Enhancement of Growth Performance and Bone Mineralization in Market Broilers through Dietary Enzymes
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Four research experiments were conducted to evaluate the influence of dietary enzyme inclusion (phytase and NSPase) on broiler performance parameters, processing yields, and bone mineralization. In Experiment 1, a 35-day grow out trial was conducted to investigate the effect of three commercially available phytase enzymes on growth performance and bone mineralization in phosphorus deficient corn/soy based diets. Increasing the level of available phosphorus (aP) in the control diets resulted in improved bird performance and bone ash data. The presence of dietary phytase in phosphorus deficient diets resulted in improvements in growth parameters and bone mineralization. Regression analysis confirmed that phytase supplementation can potentially increase the bioavailability of phosphorus in broiler diets up to 0.15 to 0.20 percent, however, the responses varied according to the enzyme used and inclusion level. In Experiment 2, a 42-day grow out trial was conducted to analyze the effects of NSPase inclusion on broiler performance and processing parameters when supplemented in diets with varying protein and energy concentrations. Reduced protein and energy levels reduced bird performance throughout the trial. The inclusion of both NSPase enzymes resulted in improvements in feed conversion throughout the starter and grower periods (day 26 of age). The results from this trial showed that NSPase inclusion can improve broiler performance and processing parameters. In Experiments 3 and 4, a battery trial and a floor trial were conducted to determine the effects of phytase and NSPase enzyme co-administration on growth and bone ash in low phosphorus diets. Increasing the level of available phosphorus resulted in increased bird performance and bone ash. The inclusion of phytase enhanced bird performance and bone mineralization. NSPase inclusion in diets containing low levels of phytase had improvements in bird performance during early stages of growth. The enhanced effects associated with dual administration of phytase and NSPase were not observed in a full grow out trial during later stages of growth. These four experiments indicate that phytase and NSPase enzyme inclusion in broiler diets have the ability to enhance bird performance, processing yield, and bone mineralization.
Coppedge, Jacob Ryan (2010). Enhancement of Growth Performance and Bone Mineralization in Market Broilers through Dietary Enzymes. Master's thesis, Texas A&M University. Available electronically from