Effects of limestone particle size and dietary Ca concentration on apparent P and Ca digestibility in the presence or absence of phytase

ABSTRACT The present study evaluated the effects of limestone particle size and Ca concentration on apparent ileal digestibility (AID) of P and Ca in the presence or absence of a 6-phytase derived from Buttiauxella sp., expressed in Trichoderma. Treatment diets were corn-soybean meal (SBM) based with no added inorganic Ca or P. The design consisted of a factorial arrangement of 2 particle sizes of limestone from the same source (mean particle size: pulverized, PUV