PHYTATE CONTENT OF EXCRETA AND PHYTATE RETENTION IN THE GASTROINTESTINAL-TRACT OF YOUNG CHICKENS

A HPLC procedure was used to determine inositol phosphate in chicken d roppings and intestinal content. When compared with the classical ferr ic chloride method of determining total inositol phosphate in excreta, the HPLC method gave higher values, but the linear relationship betwe en values determined by the two methods was significant (r = .82, P < .014). Holding fecal samples at room temperature (22 C) from 0 to 32 h before analysis for inositol phosphates had no effect on the concentr ation of inositol hexaphosphate, and, although there were significant effects on inositol pentaphosphate, the results were difficult to inte rpret. The results indicated very little hydrolysis of inositol phosph ate in the excreta of these chickens as they lay on a dropping tray. E xcreta from 3-wk-old birds contained significantly less inositol penta phosphate than excreta from 2-wk-old birds. The excreta from birds rec eiving a diet containing .27% nonphytate phosphorus contained less ino sitol pentaphosphate than those receiving a diet containing .42% nonph ytate phosphorus. The chromic oxide indicator method seemed to be feas ible for determining total phytate disappearance (retention). It was n ot satisfactory for determining retention in various sections of the g astrointestinal tract, because there seemed to be dilution of phytate and disappearance of chromic oxide in the crop and gizzard in the chic ken. There was a marked increase in the concentration of inositol hexa phosphate and to a lesser extent inositol pentaphosphate in the small intestine and cloaca as the other nutrients in the diet were digested.