Abstract
The effect of graded levels of exogenous xylanase (XYL) at 0, 1500, 2000 or 2500 xylanase units (XU/kg) in laying hen diet containing 300 g/kg wheat distillers dried grains with solubles (DDGS) was examined. A total of 72, twenty-two-week-old, Hy-Line Brown laying hens were allocated to 24 cages, three birds in a cage. Each diet was fed for nine days to six cages following randomisation. Supplementing diets with 2500 XU, the highest XYL level, increased (p<0.05) dietary apparent metabolisable energy (AME) and nitrogen corrected AME (AMEn) in a linear pattern (L<0.05), and nitrogen retention coefficient (p<0.05) following quadratic response (Q<0.05). For every 100 XU, dietary AME and AMEn increased by 0.013 MJ and 0.012 MJ, respectively. There were no differences observed in bird growth or egg production variables. Further research is warranted to study the impact of greater XYL activities in laying hen diets formulated to contain greater DDGS inclusion rates.