Effects of Monesin Sodium and Xylanase on Broiler Growth Performance

While antibiotics, such as monensin sodium, have been used safely in poultry feed for decades to improve feed efficiency, there is a growing consumer push to limit their use. In recent years, exogenous xylanase inclusion in diets has increased to improve nutrient digestibility and broiler growth performance. Enzymes have a different mode of action than antibiotics, but their shared outcome of increasing feed efficiency may allow enzymes to replace antibiotics in some poultry diets. The objective of this experiment was to evaluate if a specific commercially-available xylanase can replace monensin sodium, and if the impact differs if birds are fed a higher or lower fiber diet. A total of 216 Cobb 1-d-old chicks (6 birds/cage and 6 cages/treatment) were fed 1 of 6 dietary treatments consisting of a corn- or wheat-based diet supplemented with either 0.01 g/kg monensin sodium (Coban 90; Elanco Animal Health, Greenfield, IN) or 16,000 betaxylanase units/kg beta 1-4, endo-xylanase enzyme (Econase XT; ABVista, Marlborough, UK). Specifically, treatments were: 1) corn-based control; 2) wheat-based control; 3) corn-based with monensin sodium; 4) wheat-based with monensin sodium; 5) corn-based with xylanase; 6) wheat-based with xylanase. Birds were fed in battery cages for 21 days. Body weight gain, total feed intake, and feed conversion ratio (FCR) were calculated and analyzed using the GLIMMIX procedure of SAS. Treatment impacted (P<0.01) final BW, feed intake, and FCR. The corn-based control diet had improved (P <0.05) FCR compared to the wheat-based control diet. In corn-based diets, neither the monensin sodium nor the xylanase improved (P >0.05) FCR compared to the corn-based control. In wheat-based diets, xylanase (P >0.05), but not monensin sodium (P >0.05) improved FCR compared to the wheat-based control. In conclusion, no impact of antibiotics was observed in this experiment, but xylanase improved growth performance in wheat-based diets to equal that of the corn-based control.