|Olk, Daniel - Dan|
Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/1/2007
Publication Date: 3/26/2008
Citation: Mao, J.D., Zhang, T., Lan, Y., Olk, D.C., Ding, G., Ceballos, M. 2008. Chemical Structures of Feces from Conventional and Phytase Transgenic Pigs Investigated by Advanced Solid-State NMR Spectroscopy. Journal of Agricultural and Food Chemistry. 56(6):2131-2138. Interpretive Summary: Excess phosphorus (P) from animal manures is becoming a serious global problem. One way to help solve this problem is to increase the efficiency with which P is used by the animals. This can be done in many ways which include using genetic engineering to modify the animals. Our study used sophisticated chemical characterization techniques (nuclear magnetic resonance spectroscopy (NMR)) to quantify differences in swine manure at two growth stages as a result of genetic engineering the animals and changing their diets (conventional versus low-P). Manure from the modified pigs had higher concentrations of carbohydrates, indicating an effect on either the pig's use of the feed (metabolism) or the microorganisms that live in the animal's digestive tract. This research provides an initial step toward evaluating potential risks and benefits associated with transgenic pigs and will encourage scientists to conduct additional studies using techniques such as NMR.
Technical Abstract: Non-point phosphorus (P) pollution arising from the application of animal manure is becoming a serious global problem. Reducing the amount of P excreted in the manure by changing diet or animal metabolism through genetic engineering may help mitigate this problem. Currently, there are many unanswered questions associated with transgenic pigs and the potential changes in their feces. This study examined the detailed chemical structure of swine feces as affected by genetics, diet, and growth stage. New, advanced solid-state nuclear magnetic resonance (NMR) techniques were used to characterize the feces. Different spectral editing techniques were used to identify specific functional groups. Quantitative NMR techniques were used to quantify the different functional groups and 2-dimentional **1H-**13C heteronuclear correlation NMR was used to detect their connectivities. Feces from conventional and transgenic pigs had similar residual peptide, carbohydrate, and fatty acid components, while those from transgenic pigs did contain more carbohydrates and fewer nonpolar aliphatics. There was no consistent effect of diet (conventional versus low-P) or growth stage (growing versus finishing stage) on chemical structure of the feces. This research provides an initial step toward evaluating potential environmental and health risks associated with transgenic pigs.