Níveis de proteína e fósforo em rações com fitase para frangos de corte, na fase de 14 a 21 dias de idade: 2. valores energéticos e digestibilidade de nutrientes

摘要: A digestibility assay was carried out to determine the apparent metabolizable energy values (AMEn), dry matter coefficients (DMDC), excretion and retention coefficient of phosphorus (P), nitrogen (N), calcium (Ca), potassium (K), copper (Cu) zinc (Zn), using 250 Cobb male broiler chickens receiving treatments distributed in a factorial schedule 3 ´ + 1 (available level - 0.25; 0.34 0.45% crude protein [CP]- 15.0; 17.0 19.0% control diet, with normal nutritional levels), five replicates birds each. In diets reduced levels available (aP), 500 FTU phytase were added requirement 17%. Except for treatment, all formulated on digestible amino acids basis. The energetic 15.0 17.0% CP, independently aP used or supplementation, presented higher AMEn that diet possibility regarding supplemental addition. DMDC CP different than diet. reduction associated lower enzyme supplementation allowed reduce minerals excretion, which showed better coefficients, except Zinc However, as relatively compared minimized when supplemented phytase. manipulation could mainly nitrogen, P Cu, minimizing environment pollution caused by these elements.