Sites of phytase and xylanase activities in the gastrointestinal tract of broiler chickens

Abstract

Because digesta vary in pH in different gastrointestinal segments of poultry, exogenous phytase or xylanase may exhibit differences in activity along the gastrointestinal tract. Previous reports indicated that the stomach is the major site of exogenous microbial phytase activity, with no further activity found in the small intestine of piglets. Information regarding exogenous phytase or xylanase activity in the gastrointestinal tract of poultry is largely unavailable. Because exogenous phytase or xylanase activity in the digesta is extremely low, normal phytase or xylanase activity measurements are prone to errors resulting from background interference contributed by the exogenous inorganic phosphate or xylose in the digesta (Walsh et al., 1995). The aim of this study was to utilize electrophoresis activity stain to detect the activity of phytase or xylanase in different gastrointestinal segments of broiler chickens fed diets containing exogenous enzymes.