Doctor of Philosophy / Department of Diagnostic Medicine/Pathobiology / Steven S. Dritz / Vaccination against porcine circovirus type 2 (PCV2) has become a standard practice to improve pig mortality and growth rate in PCV2-affected herds. Unfortunately, there has been little field-based research evaluating factors which affect circovirus vaccination. The focus of this research was on potential vaccination-affecting factors such as age, dosing strategy, pig genetic makeup, and interaction with other vaccines. A total of 6,275 pigs were used to determine factors which affect circovirus vaccination and the effects of vaccination on average daily gain (ADG), immune responses, and viral circulation under field conditions. In the first study evaluating circovirus vaccination effects on PCV2 antibody titer, regardless of age and dose administration protocol, pigs vaccinated with a 2-dose circovirus vaccine had increased (P ≤ 0.008) antibody titers compared with non-vaccinates. In a second study, dosing strategy failed (P = 0.31) to affect antibody titers. However, product and time after vaccination did affect (P = 0.005) antibody titers. In another 130-d study across the nursery and finishing phases, pigs vaccinated with a 2-dose circovirus vaccine had decreased (P < 0.001) serum PCV2 viral load compared with non-vaccinates and ADG of vaccinates was better than non-vaccinates. However, the effect was more pronounced (vaccination-by-genetic interaction, P ≤ 0.05) in Duroc-based compared to Pietrain-based pigs. In a study limited to the nursery phase, vaccination for PCV2 and Mycoplasma hyopneumoniae independently reduced ADG and consumption, but the effect was product-dependent. In a 155-d study across the nursery and finishing phases, vaccination with a 2-dose, 2-vaccine program for PCV2 and Mycoplasma hyopneumoniae decreased (P < 0.001) nursery ADG but tended to increase (P = 0.06) finishing ADG compared to a 1-dose, 2-vaccine program, with no difference (P = 0.66) observed between final pig weights. Finally, circovirus vaccination affected PCV2-circulation in high-health research herds but not in a commercial herd where PCV2 DNA was detected in the environment. These results indicate that finishing performance was improved by a 2-dose circovirus vaccine; however, nursery performance was negatively affected by the same product. Circovirus vaccination responses of growth, viral load, and antibody titer were affected by pig genetic makeup, product, and PCV2-exposure status.

Master of Science / Department of Computing and Information Sciences / William H. Hsu / In addition to named entities such as persons, locations, organizations, and quantities which convey factual information, there are other entities and attributes that relate identifiable objects in the text and can provide valuable additional information. In the field of epizootics, these include specific properties of diseases such as their name, location, species affected, and current confirmation status. These are important for compiling the spatial and temporal statistics and other information needed to track diseases, leading to applications such as detection and prevention of bioterrorism. Toward this objective, we present a system (Rule Based Event Extraction System in Epizootic Domains) that can be used for extracting the infectious disease outbreaks from the unstructured data automatically by using the concept of pattern matching. In addition to extracting events, the components of this system can help provide structured and summarized data that can be used to differentiate confirmed events from suspected events, answer questions regarding when and where the disease was prevalent develop a model for predicting future disease outbreaks, and support visualization using interfaces such as Google Maps. While developing this system, we consider the research issues that include document relevance classification, entity extraction, recognizing the outbreak events in the disease domain and to support the visualization for events. We present a sentence-based event extraction approach for extracting the outbreak events from epizootic domain that has tasks such as extracting the events such as the disease name, location, species, confirmation status, and date; classifying the events into two categories of confirmation status- confirmed or suspected. The present approach shows how confirmation status is important in extracting the disease based events from unstructured data and a pyramid approach using reference summaries is used for evaluating the extracted events.

Master of Science / Department of Animal Sciences and Industry / Terry A. Houser / Two experiments were completed as a part of this study. The objective of the first experiment was to determine the differences in chemical characteristics of trimmings from hot processed and traditionally processed cull meat goats. Crossbred cull doe goats (n=18) were assigned to one of 3 kills days with 6 replications per day. The sides of each goat were randomly assigned to hot processed (HP) or traditionally processed (TP). HP sides were fabricated within 2 h of slaughter, ground with 2% salt and dry ice and then held at 2oC for 24h. TP sides were chilled at 2oC for 24 h prior to fabrication and grinding. After sampling, 2% salt was added to remaining trim yielding 2 treatments: traditionally processed with no salt added (TPNS) and traditionally processed with salt added (TPS). As expected, the HP treatment had a higher (P<0.0001) ultimate pH than TP and a higher water holding capacity (WHC) than TPS (P<0.002) and TPNS (P<0.001) treatments. HP and TPNS had significantly higher (P<0.0007 and P<0.0003, respectively) percent moisture than TPS. Percent fat was similar (P>0.19) for all treatments. However, TPNS had more protein (P<0.0001) than either the HP or TPS treatments. HP and TPS had decreasing L* values until d 6 when values increased significantly while TPNS decreased steadily by day. HP and TPS differed significantly from TPNS until d 6 when no significant differences were seen. For all treatments, a* values showed decreasing values until d 6. For all treatments, b* values increased until d 5. The objective of the second experiment was to investigate the viability of composting as a means for disposing of goat tissues resulting from the slaughter and fabrication process. By-products from the slaughter of cull meat goats (n=18) were assigned to 3 treatment piles: bones, offal + head (OH), and whole (bones, skull, and offal). Bones and OH piles increased in temperature, with peaks at wk 7 and wk 9, while whole piles had elevated temperatures from wk 5 to wk 9. Bone piles had statistically lower temperatures through wk 3, but were not statistically different than other treatments through the duration of the study. Whole piles had higher (P<0.0001) temperatures over the 8 wk composting period than OH and bone piles. Bone decomposition progressed over 90 d; at d 60, bones in whole piles had greater (P<0.05) decomposition than in bone piles. Similarly, skulls decomposition increased over the 90 d period. At d 60 and 90, skulls in whole piles had greater (P<0.05) decomposition than skulls in OH piles.

Master of Science / Department of Animal Sciences and Industry / Duane L. Davis / Intestinal absorption of colostral leukocytes (CL), peripheral blood mononuclear cells (PBMC), and porcine umbilical cord matrix stem cells (PUC) was analyzed in neonatal pigs. Maternal CL have previously been demonstrated in pigs, and maternal PBMC have been observed in calves to enter neonatal circulation after ingestion. PUC are primitive stem cells that are easily isolated from Wharton's jelly of the porcine umbilical cord. These cells do not have an immunogenic effect on the host upon initial transplantation. The general characteristics of PUC may allow them to serve as a delivery system to the neonate. Cellular migration through the duodenum, jejunum, and ileum was assessed using confocal microscopy. In vitro experiments utilized an organ explant culture system to determine the trafficking of labeled cells. Small-intestine tissue was collected from stillborn and sacrificed neonates. All three cell types (CL, PBMC, and PUC) were detected below the luminal surface, after 72 h of culture with media, and regardless of whether explants were from stillborns or live-born pigs. In vivo trafficking was assessed using neonatal pigs that were fed PBMC isolated from their mother or PUC from an unrelated pig. The effect of prior exposure to 25% acellular colostrum (AC) in medium was evaluated for both cell types. Piglets were euthanized 8 h or 24 h post feeding and sections of the small intestine collected. Both PBMC and PUC were found in all intestinal samples. Exposure to AC had no detected effect on the ability of either cell type to attach and migrate into the tissue. Labeled PUC were detected on the surface of the epithelium and in the lamina propria 8 h post treatment. PBMC were observed on the surface of the epithelium, in the lamina propria, and superficial submucosa 8 h following ingestion. In neonates sacrificed 24 h post treatment, both PUC and PBMC were observed on the surface of the epithelium, in the lamina propria, superficial submucosa, and deep submucosa of the small intestine. PUC and PBMC were noted at the apex, intermediate between the apex and the base, or at the base of the villus.

Les objectifs de cette étude ont été de : (1) déterminer s’il existe une association entre la présence intra-utérine d'Escherichia coli dans la 1 ère semaine postpartum et le développement de la métrite postpartum, (2) déterminer s’il y a une association entre les gènes de virulence d'E. coli et la métrite postpartum, et (3) d'évaluer si les analyses bactériologiques (bactéries et gènes de virulence d'E. coli) pourraient prédire la métrite postpartum chez la vache laitière. Des écouvillons utérins ont été prélevés dans la première semaine postpartum sur 486 vaches de race Holstein et soumis au laboratoire pour détection de E. coli. Les gènes de virulence d'E. coli ont été identifiés par la technique d'hybridation des sondes radioactives. Un total de 252 vaches (52%) ont été positives à E. coli et 67 vaches positives à la métrite postpartum (13,7%). Les vaches positives à E. coli intra-utérin dès la première semaine postpartum avaient un risque 2,6 fois plus élevé de développer la métrite postpartum que les vaches sans E. coli. La plupart des E. coli possédaient un ou plusieurs gènes des E. coli d'origine extra-intestinale (ExPEC) dont fimH (89%), HlyE (87%) et iss (70%). Parmi les autres gènes ExPEC, on a retrouvé sitA (23%), fepC (20%) hra1 (20%) malX (14%) tsh (11%) et bien d'autres. Les gènes de virulence kpsMTII et hra1 ont été associés à la métrite postpartum avec un rapport de cote de 4,3 chacun. La présence d'E. coli dans l'utérus avait une valeur prédictive positive de 18% tandis que la présence des gènes kpsMTII et hra1 avait une valeur prédictive positive de 36% et 31% respectivement. La détection de certains gènes de virulence d'E. coli dans les prélèvements utérins pourrait renseigner sur le risque de développement de la métrite postpartum chez la vache laitière. Les études ultérieures pourraient tester encore plus de gènes et viser à développer des tests de dépistage simple, facilement et rapidement applicable à la ferme. / The objectives of this study were to (1) determine whether there is an association between the presence of intra-uterine Escherichia coli in the first week postpartum and the occurrence of postpartum metritis in the subsequent weeks, (2) determine whether there is an association between E. coli virulence genes and postpartum metritis, and (3) to assess whether the presence of these E. coli virulence genes could predict the occurrence of postpartum metritis in dairy cows. Uterine swabs were collected in the first week postpartum from 486 Holstein cows and submitted to the laboratory for detection of E. coli. Virulence genes of E. coli were identified using the radioactive probe hybridization method. A total of 252 cows (52%) were positive for intra-uterine E. coli and 67 cows (13.7%) were positive for postpartum metritis. Cows positive for intra-uterine E. coli in the first week postpartum had 2.6 times the odds of developing postpartum metritis compared to negative cows. Most intra-uterine E. coli possessed one or more ExPEC genes, among which FimH (89%), hlyE (87%), and iss (70%). Other ExPEC genes such as sitA (23%), fePC (20%) hra1 (20%) malX (14%) tsh (11%) and others were found with low prevalence. The presence of the virulence genes kpsMTII and hra1 was associated with 4.3 times each the odds of developing postpartum metritis compared to negative cows. The presence of E. coli in the uterus had a positive predictive value of 18%, while the presence of the genes kpsMTII and hra1 had a positive predictive value of 36% and 31% respectively. The detection of certain virulence genes of E. coli in uterine swabs could inform about the risk of developing postpartum metritis in dairy cattle. Further studies could test more virulence genes and aim at developing molecular tests that would be simple, quickly and easily applicable on farm.

Doctor of Philosophy / Department of Diagnostic Medicine/Pathobiology / Tiruvoor G. Nagaraja / Escherichia coli O157 is a major foodborne pathogen. The bovine gut is the primary reservoir and the organism is shed in the feces, which serves as the major source of contamination. The objectives of our research on E. coli O157 were to 1) determine prevalence and characterize presence in the rectoanal mucosa of cattle, 2) rationalize preferential prevalence in the hindgut, 3) evaluate fecal prevalence and concentration in relation to carcass contamination 4) determine the efficacy of preharvest intervention strategies to reduce fecal prevalence and/or concentration in cattle. We determined that E. coli O157 isolated from the rectoanal mucosa were similar to fecal isolates. We evaluated methods of enumeration in cattle feces to identify fecal samples with > 10[superscript3] and 10[superscript4] CFU of E. coli O157/g. We observed that prevalence of E. coli O157 on carcasses was correlated with high-shedders. We identified gluconic acid as a substrate which stimulates growth of E. coli O157 in fermentations with ruminal microbial or fecal microbial inocula from cattle. This may explain the preference to persist or colonize the hindgut because gluconic acid is a component of colonic mucin. Additionally, we evaluated the effects of cattle diets (two grain types and two grain processing methods), which present different amounts of fermentable starch to the hindgut, on prevalence of E. coli O157. Dry-rolled grain-based diets reduced prevalence of E. coli O157, possibly because of increased flow of starch to the hindgut. Competitive exclusion cultures of E. coli in in vitro fermentations reduced E. coli O157 in ruminal microbial inoculum, but in fecal microbial inoculum cultures were only efficacious when gluconic acid also was added. Lastly, we evaluated a vaccine which targeted the siderophore receptor/porin proteins of E. coli O157. The vaccine reduced prevalence, the total number of days cattle tested positive, and the total number of days cattle were identified as high-shedders of E. coli O157. In summary, our research adds further knowledge to the literature about E. coli O157 in the hindgut, provides methods to identify high-shedding animals, demonstrates the importance of high-shedding animals, and offers information about potential preharvest interventions.

Master of Science / Department of Animal Sciences and Industry / Timothy G. Rozell / Follicle stimulating hormone (FSH) is known as the key hormone capable of causing proliferation of granulosa cells in the ovary. The classical receptor belongs to the G protein-coupled superfamily and is designated FSHR-1. A variant in the FSH receptor has been shown to be functional in mouse ovaries. The variant receptor is designated as FSHR-3, and when bound by FSH activates a pathway that shares similar characteristics to the growth factor type I receptor pathway, with no increase in cAMP. The FSHR-3 variant activates MAPK upon binding to FSH, and causes proliferation of cells on which it is known to be expressed. For example ID8 mouse ovarian surface epithelium cells (MOSEC), a cell line that when introduced in immunocompetent mice causes tumors similar to human ovarian cancer and which also express FSHR-3, proliferated in response to FSH. The present study explored the potential for decreasing expression of FSHR-3 protein. The RNA interference (RNAi) technique was used to insert small inhibitory RNA(siRNA) segments corresponding specifically to the R3 variant of the FSH receptor in ID8 MOSEC. Transfected cells were lysed and FSHR-3 protein was visualized using SDS Page and Western blotting analysis. A reduction in expression of FSHR-3 was observed in two of the transfection groups, with the greatest down-regulation of FSHR-3 being 30.1%. From these preliminary results we conclude that the FSHR-3 is expressed on ID8 cells, and that siRNA may be useful to reduce its expression. Thus, it may be possible to slow the growth of FSH-responsive tumors using siRNA to target the FSHR-3 receptor.

Master of Science / Department of Clinical Sciences / Daniel U. Thomson / Bovine respiratory disease complex (BRDC) is the most common, and costly, disease in feed yard cattle. A review of the literature shows a correlation between the diagnosis of BRDC ante-mortem and respiratory lesions at slaughter. The objectives of the studies reported here were to: 1) validate a thoracic auscultation scoring system by correlating ante-mortem lung sounds with post-mortem lung lesions and 2) evaluate thoracic auscultation and rectal temperature as diagnostic tools to predict case outcome in the feeder cattle treated for BRDC. First, a prospective cohort study involving thirty four head of cattle that had been realized from commercial cattle feeding operations were used to validate the use of a lung auscultation scoring system to identify cattle suffering from BRDC. Ante-mortem auscultation scores were compared to post-mortem lung lesions evaluated using a previously described scoring system. There was a positive correlation (P < .0001) between ante-mortem lung auscultation scores and post-mortem lung lesion scores in the population of feeder cattle that were tested. Subsequently, a retrospective cohort study was conducted using data obtained from three commercial feed yards. Cattle enrolled in the study (n = 4,341 head) were treated for BRDC between January 2007 to October 2007 by trained feed yard personnel. Data recorded included animal identification, rectal temperature, lung score, and antibiotic therapy at first treatment. Treatment outcome data were recorded by feed yard personnel utilizing an animal health computer. The outcome data tracked for this study included subsequent BRDC treatment or death of the animal. Our findings indicated that as lung auscultation score (P < .0001) or rectal temperature (P < .0001) increased there was an increased risk for cattle to require a second BRDC treatment. Also, we observed an increased risk for death loss in cattle with higher lung auscultation scores (P < .0001) or higher rectal temperature (P < .0001) at the time of treatment for BRDC. We have demonstrated that lung auscultation score and rectal temperature can be used as tools to predict treatment outcome in cattle treated for BRDC. Future research with these tools could be used to develop more precise therapeutic protocols for BRDC in feeder cattle.

No description available.

L’évaluation de la condition corporelle des carcasses des bélugas du Saint-Laurent contribue au diagnostic de cause de mortalité du pathologiste. La méthode actuelle repose sur une évaluation visuelle subjective. Notre projet visait à chercher un outil objectif d’évaluation de la condition corporelle. L’indice de masse mise à l’échelle (M̂ i) est objectif puisqu’il est calculé à partir de la masse et de la taille de chaque individu. M̂ i doit être calculé avec des constantes différentes pour les bélugas mesurant plus ou moins de 290 cm. Il produit des résultats en accord avec l’évaluation visuelle. Comme il est parfois logistiquement impossible de peser un béluga, nous avons évalué des indices basés sur d’autres mesures morphométriques. Les indices basés sur la circonférence à hauteur de l’anus pour les bélugas de moins de 290 cm et la circonférence maximale pour ceux de plus de 290 cm représentent des indices de condition corporelle alternatifs intéressants. / Evaluation of the body condition of beluga carcasses from the Estuary of the St. Lawrence contributes to the diagnosis of the cause of death by the pathologist. The current method relies on a subjective visual evaluation. Our project aimed at developing an objective tool for the evaluation of body condition. The Scaled Mass Index (M̂ i) is an objective figure since it is obtained from individual masses and lengths. M̂ i has to be calculated with different constants for belugas under and above a length of 290 cm. M̂ i yielded results consistent with visual evaluation. Since weighing belugas can be logistically impossible, we evaluated indices based on several other morphometric measurements. Indices based on girth at the level of the anus and maximal girth for animals under and above 290 cm, respectively, were deemed useful as alternative body condition indices.