Magister Scientiae (Biodiversity and Conservation Biology) / Homopus areolatus is an endemic terrestrial tortoise that resides in a Mediterranean type of climate, which is characterised by winter rainfall and mild winter temperatures. Within ectotherms, such as H. areolatus, physiological changes are elicited by changes in the ambient temperature. These physiological changes are evident in the blood profile of reptiles. I described the morphology of immature and mature erythrocytes, leukocytes as well as thrombocytes of H. areolatus. Additionally, I evaluated erythrocytes, leukocytes and thrombocytes to assess the effects of season and cohort on these cells. Blood samples were collected in 2000 and 2001 at Elandsberg Nature Reserve in the Western Cape from H. areolatus cohorts (female, male, juvenile) in all seasons (spring, summer, autumn, winter). Blood smears were made and stained with modified Giemsa stain. SigmaStat was used for all statistical analysis. Immature erythrocyte types within H. areolatus included basophilic rubricytes, polychromatophilic rubricytes and polychromatophilic erythrocytes. Upon my evaluation, I encountered evidence to suggest that small and large immature erythrocytes possibly developed from two distinctive lineages. Further research is required to discern which lineage gave rise to which immature erythrocyte type. Cohort had no effect upon immature erythrocytes. Erythropoiesis was most prevalent during winter and spring within H. areolatus. Aberrant features of erythrocytes appeared to be more prevalent during autumn, which signified the driest season with limited food and water. Mature erythrocytes play a huge role in oxygen transport and metabolism in individuals. Factors such as size and shape are relevant since small, mature, ellipsoidal erythrocytes transport oxygen more efficiently than large, spherical erythrocytes. In H. areolatus small, mature, ellipsoidal erythrocytes appeared to be most prevalent during spring and summer. During winter however, large, spherical erythrocytes appeared to be most prevalent. Thrombocytes and seven types of leukocytes were observed within H. areolatus, namely heterophils, lymphocytes, eosinophils, basophils, monocytes, plasma cells and azurophils. Among cohort and season heterophils were most prevalent overall, followed by lymphocytes and eosinophils respectively. Basophils, monocytes, plasma cells and azurophils were present but overall, were relatively few. H. areolatus appeared to be healthy, and leukocyte counts as well as its dimensions appeared to be in accordance with other reptilian studies. This study serves as the first baseline haematological reference forH. areolatus. The study forms the second of its kind on South African tortoises, only one other haematological study has been done namely, P. geometricus which is a sympatric species to H. areolatus.

Infection data were obtained monthly from June, 1999 to September, 2000 at the University ofKentucky dairy. Quarter foremilk samples were collected for bacteriological determination andsomatic cell counts (SCC). The Livestock Stress Index (LSI) estimated heat stress and is calculatedby combination of temperature and humidity. For uninfected quarters the geometric mean SCC was29,000 cells/ml. For infected quarters the geometric mean SCC was 213,000 cells/ml. Coagulasenegativestaphylococci (CNS) infections comprised 61 percent of the total infected quarters with ageometric mean SCC of 155,000 cells/ml. Staphylococcus aureus infected quarters had a geometricmean SCC of 680,000 cells/ml. There were no significant correlations between log SCC and LSIwhen looking at the total sample period. However, evaluating October, 1999 through September,2000, significant correlations were found for LSI and log SCC of uninfected quarters (P andlt; 0.05) and`infected quarters (P andlt; 0.0001). All correlation coefficients were less than 0.12. The results suggest nomarked changes in SCC were observed in uninfected quarters during hot summer weather. Hotsummer weather may have a minor impact on SCC in infected quarters, but the effect is variable.Thus, infection status of the mammary gland, not heat stress, is the major factor determining SCC.

Magister Scientiae (Biodiversity and Conservation Biology) - MSc (Biodiv and Cons Biol) / The geometric tortoise is one of the world‟s rarest terrestrial tortoises and is endemic to the Southwestern Cape, South Africa. There has been cause for conservation concern for Psammobates geometricus, yet as is common for many species, quantitative physiological research has been lacking. Considering the important role of red blood cells in oxygen circulation, and the role of white blood cells in immune resistance, blood profiles have been used across taxa as a reliable indicator of health status and physiological processes. Forming part of a larger chelonian conservation programme in South Africa, I studied the haematological changes in P. geometricus, to better understand their physiological responses to changes in climatic conditions. Sampled peripheral blood from males, females and juveniles of the largest known wild geometric tortoise population over four seasons (spring, summer, autumn and winter) from August 2000 to June 2001. Blood samples were used to make smears and determine red cell count (RCC), packed cell volume (PCV), haemoglobi concentration (Hb), red cell indices and differential white cell counts. Digital imaging analysis was used for the histological evaluation of stained blood smears, including descriptions of red and white blood cell morphologies, as well as erythrocyte developmental stages. In the cooler periods, geometric tortoises showed low Hb and mean cell haemoglobin concentration values. Erythrocytes were larger and rounder in winter and spring, which were likely due to hydration states. In addition, increased numbers of immature erythrocytes in circulation suggested an erythropoietic response in winter and spring. This regenerative response is common in reptiles emerging from periods of limited activity and is associated with increasing primary production following rainfall events. In the following summer and autumn, increased mean cell haemoglobin concentrations suggested elevated metabolic rates influenced by rising temperatures. This would seem pertinent to meet the extra physical demands associated with foraging effort in the season characterised with limited water and food supply, and mating behaviour, which occurs in the summer. Low body conditions across all cohorts provided evidence for nutrition stress, while erythrocyte size, shape and degenerative responses indicated dehydration stress. Physiological responses to seasonal influences are specific to growth or reproductive demands and differed for each cohort. Males experienced increased Hb, PCV, RCC, and erythrocyte sizes in summer and autumn, which relate to the erythropoieticstimulating effects of androgens. Female erythropoietic cycles in spring accommodate the increased metabolic demands of increased foraging needed for a larger body size and egg production, and again in autumn again for vitellogenesis. Juvenile tortoises showed minimal differences, and could indicate species-specific responses to environmental changes. A spring-related erythropoiesis was observed in juveniles while during summer and autumn, juveniles showed less evidence for dehydration stress than in adults. No haemoparasites were observed in peripheral blood. Seven leukocyte types were identified and included heterophils, eosinophils, basophils, lymphocytes, plasma cells, monocytes and azurophils, in addition to thrombocytes. Heterophils were the most abundant leukocyte, followed by lymphocytes and eosinophils while monocytes and basophils were equally low; plasma cells and azurophils were rare. Heterophil counts were higher in spring than in summer and autumn, and in summer, were more abundant in females than in juveniles. Eosinophil counts were low in spring for all cohorts, and additionally, female and juvenile counts were low in summer. Eosinophils in juveniles were significantly lower than in adults in winter and spring. Lymphocyte numbers increased in autumn for all cohorts, while summer counts were higher in juveniles than in adults. Basophils and monocytes showed minimal seasonal changes, although basophil counts in females in winter tended to be high. Thrombocytes were lowest in spring for all cohorts. Understanding the physiological responses associated with seasonal changes and for each cohort is critical for effective chelonian conservation management. Results obtained from this study indicate a clinically healthy population of Psammobates geometricus and represented the first of this kind to establish baseline haematological reference data for this Critically Endangered tortoise species.

Objective 1 was to investigate effects of heat stress and breed on milk and component yield for Holstein and Jersey cows on the same farm. Objective 2 was to determine the effects of breed on udder health as measured by somatic cell count (SCC) during times of heat stress. Data were collected from DHIA records of 142 Jersey cows and 586 Holstein cows from the University herd at Mississippi State University. During heat stress Jersey milk yield and 4% fat corrected milk (FCM) increased (P<0.01). Holstein milk yield and FCM decreased during heat stress (P<0.01). Heat stress affected somatic cell count (SCC) although effects varied by intensity of heat stress. Breed did not have an affect on SCC. Milk fat and protein percentages declined for both breeds in heat stress conditions. Milk fat but not milk protein of Jersey cows increased as stress increased from mild to severe.

This project investigated the bacteria in water entering and leaving the slow sand filters at Ringsjö Water Works using flow cytometry. The purpose was to explore the possibility of utilising flow cytometry as a monitoring method for optimising water production using slow sand filters. Data describing the bacterial community in water was collected over seven weeks and analysed with FlowJo, flow cytometric image comparison and Minitab. The total cell count, intact cell count and the percentage of high nucleic acid bacteria were analysed. These parameters were highly dependent on scraping events, water entering the filters and season. The results indicated that flow cytometry has great potential for use as a monitoring method, although more data should be collected to establish expected trends and secure baseline values for routine comparisons. / <p>Fördröjning av publikation fram till 31 december 2020.</p>

No description available.

Mastitis is one of the most costly diseases to dairy producers around the world with milk yield loss being the biggest contributor to economic losses. The objective of first study of this thesis was to determine the impacts of high somatic cell counts on milk yield loss. To accomplish this, over one million cow data records were collected from Southeastern US dairy herds. The objective of the second study was to determine optimum treatment cost of clinical mastitis by combining two economic modeling approaches used in animal health economics. The last objective of this thesis was to determine how much Southeastern US dairy producers are spending to control milk quality on farm and determine if they understand how milk quality affects them economically. This was accomplished through a collaborative project within the Southeast Quality Milk Initiative.

A research report submitted to the faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in partial fulfillment of the requirements for the degree of Master of Science in Medicine (Pharmacotherapy) / Background: The decision of when to start treatment in an HIV-infected individual has always been problematic as far as CD4 count is concerned. Aims: To determine the clinical outcome of patients who commence HAART at different CD4 cell count levels. Method: Retrospective analysis of records of a cohort of patients who are received ART at workplace wellness clinics in three mines in Limpopo province from January 2003 to December 2009. Patients were divided into three groups based on their baseline, group A (CD4 <100), group B (CD4 101-200) and group C (CD4 201-250) Each patient’s data was analyzed one year after his/her commencement. Results: The percentage of patients who died in group A (16%) differs significantly from the percentage of patients who died in group B (4%) (Fisher exact test p= 0.038) and also differ significantly from the percentage of patients who died in group C (0%) (Fisher exact test p= 0.011). The percentages of patients who developed TB in the three groups are 8%, 8% and 2.9% respectively. When compared statistically, these percentages do not differ significantly (Fisher exact test p=0.059).The percentages of patients with severe bacterial pneumonia in the three groups (2%, 2% and 0% respectively) do not differ significantly (Fisher exact test p=0,276).The percentage of hospital admissions for patients in group A (18%) differ significantly from the percentage in group B (6%) and the percentage in group C (6%) (Fisher exact test p= 0.05). The percentage of patients with weight loss of more than 10% of baseline value in group A (24%) differ significantly from the percentage in group B (4%) (Fisher exact test p= 0.003) and also differ significantly to from the percentage in group C (0%) (Fisher exact test p= 0.001). The percentage of patients with undetectable viral load in group B (89%) is significantly different from the percentage in group A (69%) (Fisher exact test p= 0.03) and is also significantly different from the percentage in group C (61%) (Fisher exact test p= 0.008).The change in mean CD4 cell count was found to be statistically significant within each group (paired t test, p<0.0001), but the mean changes between the three groups (132,141 and 172) respectively, do not differ significantly (ANOVA test). Conclusion: Patients with baseline CD4 cell count of less than 100 have a poor clinical outcome when compared to patients with baseline CD4 cell count of more than 100. Efforts must be made to identify patients early before CD4 cell count fall to below 100 and preferably initiate HAART when CD4 cell count is above 200.

Os objetivos gerais deste estudo foram avaliar o efeito suplementação de zinco (Zn), cobre (Cu) e selênio (Se) orgânicos para vacas leiteiras e os seus efeitos sobre a qualidade do leite, saúde da glândula mamária e consumo de alimentos. Os objetivos específicos foram avaliar: a contagem de células somáticas (CCS), a prevalência de mastite clínica e subclínica,a produção e composição de leite nos 80 primeiros dias de lactação; monitorar a atividade enzimática de superóxido dismutase (CuZnSOD), glutationa peroxidase (GSH-Px) e ceruloplasmina (CP); o consumo de alimentos; a concentração plasmática de Zn, Cu e Se; e as variações de peso e escore dos animais. Dezenove vacas leiteiras, com prenhez confirmada, foram selecionadas por peso, escore de condição corporal (ECC), número de lactações e produção de leite da lactação anterior, e distribuídas ao acaso em dois grupos para receber fontes de Zn, Cu e Se orgânica (n=9) ou inorgânica (n=10). As dietas foram formuladas para suprir os requerimentos nutricionais dos animais dos 60 dias antes da data prevista do parto aos 80 dias de lactação. Amostras dos alimentos fornecidos e das sobras foram coletadas diariamente para posterior análise de composição. O leite foi coletado semanalmente a partir da 3ª semana de lactação para determinação da composição e CCS, e nos dias 1 e 7 de lactação, e quando diagnosticados casos clínicos de mastite, para cultura microbiológica. Amostras de sangue foram coletadas aos -60, -21, 1, 21, 40 e 80 dias do período experimental para análises da concentração de CuZnSOD, GSH-Px e CP. Para determinação das concentrações plasmáticas de Zn, Cu e Se amostras de sangue foram coletas aos 60 dias antes da data prevista de parto, e no 1º, 40º e 80º dias de lactação. Avaliações do escore de condição corporal (ECC) e do peso corporal (PC) foram realizadas no início e final do experimento, no parto, e uma vez por semana durante todo o período experimental. A incidência (novos casos)e o total de casos de mastite subclínica foi menor para o grupo de vacas alimentadas com fontes orgânicas de Zn, Cu e Se em comparação com os animais que receberam fontes inorgânicas. A CCS durante os primeiros 80 dias de lactação foi menor (P = 0,056) para o grupo alimentado com Zn, Cu e Se orgânicos. Não foram observados efeitos de fontes orgânicas de Zn, Cu e Se sobre as concentrações de CuZnSOD , GSH-Px e CP, Zn, Cu e Se plasmáticos, produção e composição de leite, consumo de nutrientes, ECC, mudança de ECC e PC. Foi observado efeito (P=0,024) da fonte sobre a mudança de PC. / The general objectives of this study were to evaluate the effect organic zinc (Zn), copper (Cu) and selenium (Se) supplementationto dairy cows on milk quality, mammary gland health and feed intake. The specific objectives were to evaluate: the somatic cell count (SCC), clinical and subclinical mastitis prevalence, milk production and composition during the first 80 days of lactation; the superoxide dismutase (CuZnSOD), glutathione peroxidase (GSH-Px) and ceruloplasmin (CP) enzyme activity; the nutrients intake; Zn, Cu and Se plasmatic concentrations; changes in weight and body condition score. Nineteen dairy cows, with confirmed pregnancy, were selected by body weight (BW), body condition score (BCS), number of lactation, and milk yield in previous lactation, and randomly distributed among two groups to receive organic (n=9) or inorganic (n=10) sources of Zn, Cu and Se. The diets were formulated to meet the nutritional requirements of animals from 60 days before the expected date of calving up to 80 days of lactation. Every day, food samples and leftovers were collected for composition analysis. Milk samples was collected weekly after 15 days of lactation to determine the composition and CCS, on days 1 and 7 of lactation, and when a mastitis clinical case was diagnosed for microbiological culture. Blood samples were collected on -60, -21, 1, 21, 40 and 80 days of the experimental period for CuZnSOD, GSH-Px, and CP analysis. For plasma concentrations of Zn, Cu and Se blood samples were collected at 60 days before calving, and at 1st, 40th and 80th days of lactation. Assessments of body condition score (BCS) and body weight (BW) were performed at the beginning and at the end of the experiment, the day of calving, and once a week throughout the experimental period. The incidence (new cases) and total number of subclinical mastitis cases was lower for the group of cows fed organic Zn, Cu and Se in comparison with animals that received the inorganic sources. The SCC during the first 80 days of lactation was lower (P = 0,056) for the group fed organic Zn, Cu and Se. There were no effects of Zn, Cu and Se organic supply on concentrations of CuZnSOD, GSH-Px and CP, Zn, Cu and Se plasma, production and composition of milk, consumption of nutrients, BW, BCS and changes on BCS. It was observed effect of source on BW changes (P=0,024).

According to the USDA Economic Research service, farm-level prices are on the decline. This decline in prices particularly hurts smaller scale operators with many needing to rely on off-farm income in order to ensure they remain in operation. This thesis studies two problems of key interest to the Southeast region and the State of Kentucky by investigating dairy management practices and the environmental benefits of hemp production. As dairy prices have been on the decline and dairy co-ops have tightened their restrictions on somatic cell count (SCC) levels, dairy farmers and farm managers must decide the best course of action for maintaining milk quality in order to maintain their contract and profitability. Maintenance decisions as well as factors like sanitation and animal living conditions can all contribute to bulk tank SCC and depending on the type of incentives or penalties instituted by the co-op they can have an impact on net farm income. The objective of the dairy study is to determine which dairy management practices have the largest impact on SCC levels. Industrial hemp is produced worldwide. Historically, the major producers of hemp have been China, Europe, and Russia. In 2014, the passage of the Farm Bill opened the door to the production of Industrial hemp through the development of state pilot programs. Then the 2018 Farm Bill removed industrial hemp from the Scheduled Drug list. This has further expanded the opportunities and excitement for this crop. The plant’s versatility and the variety of products that can be made from it are coming to light. Sustainability is one of the key attributes touted concerning industrial hemp. Specifically, in the state of Kentucky, it is expected to be a replacement for tobacco and other traditional crops. However, how does the crop compare to tobacco production in terms of sustainability? The objective of the hemp study is to develop a life cycle analysis on the planting and harvesting of hemp and compare its impacts to more traditional crops.