The effects of drought-affected grain and carbohydrase inclusion in starter diets on broiler chick performance

Two 18-d studies were conducted to evaluate the effects of drought stress and carbohydrase enzyme inclusion on broiler performance and nutrient digestibility in either yellow dent corn or sorghum. Both experiments employed a 2 × 2 factorial arrangement of treatments with 2 growing environments (normal or stressed), and carbohydrase enzyme cocktail (yes or no). In each experiment, 256 chicks were randomly assigned with 8 birds/pen and 8 replicates/treatment. Enzyme inclusion did not affect any variable in either experiment, and environment did not alter 18-d BW, mortality, or the digestibility of DM or CP. In Experiment 1, birds consuming normal corn had improved FCR compared to those fed drought-affected corn (1.27 vs. 1.33, respectively), which was potentially driven by the difference in apparent total tract digestibility (ATTD) of EE. Alternatively, FCR was not affected by environment in birds fed sorghumbased diets in Experiment 2, but those that consumed normal sorghum had lower feed intake than those fed drought-affected corn (750 vs. 796 g, respectively). In summary, commercial carbohydrase inclusion did not improve growth performance or nutrient digestibility in birds fed normal or drought-affected corn or sorghum. Birds fed drought-affected corn and sorghum affected growth performance variables, but environment did not affect final weight or mortality of broiler chicks.