Sensitivity of broiler starters to three doses of an enzyme cocktail in maize-based diets

International audience; 1. The aim of the present study was to investigate the effect of an enzyme cocktail composed of xylanase, amylase and protease on the performance and nutrient utilisation of broiler starters fed a maize-based diet. A maize/soy-based control diet was formulated to be marginal in apparent metabolisable energy (AME) and amino acids and this diet was fed without or with two concentrations (250 and 500 g/tonne) of the exogenous enzyme cocktail. 2. The growth performance was measured over a 21d period after which ileal contents were collected for measurement of digestible energy, nitrogen and dry matter. Excreta were collected from day 17 to 20 post-hatch and used to determine the AME and, retention of nitrogen and dry matter. 3. Supplementation of the control diet with 250 and 500g/ tonne of the enzyme cocktail resulted in enhanced performance of the chicks (1.4% and 8.3% respectively for weight gain and, 1.2% and 2.2% respectively for feed per gain), but the improvements were significant (P < 0.05) only at 500g/ tonne. 4. Addition of both 250 and 500g/tonne improved (P < 0.05) the AME, nitrogen-corrected AME and dry matter retention compared with the control though the improvements were of a greater magnitude with the higher dose. These effects were also reflected in the apparent ileal digestibility coefficients of dry matter, nitrogen and energy, with 500g/tonne of the enzyme cocktail improving (P < 0.05) ileal digestible energy by 3.4%. 5. These data demonstrate that a cocktail of exogenous enzymes containing xylanase, amylase and protease is effective in improving the performance of broiler chicks fed a maize-soybean meal based diet. However, these benefits may be dose-dependent and so an economic analysis involving ingredient and enzyme pricing and the relative performance and digestibility enhancements could allow the end user to select the most economical dose to maximise return on investment.