Effects of dietary microbial phytase supplementation on the digestibility of calcium and phosphorus and growth performance of broilers
2008
Lumbo, N.B., Philippines Univ. Los Baños, College, Laguna (Philippines)
Experiment was conducted to determine the effect of phytase supplementation on the calcium and phosphorus digestability and growth performance of broilers. The study involved 500 chicks randomly distributed to five treatments following a completely randomized design (CRD). The five treatments consisted of the Control diet (T1), diet 2 (less 0.1% AvP and less 50 and 100 kcal ME/kg feed at starter and finisher, respectively) (T2), Diet 2 with phytase A (T3; Diet 2 with Phytase B (T4) and Diet 2 with Phytase C(T5). Reduction of ME [Metabolizable energy] and P significantly improved both the ileal fecal coefficient of digestibility of calcium but not under protein, phosphorus and energy. Birds fed Diet 2 had significantly lower tibia bone and calcium but comparable phosphorus levels with the control. Phytase supplementation of Diet 2 did not improve mineral content of tibia bone of broilers but resulted to reduction of fecal P excretion. There were no significant differences observed on the body weight, body weight gain, and feed consumption of broilers among treatments. Birds fed Diet 2 had the poorest feed utilization at 28 days of age. Phytase A supplementation of Diet 2 improved the feed efficiency of broilers. However, there was no significant difference on feed efficiency at 41 days of age. Supplementation of Diet 2 with Phytase A generated the highest improvement in IOFCC [income over feed and chick cost] but not as high a those fed the control diet.
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