Antimicrobials are widely used in North America’s livestock industry. Field application of livestock manure disperses antimicrobials in to the environment. Antimicrobials can increase the level of antimicrobial resistance development in human and livestock pathogens. Three main studies were conducted to: i) quantify the simulated rain runoff losses of chlortetracycline, sulfamethazine and tylosin following surface application vs. soil incorporation of beef cattle feedlot manure; ii) quantify the dissipation kinetics of these antimicrobials in a seasonally-frozen soil following field application of manure; and iii) quantify and compare the dissipation of excreted vs. fortified (that is, added to antimicrobial-free manure) antimicrobials during indoor composting. Manure was sourced from cattle (Bos taurus) receiving no antimicrobial (control), 44 mg chlortetracycline, 44 mg each of chlortetracycline and sulfamethazine, or 11 mg tylosin per kg-1 feed. Antimicrobial concentration in simulated rain runoff following field application of manure generally reflected the corresponding concentrations in manure. Mass loss ranged from 1.7 to 6.5% for chlortetracycline and was 4.8% for sulfamethazine and 0.24% for tylosin. Incorporation of manure into the top 10 cm of soil significantly reduced the mass loss of chlortetracycline and the concentration in runoff of both chlortetracycline and sulfamethazine. Both chlortetracycline and sulfamethazine were persistent in the seasonally-frozen Canadian prairie soil tested. The first-order dissipation half-life (DT50) for chlortetracycline added along with sulfamethazine was 77 d during the growing season and 648 d during the non-growing season. The DT50 of chlortetracycline added alone did not differ significantly between the two seasons (mean DT50 = 121 d). Sulfamethazine was detected throughout the 10-mo monitoring period (mean ≤ 16 ± 10 µg kg-1). Composting dissipated 85–99% of initial concentrations of chlortetracycline, sulfamethazine, and tylosin in manure within 30 d, indicating the potential of composting to minimize the dispersal of these antimicrobials in agroecosystems. The first-order dissipation constant (k) was significantly greater for excreted chlortetracycline (0.29 d-1 - 0.54 d-1) than for the fortified (0.11 d-1 - 0.13 d-1) compound. In contrast, dissipation was significantly greater for fortified sulfamethazine (0.47 d-1) and tylosin (0.31 d-1) than for the excreted antimicrobials (0.08 d-1 for sulfamethazine and 0.07 d-1 for tylosin). / October 2016

Nutrient over-loading in many dairy manure-amended soils in the dairy producing areas of Texas has led to environmental problems as such eutrophication of local surface water bodies. One of the nutrients contributing to eutrophication problems is phosphorus (P). This project focused on fractionation and solubility of selected P forms in an effort to determine a relationship with P found in runoff from dairy manureamend soils. Ten soils (5 calcareous, 5 noncalcareous) were collected from the dairy producing areas of Texas. Triplicate soil samples were analyzed for 0-5 cm and 5-15 cm depths. An acid-base extraction method was used to determine total P (TP), inorganic P, and organic P. Sequential extractions were used to determine the loosely-bound P, iron (Fe) phosphates, aluminum (Al) phosphates, reductant soluble P, occluded apatite P, and calcium (Ca) phosphates for calcareous and noncalcareous samples. The ammonium oxalate method was used to determine extractable Fe, Al, and silicon (Si). Potassium chloride extraction was used to determine soluble Ca, Al, Fe, Mg, and P. A weak NaOH extract was used to determined the amount of bioavalible P. Dissolved P in runoff events and soil pH were collected in a previous study. Calcareous and noncalcareous soils displayed varying concentrations of P indifferent fractions and with separate comparisons, stronger relationships could be achieved. It was also determined that KCl soluble Mg could be used as a predictor for dissolved and total P in runoff for calcareous soils (r2’s ranging from 0.865 to 0.928 and 0.801 to 0.886, respectively). Ammonium oxalate extractable Al also yielded high correlations in calcareous soils for dissolved and total P in runoff (r2 ranging from 0.798 to 0.991 and 0.766 to 0.973, respectively). In noncalareous soils, pH resulted in a less correlated relationship with dissolved P (r2 = 0.600). This study shows that there are simple and effective ways of predicting dissolved and total P in runoff to improve best management practice recommendations for manure-amended soils.

Thesis (Ph. D.)--Ohio State University, 1969. / Includes bibliographical references (leaves 139-143). Available online via OhioLINK's ETD Center

No description available.

No description available.

Two dairy farms on Vancouver Island, B.C., were studied to evaluate nitrogen behavior under different handling and storage conditions. The first farm (U.B.C.) spreads slurry collected daily on a year round basis, while the second (B.M.) stores its slurry in a concrete pit to land dispose under favourable conditions. Feed analysis, slurry sampling, pit profiles and soil profiles were included in the study. Results showed that the nitrogen content of the manure can be reasonably estimated from either feed nitrogen or milk production. Losses of nitrogen during collection and storage in these systems were minimal. / Land and Food Systems, Faculty of / Graduate

No description available.

No description available.

No description available.

Methane is the most abundant organic chemical in the earth's atmosphere. Its abundance in the atmosphere is increasing with time and has reached levels not seen in recent geological history. The methane is produced both naturally, and anthropogenically. One of the sources of anthropogenic methane is manure from domesticated animals. Casada and Safley (1990) estimated the amount of methane generated from this source. This was done by estimating the Methane Conversion Factor (MCF) typically achieved by various waste management systems. This study was done to evaluate those estimates of the MCF. The MCF's for the most dominant of disposal methods, rangeland/pasture disposal, were much lower than the earlier estimates. Other waste management systems, such as solid storage and liquid slurry storage had much higher MCF's, at 20° and 30° C. However, these waste management methods are more prevalent in parts of the world where the average annual temperature is closer to 10° C. At that temperature, the MCF is negligible in all waste management systems. This study showed that the previously reported estimates of MCF for some waste management systems were higher than what was actually the case. Consequently earlier estimates of the amount of methane generated from manures were higher than what this study found. / Graduation date: 1994