Using ruminally, abomasally and ileally cannulated wethers, an in vivo experiment was conducted to compare supplementing ensiled, deepstacked and composted broiler litter as N sources with soybean meal. Sheep were fed isonitrogenous (10.3% CP) and isocaloric (56% TDN) corn cob-based diets. Apparent digestibility of CP was somewhat depressed by feeding deepstacked and composted litters; however, N retention was affected by N sources. Nitrogen source did not alter flow and partial digestion of DM, OM and ADF through the digestive tract of sheep, with the exception of higher OM digestion in the large intestine of sheep fed deepstacked and composted litters than ensiled litter. Diets containing soybean meal, and ensiled, deepstacked and composted litter had 12.2, 25.2, 29.1, and 25.5% protein undegradability, respectively. Feeding litter increased dietary undegraded N flow and decreased microbial N flOw, compared to feeding soybean meal. Efficiency of microbial protein synthesis was not affected by N source. Available N (g/d) in the small intestine was similar among all diets. An in situ bag experiment showed that CP of ensiled, deepstacked and composted litter consisted of 80 to 89% of soluble A fraction, 8 to 13% of degradable B fraction, and 3 to 6% of undegradable C fraction. The ruminal degradability of CP was approximately 89 to 94% for processed litters, and 75% for soybean meal. Nitrogen solubilities of ensiled, deepstacked and composted broiler litter, determined in autoclaved ruminal fluid, were 62, 59, and 41%, respectively, when that of soybean meal was 12%. Another in situ experiment was conducted to determine ruminal DM and CP characteristics of broiler litter from surface and charred areas in the deepstacks. The low DM content in charred litter reflected more susceptibility of the locally high moisture litter for charring. Surface litter contained less CP than normal litter. Charred litter had higher undegradable protein fractions and lower CP degradability than normal litter. These studies illustrated that broiler litter processed by ensiling, deepstacking and composting could be efficiently utilized as a protein source for ruminants. / Ph. D.

M. S.

A small silo study was conducted to determine the optimum combination of slurry and fresh dairy waste and crop residues to achieve good ensiling. Slurry waste that had been accumulated in slurry storage tanks and dairy waste scraped from the barn were ensiled with ground corn stover, with and without the addition of 5% molasses, to achieve two dry matter levels of 30 and 35%. Fermentation, as measured by pH, lactic acid and disappearance of soluble carbohydrates, occurred in all silage mixtures. Lactic acid levels indicated that a more desirable fermentation had occurred in the waste silages containing molasses. Total and fecal coliforms and salmonella, shigella and proteus organisms were either destroyed or essentially eliminated following ensiling. A large silo study was conducted with the mixtures containing molasses. The fresh waste was diluted with water to achieve the same dry matter levels as the slurry waste. The mixtures for the 30 and 40% dry matter levels were 71:39 and 64:36 cattle waste to wheat straw, wet basis. Active fermentation occurred in all silages and pH was lower and lactic acid levels were much higher than they were in the small silo. In a metabolism trial conducted with lambs, the following diets were fed: 1) 50% orchardgrass hay, 38.3% ground corn, 11.4% soybean meal and .3% limestone (basal diet); 2) 50% basal and 50% ground wheat straw ensiled at 50% dry matter (negative control); 3) 50% basal and 50% 71:29 slurry-wheat straw silage; 4) 50% basal and 50% 64:36 slurry-wheat straw silage; 5) 50% basal and 50% 71:29 fresh waste-wheat straw silage and 50% basal and 50% 64:36 fresh waste-wheat straw silage (proportions of basal and silages were on a dry basis). Apparent dry matter digestibility was higher (P < .01) for the basal diet than for the silage diets and was higher for the waste containing silages (P < .05) than for the wheat straw silage diet. Dry matter digestibility of the waste-containing silages, calculated by difference, was not different, but was higher (P < .01) than for the ensiled wheat straw alone. Nitrogen digestibility was higher (P < .05) for the waste containing silages, compared to the wheat straw silage but lower (P < .05) than the basal ration. All lambs were in positive nitrogen balance, with the lambs fed the 71:39 slurry waste silage slightly higher than for those fed the other diets. The lambs fed the basal and wheat straw silages had similar nitrogen retention. Ruminal ammonia levels were highest (P < .05) for the lambs fed the basal and lowest for those fed the wheat straw silage diet. There were no significant differences (P < .05) among the waste-containing silages. The palatability trial with lambs was conducted using 50% basal and 50% of the silages, dry basis. Dry matter intake was highest (P < .05) for the basal diet. Dry matter intake among the silage diets was lowest (P < .05) for the slurry waste silage diets. Among the waste-containing silage diets, dry matter intake tended to be higher for the fresh waste silages, compared to the slurry waste silages of similar dry matter. / M.S.

Three experiments were conducted with fresh caged layer waste collected within 24 h after excretion. The waste was stored uncovered for 42 d in polyethylene lined 210 liter metal drums. In the first experiment, waste was treated with no additive, 1 and 1.5% formaldehyde, 1.5 and 2% sodium metabisulfite and 1. 5 and 2% propionic/formic acid (1: 1, w/w). In the second experiment, the additives used were: none, 1% formaldehyde, 1.5% sodium metabisulfite, 1.5% propionic/formic (1: 1, w/w), 10% dry sugar cane molasses and 10% dry molasses plus 2% sodium chloride (salt). In this experiment, the wastes were ensiled with wheat straw (60:40, wet basis) in 4-liter cardboard containers double lined with polyethylene with the following additives: control, 10% dry molasses, silage inoculant or 10% dry molasses plus inoculant. In the third study, the preservatives were: untreated, 1% formaldehyde, 10% dry molasses or 10% dry molasses and 2% salt. After 42 d, treated wastes and straw (60:40) were ensiled with 10% dry molasses in 210 liter metal drums doubled lined with polyethylene. A metabolism trial was conducted with 30 crossbred wethers fed a basal diet alone or with silages containing the wastes which had been treated with the preservatives (1:1, dry basis). In all studies, putrefaction, maggot infestation and dark color were observed for untreated waste. The tops of the wastes treated with sodium metabisulfite and formaldehyde were covered with mold. Formaldehyde-treated waste maintained a stable pH, and water-soluble carbohydrate level. The higher level of propionic/formic acid was effective against visible deterioration. The pH of the silages containing molasses-treated waste was lower than for silages containing control or chemically-treated wastes. Adding molasses at ensiling reduced pH and increased lactic acid. Digestibilities of organic matter, crude protein and neutral detergent fiber were lower (P<.05) for the diet containing silage made from untreated waste, compared to diets containing silage made from treated waste. In all studies, putrefaction, maggot infestation and dark color were observed for untreated waste. The tops of the wastes treated with sodium metabisulfite and formaldehyde were covered with mold. Formaldehyde treated waste maintained a stable pH, and water-soluble carbohydrate level. The higher level of propionic/formic acid was effective against visible deterioration. The pH of the the silages containing molasses-treated waste was lower than for silages containing control or chemically-treated wastes. Adding molasses at ensiling reduced pH and increased lactic acid. Digestibilities of organic matter, crude protein and neutral detergent fiber were lower (P<.05) for the diet containing silage made from untreated waste, compared to diets containing silage made from treated waste. / Master of Science

Master of Science

published_or_final_version / Botany / Master / Master of Philosophy

No description available.

Thesis (Master of Engineering in Chemical Engineering)--Cape Peninsula University of Technology, 2017. / For more than a decade, poultry product consumption increased in developed and developing countries, with more than 470 new slaughterhouses being constructed in South Africa (SA). Customer demand for poultry products resulted in a rapidly growing poultry industry, with consequential increases in the quantity of organic solid and liquid waste being produced from the poultry slaughterhouses. Annually, the productivity and profitability within the livestock production sector has increased, an evaluation based on the number of slaughtered and sold animals. Potable water is required for these animals, resulting in the generation of high strength wastewaters. Instantaneous disposal of such wastewaters into the environment is concerning as it results in odour and the spreading of diseases in local rivers and freshwater sources. The generated poultry slaughterhouse wastewater (PSW) contains a high quantity of biodegradable organic, suspended and colloidal matter in the form of proteins, fats, oil and grease (FOG), protein from meat, blood, skin, and feathers, resulting in high Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD), which can contribute to environmental deterioration if not treated adequately before discharge. On average, PSW contains a high concentration of BOD, COD, nitrogen, pathogenic and non-pathogenic viruses, bacteria and parasites, including their eggs. These characteristics make PSW highly polluted with a large quantity of bird carcass debris including FOG. Due to the high concentration of organic matter and suspended solids in the wastewater, it is necessary to pre-treat the PSW prior to sequential anaerobic treatment. Most of the contaminants present in the PSW can be reduced by means of numerous treatment steps, i.e. physical, chemical and biological treatment. For this study, biological treatment methods, physical separation methods, and a membrane bioreactor system, were used to treat PSW. The biological treatment methods used were an anaerobic digester (AD) followed by a single stage nitrification/denitrification reactor and then a third stage in which an ultrafiltration (UF) and Microfiltration (MF) membrane bioreactor (MBR) was used. The AD used was an Expanded Granular sludge Bed Reactor (EGSB) as anaerobic digestion is one of the most effective biological wastewater treatment methods used, as it reduces the organic matter to even produce biogas as a renewable energy source. The basis of anaerobic treatment method relies on suitable bacteria cultivated in the absence of dissolved oxygen, facilitating decomposition of organic matter into a renewable source such as biogas. Similarly, biological nitrification/denitrification processes for the removal of total nitrogen (TN) in wastewater has become one of the most commonly used processes within the wastewater treatment sector. Nitrification and denitrification processes can be performed by some microorganisms within the wastewater in Wastewater Treatment Plants (WWTPs) The PSW used was collected at different times from a local poultry slaughterhouse in the Western Cape (South Africa) and stored in a refrigerator at 4°C until it was fed to the first stage of the treatment which was the EGSB. Before being fed to the EGSB, the PSW was filtered with a sieve to remove feathers and agglomerated FOG to avoid clogging of the tubing. The EGSB was inoculated with 0.747 L anaerobic granular sludge, had a working volume of 2.7 L, an inner diameter of 0.065 m and a height of 0.872 m respectively. Ceramic marbles with an average diameter of 0.0157m were placed at the bottom of the bioreactor as packing for the underdrain and to maintain the granular sludge within the heated section of the bioreactor. The EGSB was fed with three types of PSW: 50% (v/v), 70% (v/v), which was diluted with distilled water. Thereafter once the system stabilised the reactor was fed with undiluted PSW (100%). Each dilution was operated at different Hydraulic Retention Times (HRTs) and Organic Loading Rates (OLRs), with average HRTs used being 62.5, 57.5 and 49.65 h. Furthermore, the average OLRs were 1, 2 and 3 g tCOD/L.day respectively. The performance of the EGSB was determined using tCOD, Total Suspended Solids (TSS) and FOG, with overall averaged removal rates for these constituents being 69%, 98% and 92% respectively. The highest tCOD removal of 93 % (optimal efficiency) was obtained at an average HRT of 57.5 h with a corresponding average OLR of 2 g tCOD/L.day.

Agriculture is key to New Zealand�s economy with land-use conversions in response to market forces occurring regularly. Recently, high-intensity dairy farming has replaced low-density livestock farming, often degrading surrounding waterways. Of particular concern is that dairy cattle can be a source of the parasite Giardia, which in humans is a common cause of gastrointestinal infection. Thus, this thesis evaluated whether dairy farm conversions posed significant consequences for public health. First I examined the prevalence of Giardia in calves in a rapidly intensifying dairying region of New Zealand. A total of 1190 faecal samples were collected from calves one to seven weeks old during two spring calving seasons and screened by direct immunofluorescent microscopy. Giardia cysts were detected in 31% of samples. To evaluate the potential risk that this environmental source of Giardia posed to the human population, molecular genotyping was used to compare forty Giardia strains isolated from calves with thirty isolates from humans collected in the same region and period. Sequencing the β-giardin gene, Giardia duodenalis assemblages A and B were identified from both hosts, with genotype comparisons revealing substantial overlap of identical genotypes for both assemblages, implying zoonotic transmission. Environmental agencies routinely promote the planting of streamside edges to decrease nonpoint pollution from dairy farms entering waterways. However, current methods for tracking pathogens across farmland and into waterways via surface runoff are limited and typically have been developed using artificially created landscapes. Furthermore, no studies have investigated how Giardia moves across the landscape in farm surface runoff. I developed a field-based tracking method specific for Giardia and used this technique to compare the ability of recently planted vegetation strips with bare soil strips cleared of vegetation at decreasing pathogen concentrations; a typical scenario when planting barriers to reduce waterway contamination. A spike containing a bromide tracer and inactivated Giardia cysts was applied in drip-irrigated surface runoff, with one-minute samples collected from the bottom of the plot. A significant treatment effect was identified for Giardia, with 26% fewer detected in runoff from the planted strip, highlighting the immediate benefit of vegetation planting in removing pathogens. Next I evaluated the effects of four riparian treatments on Giardia runoff: exotic pasture grass and weeds growing in the absence of cattle grazing due to fencing, in comparison to monocultural plantings of three New Zealand native grassland species. Runoff experiments were performed after planting, both prior to and following the main summer growing season. Bromide recovery was high from all four treatments (54 - 99%), with no significant treatment effects. By comparison, Giardia recovery was low (1 - 13%). Prior to summer, two native species reduced Giardia in runoff more than the pasture grass/weed treatment which was almost vegetation-free at this time. After summer, Giardia recoveries were uniformly lower in all treatments. These results demonstrate that after one growing season, fencing waterways produces riparian buffers, via the growth of exotic pasture plants released from grazing, that decrease pathogen concentrations in surface runoff to concentrations indistinguishable from native plantings. Given infectious organisms are known to be in the environment, it is important to assess the risk these pose to human populations. Findings from this research can be used to improve currently available risk-assessment models for Giardia transmission from infected dairy animals via water to humans.

[Abstract]: The disposal of animal waste has become a problem in many parts of the world due to the rapid growth in the number and the size of intensive animal industries. Safe waste disposal sites are rarely available and the relocation and/or treatment of animal waste is seldom economically viable. The reuse of animal waste for energy recovery and re-feeding is also not popular. Animal waste is a valuable source of plant nutrients and a very good soil conditioner, and has been commonly applied as fertiliser to agricultural fields. However, due to the increasing oversupply of animal waste in recent years, it has often been applied in excess to the agricultural fields. Excessive application of animal waste, without due consideration of its implications, is a serious concern. The run-off and leaching losses of nutrients from the fields fertilised with animal waste have contributed significantly to the eutrophication and toxic blue-green algae blooms in surface water systems and nitrification of ground water systems. It has also led to nutrient imbalances in the soils and odour pollution to the surrounding communities. The animal waste, which is a valuable source of plant nutrients, has thus become both an economic and environmental burden, and there is a need to develop a strategy for its sensible use as a fertiliser in agricultural fields. Sensible use of animal waste involves the consideration of all the agricultural, environmental, social, and economical limitations. A rational method of achieving this is to restrict the use of animal waste to sites suitable for such uses, identify areas where it can be relocated and applied economically, limit the application rates to a safe level, and observe appropriate manure management practices. This study addressed each of these components by developing a comprehensive manure application plan (MAP) for the site-specific use of animal waste as fertiliser in agricultural fields. Various geographic information systems (GIS) based techniques, including a weighted linear combination model and map algebra based cartographic modelling, were employed to achieve the goal. The appropriateness of the existing techniques and procedures were evaluated and modified to meet the current input requirements. New methods of analysis were devised as necessary. The Westbrook sub-catchment of the Condamine River catchment in south-east Queensland was selected as the study area. The sub-catchment covers 24,903 hectares and contains 39 intensive animal industries. The catchment is also a part of the Murray-Darling Basin, which has been suffering from toxic blue green algae blooms recurrently since 1991. This study identified that only about one-fifth of the sub-catchment area is suitable for animal waste application. Depending on the method of site suitability analysis and the number of input factors used the suitable area ranged between 16 and 22 percent. This comparatively small area is mainly due to the presence of a large proportion of non-agricultural areas in the sub-catchment. The suitable areas were also found to have various degrees of suitability for waste application. However, the degree of site suitability was affected by the number of input factors used in the analysis, the weighting of the factors, and the method of factor attribute standardisation. Conventional methods of weighting input factors were found to be cumbersome and not particularly suitable. Hence, this study developed a new ‘objective oriented comparison’ method of factor weighting. Standardisation of input factors using a continuous, rather than discrete, classification (ie fuzzy set) method was found to be more consistent in degree of suitability determination. The discrete classification of factor attributes into classes of different numbers and sizes, and the weighting of classes to a sum of one, were identified as a limitation in using this standardisation method. A new ‘weight adjustment’ method was devised and demonstrated to reduce factor-weighting biases. The suitable sites, degree of site suitability, and other relevant spatial and non-spatial information were processed within a GIS framework to develop a comprehensive manure application plan. The inherently high presence of available phosphorus in the soils of the study area was recognised and the P2O5 content in the manure was used as the basis for determining manure application rates. A complimentary nitrogen supply map was also generated. Manure management practices applicable to the areas with a lower degree of suitability were also suggested.