Comparison of Aspergillus niger phytase and Trichoderma reesei phytase andacid phosphatase on phytate phosphorus availability in pigs fed on maize-soybean meal or barley-soybean meal diets

The efficacy of Aspergillus niger (APhy) phytase, Trichoderma reesei (TPhy) phytase and acid phosphatase (TAcPh) preparations in improving the utiliza tion of phytin-phosphorus in the maize-soybean meal (SBM) or barley-SBM (80 0 : 200 g kg(-1)) diets was studied in two separate digestibility and balan ce trials with ten growing pigs using 5x5 Latin square designs. The positiv e control diet contained a total phosphorus (P) of 6.5 g kg(-1) while the n egative control as well as the APhy, TPhy and TAcPh supplemented diets whic h did not contain additional inorganic-P, had a total P of 4.1 g kg(-1). Th e APhy and TPhy supplements provided phytase activity of 1000 PU g(-1) toge ther with AcPh of 8000 HFU g(-1) TAcPh at a level of 8000 HFU g(-1) was the only addition to one diet. The intrinsic phytase activity of barley was 35 5 PU g(-1) while maize and soybean meal showed no phytase activity. Phytase supplements of the APhy and TPhy sources increased ash digestibility in bo th diets but had only a minor effect on nitrogen utilization. The addition of phytase improved absorption of P by 21%-units in barley-SBM diet and 29% -units in maize-SBM diet, without any difference between the two phytase so urces. The retained P in diets with phytase was higher than in diets withou t phytase, 4.4 (APhy), 4.5 (TPhy) vs. 2.9 g d(-1) in barley-SBM-diets and 3 .7 (APhy), 4.0 (TPhy) vs. 1.8 g d(-1) in maize-SBM-diets. No difference was found between the two sources of phytase. TAcPh without additional phytase did not show any effect on P absorption or retention. Ca absorption and re tention were improved due to the phytase treatments. Supplementing pig diet s with either APhy or TPhy sources seems to be equally effective in enhanci ng the availability of phytate-P. Consequently, these supplements can reduc e the P-excretion of pigs by 32-40% as compared with the diet supplemented with inorganic-P.