EFFECTS OF SUPPLEMENTAL MICROBIAL PHYTASE ON AVAILABILITY OF PHOSPHORUS CONTAINED IN MAIZE, WHEAT AND TRITICALE TO PIGS

Four balance trials were performed, each using four growing pigs initially weighing about 30 kg. Trial 1 was subdivided into three periods: Period 1, 21 days; Period 2, 21 days; Period 3, 15 days. Phosphorus (P) concentration in dry matter (DM) of the pelleted diet was 2.27 g kg-1 in Periods 1 and 3, respectively, and 0.83 g kg-1 in Period 2. Adaptation of faecal P concentration after each change in dietary P concentration was completed within 7 days. Trials 2-4 followed the design of a Latin Square (4 X 4). A basal diet low in P concentration was fed either alone or after blending into test diets containing 60% of maize, wheat or triticale. Each basal and test diet was fed either unsupplemented or after addition of 750 units kg-1 of microbial phytase. All diets were fed unpelleted. Available P (determined as apparent digestible P) of each of the three grains was calculated from differences of results on test and corresponding basal diets. Supplemented microbial phytase increased P availability from 18% to 56% in maize, from 62% to 74% in wheat, and from 52% to 67% in triticale.