| The purpose of this research was to evaluate the efficacy of a new (novel) xylanase as a feed enzyme for broiler chickens. As the usage of dietary feed enzymes has continued to gain popularity in the poultry industry, numerous new enzymes are identified as potential products. However, each new enzyme must be evaluated for its efficacy in the bird itself. The goal of this research was to evaluate a new mono-component xylanase and its efficacy through feed manufacturing, supplementation to the bird, and quantify the birds' response. In total, seven trials were conducted, two pilot trials and five subsequent trials.;Two trials were conducted using a commercial carbohydrase product and served as a pilot study. These two trials were conducted with the purpose of evaluating a known product and aid in designing the optimal way to evaluate the new xylanase. From the results in these trials it was determined that in addition to growth performance, digesta viscosity and nitrogen-corrected apparent metabolizable energy (AMEn) would be suitable parameters to evaluate the new xylanase.;Initial evaluation of the xylanase was conducted in the starter period (0 to 3 weeks of age), raising birds in battery cages, and supplementing the xylanase to wheat-based diets. A trial was first conducted to evaluate optimal inclusion level of the xylanase in mash diets for broiler chickens in the starter period. The response to the xylanase was evident through a measurable reduction in digesta viscosity, however no growth performance response was observed. A xylanase inclusion level was selected based on bird response data to increasing xylanase inclusion levels. With the selected inclusion level, bird response was evaluated when xylanase was supplemented in reduced energy diets that had been pelleted. Both improvements in live performance and uplifts in AMEn were observed with xylanase supplementation. Feed conversion ratio (FCR) was improved most at the lowest level of dietary energy when xylanase was supplemented. With the low dietary energy level (2,770 kcal/kg), xylanase was included in increasing concentrations in both mash and pelleted (presented to birds as a crumble) diets in a side-by-side comparison. Improvements in FCR and body weight gain (BWG) were observed with xylanase supplementation, however these responses were only observed in the pelleted (crumbled) diets, not in the mash diets.;The following two trials were conducted in litter floor pens and birds were raised to market age. Xylanase was supplemented in reduced-energy wheat-based diets in combination with a dietary phytase, an enzyme commonly included in broiler diets. Inclusion of both enzymes individually resulted in improvements in bird performance and AMEn throughout the production period in reduced energy diets. However, further improvements were observed when enzymes were supplemented to diets not reduced in energy. When the xylanase and phytase were included in combination, great uplifts in AMEn were observed than when either enzyme was included individually. Finally, xylanase was supplemented to reduced-energy corn-soybean meal diets. Xylanase supplementation improved BWG and FCR in the first 14 days, but was not observed by market age. As in the previous trial, improvements due to xylanase supplementation were greater in diets not reduced in energy. While not evident in growth performance, improvements due to xylanase were observed in AMEn evaluated at market age (42 days).;In conclusion, this novel xylanase has potential as a dietary enzyme supplement for broiler chickens. This enzyme presented the heat-stability to withstand the pelleting process (85°C) as well as measurable responses in live performance, reduction in digesta viscosity, and improvements in AME n. |
