2015. Modulation of small intestinal phosphate transporter by dietary supplements of at Pennsylvania State U niversity on M arch 6

ABSTRACT Dietary phosphorus (P) is known as a main modulator of phosphate (Pi) transporter expres-sion. The effect of supplemented mineral P with or without phytase on protein expression of two sodium-dependent Pi (NaPi) transporters and a calcium channel was studied in the small intestine of broilers. Thirty-six broilers were randomly assigned to six differ-ent diets at 15 days of age. Two levels of total P (tP, ad-justed by monocalcium phosphate (MCP) supplemen-tation), 0.39 % (BD−) and 0.47 % (BD+) were fed until day 25; and at each tP level, three levels of phytase were used with 0, 500, and 12,500 FTU/kg of an E.coli phytase. Mucosa samples from jejunum and ileum were taken and apical membranes were isolated by MgCl2 precipitation. Protein expression of NaPi IIb, NaP