2012 Annual Report
Fate and disposition studies were conducted with labeled chlorine dioxide gas on edible fruits, vegetables, and/or melons. Regardless of the crop group tested, the most prevalent chlorine dioxide metabolite was chloride ion (a natural product). In some cases, residues related to chlorine dioxide treatment were completely absent from edible tissues. Such results suggest that chlorine dioxide gas could be a viable method for removing pathogens from produce intended for human consumption.
A penicillin G procaine residue depletion study was initiated in heavy sows. Heavy sows were treated in an off-label manner to replicate industry practices and sows were killed with withdrawal periods ranging from 5 to 39 days. Tissues were collected from each animal for qualitative and quantitative analyses. The live phase of the study has been completed and analysis of tissues is underway.
The fate of estradiol was monitored for 42 d in laboratory-scale anaerobic digesters. Estradiol decreased rapidly in the liquid layer of the digester and reached steady state concentrations by 4 days at about 20% of the initial dose. Estrogen was rapidly transformed to estrone, which adsorbed quickly to sludge; about 25% of the estradiol was metabolized to methane. A large decline in estrogen will occur during anaerobic digestion and coupling the anaerobic process to aerobic treatment may serve to completely destroy all estrogen.
Chlortetracycline is an antibiotic frequently utilized in swine production. Because chlortetracycline is excreted unchanged in the feces, relatively high amounts are found in hog wastes. A sensitive and specific analytical method was developed to measure chlortetracycline and its degradation products in hog wastes. The method was used to determine chlortetracycline and its degradation products as a function of time in swine manure incubated at three different temperatures. Higher temperatures accelerated the decomposition of chlortetracycline and the formation of isochlortetracycline, a product with little or no antibiotic activity. Environmental loads of chlortetracycline may be overestimated if the method of analysis does not distinguish between chlortetracycline and isochlortetracycline.
Shappell, N.W., Mostrom, M.S., Lenneman, E.M. 2012. E-Screen evaluation of sugar beet feedstuffs in a case of reduced embryo transfer efficiencies in cattle: the role of phytoestrogens and zearalenone. In Vitro Cellular and Developmental Biology - Animals. 48:216-228.
Guy, A.C., DeSutter, T.M., Casey, F.X.M., Kolka, R., Hakk, H. 2012. Water quality, sediment, and soil characteristics near Fargo-Moorhead urban areas as affected by major flooding of the Red River of the North. Journal of Environmental Quality. 41:554-563.
Shelver, W.L., Varel, V.H. 2012. Development of a UHPLC-MS/MS method for the measurement of chlortetracycline degradation in swine manure. Analytical and Bioanalytical Chemistry. 402:1931-1939.
Smith, D.J., Barri, A., Herges, G.R., Hahn, J., Yersin, A.G., Jourdan, A. 2012. In vitro dissolution and in vivo absorption of calcium [1-14C]butyrate in free or protected forms. Journal of Agricultural and Food Chemistry. 60:3151-3157.
Medina, M.B., Shelver, W.L., Fratamico, P.M., Fortis, L., Narang, N., Cray, Jr., W., Esteban, E., Tillman, G., Debroy, C. 2012. Latex agglutination assays for detection and of non-O157 Shiga toxin-producing E. coli serogroups O26, O45, O103, O111, O121 and O145. Journal of Food Protection. 75(5):819-826.
Dammann, A.A., Shappell, N.W., Bartell, S.E., Schoenfuss, H.L. 2011. Comparing biological effects and potencies of estrone and 17 B-estradiol in mature fathead minnows, Pimephales promelas. Aquatic Toxicology. 105:559-568.