Measurement of Ileal and Excreta Endogenous Losses of Phosphorus in Broiler Chickens

Abstract

An experiment was conducted to estimate the ileal and excreta endogenous phosphorus (P) losses in broiler chickens. Three purified diets, namely a P-free diet and a gelatine-based diet containing negligible amount of P and a casein-based diet having 100% available P, were developed. They were offered ad libitum from day 25 to 28 post hatch and ileal digesta were collected. Excreta samples were collected to estimate total tract endogenous losses. The ileal endogenous flow of P in birds fed P-free, gelatin-based and casein-based diets were 25,104 and 438, mg/kg dry matter intake (DMI), respectively. Corresponding values estimated at the excreta level were 830, 560 and 372 mg/kg DM1, respectively. Ileal and excreta endogenous flow of P in birds fed casein-based diet were similar (P>0.05), but ileal flows were lower (P<0.05) than excreta values in birds fed P-free and gelatin-based diets. In conclusion, the present data showed that values determined for endogenous P losses in broiler chickens widely varied depending on the methodology employed.