Performance, energy increment and digestibility of nutrients in broiler chickens diets containing exogenous enzymes

Author(s)

Paula Wick Rizzoli

• Document type: Master's Dissertation
• Press: Pirassununga.
• Institution: Universidade de São Paulo (USP). Faculdade de Zootecnica e Engenharia de Alimentos (FZE/BT)
• Defense date: 2009-10-16

Examining board members

Douglas Emygdio de Faria; Jacinta Diva Ferrugem Gomes; Jose Otávio Berti Sorbara

• Advisor: Douglas Emygdio de Faria

Abstract

This study evaluated the effect of supplementation of two enzymatic complexes on performance, energy increment and digestibility of dry matter (DM), crude protein (CP), amino acids (AA) and ether extract (EE) by three methodologies (total excreta collection, collection with marker and ileal collection) in broilers diets. In the performance assay a total of 2,592 male broiler chicks were randomly distributed in seven treatments (1: positive control; 2: negative control 1 (NC 1) with 2% reduction on apparent metabolizable energy (AME), AA and CP from 1 to 21 days and 2,5% from 22 to 42 days; 3: negatice control 2 (CN 2) with 4% reduction on AME, AA and CP from 1 to 21 days and 5% from 22 to 42 days; 4: NC 1 with 400 ppm of enzymatic complex A (α-amylase and β-glucanase); 5: NC 1 with 500 ppm of enzymatic complex B (α-amylase, β-glucanase and xylanase); 6: NC 2 with 400 ppm of enzymatic complex A; 7: NC 2 with 500 ppm of enzymatic complex B. Treatment one had six replicates and all the others treatments had seven replicates, in a total of 48 experimental units of 54 birds each. A feeding program with two phases was used from 1 to 21 days and from 22 to 42 days. Body weight gain, feed intake, feed conversion rate, adjusted feed conversion rate, viability and index of production efficiency were measured. In the metabolism assay a total of 351 male broiler chicks were housed in metallic batteries and randomly distributed in the same treatments of the performance assay. Treatments 1, 2 and 3 had 5 replicates and all the others treatments had 6 replicates, in a total of 39 experimental units of 9 birds by cage. The enzymatic complex B in the diet with lower reduction reached the same level of performance as the positive control diet. In the first collection of the metabolism assay (21 days), the enzymatic complexes were not efficient to increment the energy of the feed and digestibility of DM, EE, CP and AA. In the collection with 42 days, the treatment 5 provided the best result for digestible and metabolizable energies, but was not different of the treatments 1, 3 and 4 in total excreta collection methodology and of the treatments 3 and 4 in collection with marker and ileal collection methodologies. Treatment 5 even provided higher digestibility of DM by collection with marker methodology. The enzymatic complexes improved the ether extract digestibility when compared to their respective control treatments. The treatments 4 and 5 presented higher crude protein digestibility by ileal collection. The highest coefficients of digestibility of AA were observed in treatment 5, followed by treatment 4. In general, the total excreta collection methodology promoted higher consistency of the results. It was concluded that the exogenous enzymes utilization is technical and economically feasible. (AU)

• FAPESP's process: 07/01965-9 - Effect of enzymatic complexes use on performance and increase of feed energy in broilers
• Grantee: Paula Wick Rizzoli
• Support Opportunities: Scholarships in Brazil - Master