Date of this Version
Duerschner, J. (2018) Effect of Swine Manure Pit Additives and Facility Disinfectants on the Fate of Antibiotics and Manure Composition During Simulated Swine Manure Slurry Storage.
This thesis investigates the effect of time and of swine manure slurry treatment on the physical properties, nutrient content, and the concentrations of antibiotics chlortetracycline, lincomycin, and tiamulin in simulated storage of swine manure. In one experiment the slurry was treated with six additive products. In a second experiment a set of four disinfectant products were used. Control consisted of unamended slurry. Manure was stored in 60 liter stainless steel bioreactors to simulate deep pit storage and was sampled 7 times over a 40 day incubation.
From an ANOVA of the results, it was concluded that evaporation may be contributing a significant effect in concentration change of the manure constituents. With this in mind, each time series was normalized by its final time point and a second ANOVA was performed along with a growth curve analysis on the means and slopes over time of the normalized data. This further analysis resulted in a large decrease in treatment effects in the additives experiment but demonstrated no reduction in treatment effects in the disinfectants experiment.
With the additives experiment the Coban 90 treatment produced an increase in mean total suspended solids relative to the control. Five of the additive products produced a slower decrease in electrical conductivity relative to the control. Only one additive treatment was found to produce a greater mean tiamulin concentration relative to the control over the course of the experiment.
With the disinfectants experiment, two treatments increased mean concentrations of total nitrogen. Another two treatments caused an increase in mean phosphorus concentration. Once again, only one treatment produced an increase in mean tiamulin concentrations. The antibiotics concentrations reported in both experiments were highly variable and could not be fit accurately to decay models.
Advisors: Shannon Bartelt-Hunt and Amy Schmidt