| Popis: |
SUMMARY: The aim of this study was to evaluate the effect of enzymes (endo-1,4-β-xylanase [EC 3.2.1.8], endo-1,3(4)-β-glucanase [EC 3.2.1.6], and 6-phytase [EC 3.1.3.26]) in light layer hen diets during the second production cycle (75–95 wk old). Five treatments were used: positive control (PC); negative control 1 (NC1): reduction of dietary nutritional load, as of 100% of the nutritional matrix that the enzymes provide; negative control 2 (NC2): reduction of dietary nutritional load, as of 125% of the nutritional matrix that the enzymes provide; NC1+100% enzymes (NC1–100%): 100% of the matrix, enzymes provide, reformulated and, NC1+125% enzymes (NC2–125%): 125% of the matrix, enzymes provide, reformulated, with 8 replicates and 8 hens for each. Feed intake (P = 0.0059), egg production (P = 0.0096), egg mass (P = 0.0280), feed conversion per egg mass (P = 0.007), and feed conversion per dozen of eggs (P = 0.003) were significantly different with enzyme supplementation. The eggshell weight (P = 0.975), shell thickness (P = 0.920), specific gravity (P = 0.198), and yolk color (P = 0.639) were not affected; however, the relative weights of albumen (P = 0.075) and yolk (P = 0.021) were affected. In conclusion, the use of a multi-carbohydrase complex containing phytase is able to compensate the negative impact of lower nutrient levels, improving the productive performance of layer hens in the second production cycle. |
