| dc.description.abstract | 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. | en |
