Effects of xylanase supplementation of corn-soybean meal-dried distiller's grain diets on performance, metabolizable energy, and body composition when fed to first-cycle laying hens

The increased cost of energy for laying hen diets has resulted in the use of enzymes, such as xylanase, to increase energy digestibility and thereby reduce the need for dietary energy. A 24-wk-long experiment was conducted using 432 twenty-week-old Hy-line W36 first-cycle laying hens to determine the effects of energy concentrations and xylanase supplementation (Hostazym X 100) on hen performance, ME, and body composition. Three concentrations of dietary energy were fed with and without xylanase supplementation in a 3 x 2 factorial arrangement of treatments. Diets were reformulated twice over the experiment (wk 30 and 40) due to increased feed intake or changes in egg production. Dietary energy main effect treatments included a control (C), C - 77 kcal/kg, and C - 154 kcal/kg diets. Egg production, feed intake, BW, egg weight, egg mass, and FE data were collected during the experiment. Nitrogen-corrected AME was determined at 32 and 44 wk of age, and featherless body composition (crude fat, CP, and ash) was determined at 44 wk of age. Hen-day egg production was increased in hens fed dietary xylanase during wk 31 to 40 and 20 to 44. Feed intake was increased with reduced dietary energy during all periods evaluated. Egg mass and FE were improved with xylanase supplementation during wk 31 to 40 and 20 to 44. Hen BW was not different among treatments and egg weight was only significantly different at select time periods with no consistent responses over time. Main effects at hen wk 32 showed that reduced energy resulted in reduced AME(n) and xylanase increased AME(n). In contrast, xylanase treatment resulted in reduced AME(n) when measured at the end of wk 44. overall, supplementation of xylanse to laying hens increased egg production, egg mass, and FE, although AME(n) results were inconsistent and body composition data were dependent on dietary energy.