at 10 and 25 d. For the overall period of 0-42 d, FI, BW and FCR did not differ across treatments. Percentage-, but not the absolute-, toe ash at phytase treated groups was significantly (p<0.05) low compared with the PC. The experiment demonstrated that 1500 FTU/kg of enhance E. coli phytase supports optimal BW and FCR of broilers fed corn-soy diet largely void of supplemental inorganic phosphate.

Nutritional cost reduction and increase profitability in commercial broiler production using phytase superdosing

“…In addition, results of studies using different sources of phytase (i.e., bacterial and fungal phytases) in non-ruminant diets observed in the last years were presented in reviews from Adeola and Cowieson (2011), Cowieson et al (2011), andWalk et al (2014). The results of this study showed that broilers fed diets with reduction in the nutritional matrix and supplemented with E. coli 6-phytase presented similar growth performance (Zhou et al, 2008;Poernama et al, 2020) and tibia ash (Zhou et al, 2008) when compared with broilers fed the positive control diet.…”

“…Studies demonstrating dietary inclusion of phytase superdosing in broiler diets with reduction in the nutritional matrix of aP (Pieniazek et al, 2017); aP and Ca (Poernama et al, 2020;Cowieson et al, 2015); aP, Ca, and AME (Ennis et al, 2020), and its combinations with other enzymes in diets with reduction in the nutritional matrix of aP, Ca, AME, and digestible aminoacids (Jlali et al, 2020) have been reported recently with benefits on growth performance and mineral deposition. In addition, results of studies using different sources of phytase (i.e., bacterial and fungal phytases) in non-ruminant diets observed in the last years were presented in reviews from Adeola and Cowieson (2011), Cowieson et al (2011), andWalk et al (2014).…”