Broiler feed formulated with phosphorus, calcium, and energy deficiencies supplemented with exogenous enzymes

Abstract

Three experiments were carried out to verify the effects of the enzyme phytase, alone or combined with an enzyme complex, in diets deficient in available phosphorus (AP), calcium (Ca), and metabolizable energy (ME) on broiler performance, ME, and dietary amino acid digestibility. A total of 1,538 male Cobb 500 broilers were allocated to the three experiments, each of which consisted of five treatments: positive control (PC; basal ration); negative control 1 (NC1; PC minus 0.15% of AP, 0.16% of Ca, and 68 kcal kg-1 ME); negative control 2 (NC2; PC minus 0.15% of AP, 0.16% of Ca, and 101 kcal kg-1 of ME); NC1 plus phytase; and NC2 plus phytase plus enzymatic complex. Body weight gain (WG) and feed intake were measured from 1-21 days and from 1-42 days, and the corrected feed conversion rate (FCR) for mortality was calculated. In the second and third experiments, the apparent ME corrected for nitrogen balance (AMEn) and standardized digestibility of amino acids, respectively, were determined, for the diets supplemented with phytase and the enzymatic complex. In the first experiment, enzyme supplementation increased (p < 0.05) WG at 21 days and 42 days relative to the negative controls. Phytase inclusion improved (p < 0.05) FCR at the initial phase compared to the NC1 diet. In the second experiment, enzyme supplementation did not affect (p > 0.05) AMEn. In the third experiment, both enzyme treatments improved (p < 0.05) the digestibility of amino acids in the supplemented diets compared to the deficient diets. Supplementation with phytase and carbohydrases preserves the performance of broilers fed diets deficient in AP, Ca, and ME and improves amino acid digestibility.