COMPARATIVE EFFECTS OF ASPERGILLUS-FUMIGATUS AND ASPERGILLUS-NIGER PHYTASES ON PHOSPHORUS AND CALCIUM DIGESTIBILITIES AND PHOSPHORUS FECAL EXCRETION IN THE GROWING PIG

Phytases may ameliorate phytic-P antinutritional properties. The aim o f the present work was to evaluate comparatively the effects of Asperg illus fumigatus (AFP) and A. niger (ANP) phytases included in a growin g pig phytate rich diet (rape seed, maize and barley) at the level of 500 U/kg. The phytic-P rich diet systematically induced hypophosphatae mia, hypercalcaemia and hyperphosphatasaemia. Mean phosphataemia was i ncreased and mean phosphatasaemia and calcaemia were decreased by the ingestion of AFP or ANP. The apparent digestibility of P was significa ntly higher for the AFP diet (52.8%) than for the ANP diet (46.5%) or the control diet (30.8%). The improvement in Ca digestibility by AFP a nd ANP was not statistically significant. AFP and ANP significantly de creased the P concentration in faeces by 33 and 17%, respectively.