Master of Science / Biomedical Sciences / Daniel U. Thomson / Two studies were conducted to evaluate two animal welfare issues in the beef industry today. The welfare of animals has become a major discussion among consumers and producers. The objective of these studies was to evaluate if certain production practices are beneficial to the wellbeing of the animals in a production setting. The first study evaluated if castration and implementation of growth promotion technologies of physically mature male beef cattle, which failed the breed soundness exam (BSE), improved carcass quality compared to male beef cattle left intact. Sixteen month old Angus bulls (n = 24; 606 + 11.4 kg) were stratified by weight and randomly assigned to 2 treatments: intact control (BULL) and castrated with growth promotion technology (STR) to evaluate performance and carcass quality. Cattle assigned to STR treatment were implanted with 120 mg trenbolone acetate (TBA) and 24 mg estradiol on d 0, and were fed ractopamine hydrochloride (300 mg/d) the final 28 d prior to slaughter. Cattle were fed a dry-rolled corn-based finishing diet (1.41 Mcal/kg NEg) for 62 d (final wt = 697 +/- 24.3 kg) then harvested at a commercial abattoir. Carcass characteristics were recorded and longissimus muscle samples were obtained. There were no differences between treatments for quality grade, yield grade, HCW, back fat thickness, or dressing percent. Steak tenderness values based on Warner Bratzler shear force (WBSF), and sensory panel evaluation showed no difference between BULL and STR steaks in myofibrillar tenderness, juiciness, beef flavor intensity, connective tissue, overall tenderness, and off flavor intensity. Cattle within the BULL treatment tended to have improved average daily gain (ADG) and feed efficiency, with no difference in carcass characteristics, WBSF, or sensory panel measurements compared to STR administered growth promotion technology. The second study evaluated if cohorts with horns within a pen lot of cattle caused an increase in carcass bruising, and to determine if horn tipping and dehorning is necessary. Carcasses from (n = 4,287) feedlot cattle were observed at one commercial beef packing plant in southwest Kansas to investigate the relationship between the presence and size of horns in cattle and the prevalence, anatomical location, and severity of bruising of carcasses. Horn measurements taken were the length of the longest horn from base to tip and the tip-to-tip distance between the tips of both horns. Bruises were evaluated by location and severity. Bruise severity was scored at 3 levels: minor: ≤ 5 cm, moderate: 5 to 15 cm, and severe: > 15 cm. Within pen lots of cattle, the percentage of cattle with horns ranged from 0 to 26%. There were 4,287 carcasses evaluated and 2,295 had one or more bruises for a total, overall bruise prevalence of 53.5%. Of the total number of bruises, 25.6% were severe, 35.6% were moderate, and 38.8% were minor. The majority of bruises (61.8%) occurred on the dorsal mid-line with similar rates of bruising occurring on the left (18.6%) and right (19.5%) sides. There was no relationship found between the prevalence of horns and prevalence of bruising in a pen lot of cattle (P = 0.90). These two studies conclude that feeding of bulls that fail the BSE could eliminate an animal welfare concern while removing the cost and management of growth promotion technology administration. Additionally to that there may be other factors causing carcass bruising at other than cohorts with horns.

Master of Science / Department of Clinical Sciences / Bradley J. White / Castration and dehorning are common husbandry practices in the United States. The objective of this research was to evaluate behavioral responses to these painful procedures. Two studies were conducted using three dimensional accelerometers to measure behavioral differences in cattle following dehorning and castration. The first study evaluated the potential of different analgesics to mitigate pain following castration and dehorning compared to negative controls as judged by behavioral measures. Holstein-Fresian calves given one of three different analgesic protocols (sodium salicylate, a combination of xylazine, ketamine and butorphanol, and both treatments together) or received no analgesia. All cattle were surgically castrated and dehorned. All treatment groups spent more time lying down and less time walking in the post-surgery than pre-surgery, and significant interactions were found between treatment and time relative to surgery (P<0.05). The second study evaluated behavioral changes following castration and dehorning performed independently or concurrently when compared to a negative control (no surgery). Accelerometers recorded behavior in Holstein-Fresian calves in which differing surgical procedures were performed: castration only (CO), dehorning only (DO), castration and dehorning (CD), and no surgical procedure performed (CON). Behavioral data was measured for 6 days following surgery. Significant interactions were found between treatment and time (P<0.05) in both walking and lying behavior. Calves that were dehorned and castrated spent less time walking one day after the procedure compared to controls, but very few other behavioral differences were identified. These studies illustrate that cattle behavior changes following painful procedures such as castration and dehorning.

Master of Science / Department of Clinical Sciences / Daniel Thomson / A total of 400 head of naturally parasitized commercial feedyard cattle (subset of 40 hd/pen; 10 pens) were utilized to compare trade name ivermectin pour-on and a generic ivermectin pour-on. The efficacy of each product was measured by obtaining rectal fecal egg counts on day 0 and day 14 using a Modified Wisconsin sugar float with centrifugation from rectal fecal samples and calculating fecal egg reduction post treatment. There were no differences in net egg count reduction between treatments (P= 0.15) at 14 days post-treatment application. Regardless of treatment, only 26% of animals had a fecal egg count reduction of >90% and only 35% achieved a FECR of >80% which is low considering 90% reduction is the accepted efficacy level. Cattle treated with the generic pour-on had improved average daily gains (ADG) compared to cattle treated with the trade name pour-on P = 0.02. This study demonstrated decreased efficacy of both products with a FECR of less than 90% within a commercial feedyard environment.

Master of Science / Department of Clinical Sciences / Walter C. Renberg / Objective: To compare the in vitro elution characteristics of six common analgesic medications from a commercially available absorbable gelatin sponge. Study Design: Experimental study. Methods: Gelatin sponges were loaded with various analgesic medications, including two opioids, preservative-free morphine and fentanyl, two local anesthestics, bupivacaine and lidocaine, and two α2-adrenergic agonists, dexmedetomidine and xylazine. The loaded sponges were placed in dishes containing phosphate-buffered saline (PBS) and maintained at 37° C with constant agitation. Concentrations of each drug were determined at various time points up to 24 hours post-inoculation using high-pressure liquid chromatography. Two phases were conducted, utilizing undried loaded sponges (phase one) and dried loaded sponges (phase two). Results: In both phases, all analgesic medications eluted from the gelatin sponge and equilibrated rapidly with the PBS, achieving maximal concentration within 30 minutes. In phase two, the rapid nature of the release was captured by increasing sampling within the initial 30 minutes. Results were consistent for each medication with minimal variation. Steady state concentrations were significantly higher in phase two with four out of six medications. Conclusions: Analgesic medication elution from an absorbable gelatin sponge was rapid and consistent. Drying the loaded sponge prior to use will likely substantially increase the amount of medication eluted but not prolong release. Clinical Relevance: The rapid release of analgesic medications from the gelatin sponge makes a prolonged analgesic effect unlikely without further modification. Toxicity may be a concern. Further study is required to investigate efficacy in vivo, safe dosing regimens and prolongation of duration of action.

Master of Science / Department of Clinical Sciences / Amy Rankin / Objective- The purpose was to compare the efficacy and duration of 0.5% proparacaine, 0.5% bupivacaine, 2% lidocaine, and 2% mepivacaine on corneal sensitivity in clinically normal horses. Animals- 68 clinically normal horses Procedures- In group 1, 60 horses from the Kansas State University horse unit were assigned to receive one topical anesthetic in a completely randomized design. In group 2, 8 privately owned horses were sequentially treated with each of the topical anesthetics in random order with a one week washout period between drugs. Corneal sensitivity was assessed by corneal touch threshold (CTT) measurements which were taken with a Cochet-Bonnet aesthesiometer before anesthetic application (T0), 1 minute after (T1), every 5 minutes until 60 minutes (T5-T60), and then every 10 minutes until 90 minutes (T70-T90) after application. General linear mixed models were fitted to CTT in each design in order to assess the effects of topical anesthetics over time, accounting for repeated observations within individual horses. Results- Corneal sensitivity, as determined by CTT measurements, decreased immediately following application of the topical anesthetic, with persisting effects until T35 for proparacaine and mepivacaine, T45 for lidocaine, and T60 for bupivacaine. Maximal CTT reduction was achieved following application of bupivacaine or proparacaine, while mepivacaine was least effective. Conclusions and Clinical Relevance- All topical anesthetics reduced corneal sensitivity, though maximal anesthesia and effect of duration differed between drugs. For brief corneal anesthesia, 0.5% proparacaine or 2% lidocaine appeared adequate, while 0.5% bupivacaine may be most appropriate for procedures requiring longer periods of corneal anesthesia.

Master of Science / Department of Anatomy and Physiology / Mark Weiss / Artificial insemination and cryopreservation of sperm are important components of any transgenic animal facility because they allow for the reduction in animal colony size and the safe storage of germplasm from valuable strains. In addition, they allow long-term storage of these strains and easy transportation of the genetic material to other research facilities internationally. Thus far, only one laboratory has created live rat pups after sperm cryopreservation and intrauterine insemination. Another laboratory made advances in cryopreservation media that improved sperm motility post-thawing, but no pups resulted from this work. In my study, these two cryopreservation media were utilized to perform intrauterine inseminations with both fresh samples of rat sperm as well as samples that were cryopreserved in liquid nitrogen to replicate and extend these studies. Pharmacoejaculation was tested as a means to obtain spermatozoa without euthanizing the male to collect the epididymis, but results were inconsistent and the samples were not useful for intrauterine inseminations or cryopreservation. Epidiymal sperm was then collected into the various media and frozen in liquid nitrogen. In my hands, the frozen/thawed rat sperm achieved motility of less than 1%. Next, the impact of altering the freezing rate on sperm motility was evaluated. Epididymal sperm was collected and processed using a modified protocol and were then frozen at 2, 4 or 6 cm above the level of liquid nitrogen. Four to six days after freezing, samples were thawed and post-thaw sperm motility was evaluated. Sperm motility was measured prior to freezing as well as after-thawing. The sperm motility was correlated with LIVE/DEAD® staining. Sperm motility did not differ between the groups as a result of the freezing rate (Friedman test p=0.23). The published techniques are not robust and require further development to improve the motility of rat sperm after cryopreservation and achieve pregnancy via intrauterine insemination.

Master of Science / Department of Diagnostic Medicine and Pathobiology / Raymond R. R. Rowland / Three economically important swine diseases: Porcine Reproductive and Respiratory Syndrome (PRRS), Porcine Circovirus Associated Disease (PCVAD) and Swine influenza cost the US swine industry more than a billion dollars each year. This study developed a fluorescent microsphere immunoassay (FMIA) to simultaneously detect antibodies to the causative pathogens: PRRSV, porcine circovirus (PCV2) and swine influenza virus (SIV). The results showed that the multiplex assay possessed the predicted specificities. In the case of PRRSV NA, the assay displayed higher sensitivity when compared to a commercially available ELISA. The assay was employed to measure both IgG and IgM responses. The FMIA was found to possess several advantages over standard ELISA which include reduced sample volume, time and cost and provides a new tool for veterinary diagnostics. The FMIA was applied for swine disease surveillance in Hawaiian and Texan feral swine populations. The antibodies against PCV2 showed the highest prevalence among these three pathogens in both Hawaii and Texas. Hence we consider PCV2 as the most prevalent pathogen in Hawaiian and Texan feral pigs and this pathogen poses the greatest threat to commercial pigs. SIV seroprevelance increased from 2007 to 2010 in Hawaii State, suggesting an increasing risk for commercial pigs. Moreover, yearly surveillance in Texas State shows growth in seropositive response to all pathogens, particularly PCV2. The development of FMIA for detection of antibodies to multiple swine pathogens in serum samples offers an important alternative for swine disease surveillance in commercial and feral herds.

Doctor of Philosophy / Department of Diagnostic Medicine and Pathobiology / Brad J. White and Robert L. Larson / Bovine respiratory disease (BRD) is the most costly disease of cattle in US feedyards and diagnosis based on clinical signs of illness is challenging. Over the course of five independent studies we evaluated the precision of multiple observers assigning clinical illness scores (CIS) to calves with induced Mycoplasma bovis pneumonia. We also evaluated the accuracy of CIS in relation to lung lesions at necropsy. Agreement among observers over all five studies was slight ({kappa]= 0.16; 95% confidence interval, 0.10 to 0.24) and ranged from 0.10 to 0.21 for individual trials. The accuracy of CIS varied based on the pulmonary consolidation score chosen to represent a truly ill animal. Inflammation associated with BRD can lead to significant pulmonary damage and reduced lung function. Treatment for BRD frequently involves antimicrobial administration and occasionally non-steroidal anti-inflammatory drugs. We evaluated how calves experimentally challenged with Mannheimia haemolytica respond to treatment with flunixin meglumine, alone or in combination with the antimicrobial florfenicol. Individual calf response to bacterial pneumonia was highly variable in this study. None of the changes in serum biomarkers, CBC or chemistry parameters provided reliable indicators of the pulmonary inflammation associated with the mild severity of bronchopneumonia in our study. Metaphylaxis is frequently administered to manage the risk of BRD within cohorts of cattle. We evaluated the impact of metaphylactic antimicrobial administration 10 days prior to experimental Mannheimia haemolytica inoculation to mitigate pulmonary lesions. We found that calves receiving tildipirosin had less lung damage and fewer clinical signs of illness compared to calves treated with tulathromycin or saline. Finally, the ability to predict those animals that would not finish the production cycle normally would provide benefits in effectively managing cattle. We evaluated the ability of classification algorithms to accurately predict an individual calf’s outcome based on data available at first identification of and treatment for BRD. We found accuracy of classifiers was dependent on the data recorded by the feedyard and there are sub-groups of calves within feedyard populations where classifiers were highly accurate. These data suggest the importance of pairing the proper classifier with the data available.

Doctor of Philosophy / Department of Anatomy and Physiology / Jishu Shi / Porcine reproductive and respiratory syndrome (PRRS) is one of the most economically important swine diseases worldwide that leads to severe reproductive failure in sows and high mortality in young pigs. Vaccination is currently the most effective way to control this disease. The protection ability provided by vaccines however is limited due to the large diversity of field PRRSV strains. In chapter 2, we compared immune responses induced by vaccination and/or PRRSV infection by using IngelVac® Modified Live PRRSV vaccine (MLV), its parental strain VR-2332, and the heterologous KS-06 strain. Our results showed that MLV provide complete protection to homologous virus and partial protection to heterologous challenge. The protection was associated with the levels of PRRSV neutralizing antibodies at the time of challenge. Besides developing new vaccines to combat PRRSV, adjuvants have been applied to PRRSV MLV vaccines to induce vaccination-mediated cross-protection against genetically dissimilar PRRSV strains. In chapter 3, we demonstrated that a commercial MontanideTM Gel01ST adjuvant provides enhanced protection to homologous PRRSV infection by regulating the production of PRRSV-specific antibodies. In chapter 4, we tested a novel peptide nanofiber hydrogel acting as a potent adjuvant for PRRSV MLV vaccines. We found that the hydrogel adjuvant enhanced vaccine efficacy by developing of higher titers of neutralizing antibodies and stronger IFN-γ cellular immune responses. Chinese highly pathogenic PRRSV (HP-PRRSV) variants were isolated in 2006 and they belong to genotype 2 of PRRSV. Compared with classic PRRSV, HP-PRRSV is characterized by robust proliferation ability and high morbidity/mortality with all ages of pigs. In chapter 5, we compared the difference of immune responses elicited by HV-PRRSV, a Chinese HP-PRRSV, and a US virulent strain of PRRSV NADC-20. Traditional PRRSV MLV vaccines developed in US offer no protection to HP-PRRSV. Vaccines specific to HP-PRRSV strains available in China provide protection to HP-PRRSV. In chapter 6, we demonstrated that pigs challenged with US NADC-20 strain were protected by vaccination with Chinese MLV HP-PRRSV vaccines. The availability of Chinese HP-PRRSV vaccines in North America may act to increase the preparedness of possible transmission of HP-PRRSV to North America.

Master of Science / Department of Clinical Sciences / Warren L. Beard / The flexion test is routinely used in lameness and pre-purchase examinations. There is no accepted standard for duration of flexion or evidence that interpretation of results would differ with different durations of flexion. We hypothesized there would be no difference in interpretation of full hindlimb flexion for 5 or 60 seconds. Video recordings of lameness examinations of 34 client owned horses were performed that included: baseline lameness, upper hindlimb flexion for 60 seconds, and flexion of the same leg for 5 seconds. Videos were edited to blind reviewers to the hypothesis being tested. The baseline lameness video from each horse was paired with each flexion to make 2 pairs of videos for each case. Twenty video pairs were repeated to assess intra-observer repeatability. Fifteen experienced clinicians reviewed the videos and graded the response to flexion as either positive or negative. Potential associations between the duration of flexion and the likelihood of a positive flexion test were evaluated using generalized linear mixed models. A kappa value was calculated to assess the degree of intra-observer agreement on the repeated videos. Full hindlimb flexion of 60 seconds was more likely to be called positive than flexion of 5 seconds (p<0.0001), with the likelihood of the same interpretation 74% of the time. The first flexion performed was more likely to be called positive than subsequent flexions (p=0.029). Intra-assessor agreement averaged 75% with κ=0.49. Full hindlimb flexion of a horse for 5 seconds did not yield the same result as 60 seconds.