Doctor of Philosophy (PhD)
Animal Science (Animal, Dairy, and Poultry Sciences)
This research was conducted to determine the non-phosphorus effects of phytase in diets for swine and poultry. An experiment was conducted to determine the effect of phytase addition on energy availability and protein and fat deposition in growing pigs. Results from this experiment indicated that phytase had small positive effects on energy availability, protein deposition, and fat deposition. In this study, 23 of 29 response variables were at least numerically increased with phytase addition. Two experiments were conducted to determine the accuracy of the energy and amino acid matrix values for Natuphos 1200 in broilers from 0 to 21 or 0 to 42 d posthatching. Results from these experiments indicated that the nutrient matrix values for phytase are accurate, and that they can be used in diet formulations for broilers. Experiments also were conducted to determine the effect of phytase addition to diets with or without the trace mineral premix in nursery, growing, and finishing pigs and in commercial broilers. Results indicated that phytase can replace the trace mineral premix in swine diets. Phytase addition had no negative effect on growth performance or pork quality, and it had minimal effects on carcass traits. In broilers, removing the trace mineral premix had no effect on growth performance but decreased bone breaking strength, and adding phytase did not reverse this response. This research indicates that phytase addition has little effect on carcass traits or meat quality in swine and poultry. When formulating swine diets with phytase, the trace mineral premix can be removed with no negative effects on growth performance or pork quality. However, more research is needed to determine the effect of phytase addition in diets without the trace mineral premix in broilers, because the addition of phytase did not overcome the decrease in bone breaking strength.
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Release the entire work immediately for access worldwide.
Shelton, Jason Layne, "The non-phosphorus effects of dietary phytase in swine and poultry" (2004). LSU Doctoral Dissertations. 2182.