Master of Veterinary Bioscience / Department of Diagnostic Medicine/Pathobiology / Deon Van Der Merwe / Every year thousands of domestic animals are poisoned by ethylene glycol. Exposure is normally orally, but may be dermal, and poisonings are usually accidental and not malicious. Antifreeze, overwhelmingly the source of the ethylene glycol poisoning, is responsible for over 99% of reported cases. Storage, handling and proper disposal of ethylene glycol is extremely important in limiting access to this deadly product. Ethylene glycol exposures were involved in 1737 calls made to the American Society for the Prevention of Cruelty to Animals call center between 2006 and 2011. Dogs were involved in approximately 87% of exposures and cats in 13%. There were no seasonal or breed patterns. The most common clinical signs reported were neurological and gastrointestinal for both cats and dogs. Urinary calcium oxalate crystals were reported in 28.6% of exposed cats, and 21% of dogs. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) was used to detect calcium oxalate crystals in wax-mounted kidneys from twenty total cases, ten of which were suspected ethylene glycol poisoning submitted to the Kansas State Veterinary Diagnostic Laboratory, and ten samples deemed negative by a pathologist using light microscopy. Pure calcium oxalate monohydrate was used as a reference, and a unique absorption peak was detected between wavenumbers 1290 cm[superscript]-1 and 1320 cm[superscript]-1. The drying of kidney tissues resulted in increased sensitivity for calcium oxalate. Crystal detection by the ATR-FTIR was compared to light microscopy. Bi-fringence of crystals allowed microscopic detection, but the ATR-FTIR specificity for the test was 100%, and sensitivity was 80% compared to traditional microscopy for ca-oxalate crystal identification. ATR-FTIR was also used to detect un-metabolized ethylene glycol in vomitus using wavenumbers 1084 cm[superscript]−1, 1039 cm[superscript]−1, and 882 cm[superscript]−1, but ethylene glycol was not detectable. Ethylene glycol concentrations in samples were much too low to be detected as ethylene glycol on the ATR-FTIR, as the limit of detection was not distinguishable until 5000 ppm using a serial dilution. These methods presented simple, reliable, quick, sensitive, stable, and highly adaptable tests for detection, diagnosis and treatment of ethylene glycol poisoning.

Master of Science / Animal Sciences and Industry / Teresa L. Douthit / Abrupt dietary changes increase a horse’s risk for developing gastrointestinal diseases, such as colic or laminitis. Understanding the impact of various feeds and feeding practices on feeding behavior and gastrointestinal function creates a whole-animal perspective that allows for a more holistic interpretation of the effects of abrupt dietary changes on the hindgut environment. Unfortunately, few reports exist that have examined the effects of abrupt dietary changes in the horse. This study was designed to determine the effects of various abrupt dietary changes on the hindgut environment. In 4 sequential experiments, horses were exposed to an abrupt change from a baseline ration to a complete pelleted diet, an abrupt change from a baseline ration to a 100% grass hay diet, an abrupt change from a prairie hay ration to an alfalfa hay ration, and an abrupt change from a baseline ration to a large concentrate meal. These dietary challenges were chosen to mimic real-world scenarios that horse owners are likely to encounter. These experiments were arranged into a longitudinal trial in which the effects of the abrupt dietary change on cecal and fecal pH, total lactate and volatile fatty acid (VFA) concentrations, cecal lactate-utilizing bacterial populations, and fecal dry matter (DM) were compared to values obtained while horses were consuming the baseline diet. In the first experiment, decreased cecal (P ˂ 0.0001) and fecal (P ˂ 0.0001) pH values combined with increased cecal total lactate (P ˂ 0.001) and fecal VFA concentrations (P ˂ 0.0001) indicate that the abrupt change to a complete pelleted diet disrupted the stability of the hindgut environment. Because cecal pH values were below 6.0, this dietary challenge may be significant enough to elicit subclinical fermentative acidosis and, thereby, increase colic risk. The dietary change to grass hay had little impact on the hindgut environment, as pH, total lactate, and VFA concentrations remained stable (P ≥ 0.05). In general, horses may well tolerate an abrupt increase in the fibrous component of the diet and the elimination of concentrate, a dietary shift that presents a more natural diet to the horse. The abrupt change to alfalfa hay elicited alterations in cecal pH (P ˂ 0.01), total lactate (P ˂ 0.0001) and VFA concentrations (P ˂ 0.05), and lactate-utilizing bacterial populations; however, fecal parameters varied little in response to the dietary change (P ≥ 0.05), indicating that the distal hindgut may be more tolerant to abrupt changes in forage sources than the cecal environment. Here, the potentially adverse shifts in cecal parameters indicate that an abrupt change in hay type and quality alters the fermentative environment of the proximal hindgut and may increase a horse’s risk for gastrointestinal disease. Similarly, the abrupt introduction of a large concentrate meal elicited a decrease in cecal pH (P ˂ 0.005) along with increases in total lactate (P ˂ 0.001) and VFA concentrations (P ˂ 0.05) in the cecum that were consistent with previously reported experiments in which horses were presented with large increases in dietary concentrates. Notable shifts in lactate-utilizing bacterial growth curves were also observed. Overall, these results provide evidence of environmental alterations in the equine hindgut that support epidemiological reports that associate abrupt changes in the amount and type of concentrate, hay type and quality, and forage:concentrate ratio with increased risk for gastrointestinal disease in horses.

Master of Science in Biomedical Sciences / Diagnostic Medicine/Pathobiology / Daniel U. Thomson / Auction derived feeder calves (n=1,601; initial BW = 273.5 ± 4.7 kg) were used to examine the effects of delayed administration of the initial steroid implant on health, performance, and carcass characteristics of feedlot cattle. Steers were procured from multiple-source auction markets in the southeastern United States and shipped to a central Kansas feedyard over a 6 week period from December 2009 to January 2010. Steers were rested overnight prior to processing, then were randomly assigned, within arrival block, to 1 of 2 treatments: 1) implanted with Revalor-XS (40 mg estradiol and 200 mg trenbolone acetate) immediately upon arrival (ARRIVAL); or 2) implanted with the same implant after 45 d (DELAYED). Cattle were weighed on a group scale immediately following processing of each block. Feed deliveries were measured using load cells on feed trucks and recorded daily. Cattle were evaluated daily for morbidity and mortality by trained feedyard health personnel. Sick or injured cattle were removed from the home pen for further diagnosis and treatment. Individual animal health data were obtained and recorded daily. Final BW was calculated by dividing HCW by the average dressing percent of the pen. Carcass data (quality grade and yield grade) were obtained by USDA personnel; presence of lung lesions, pleural adhesions, and liver abscesses was evaluated by trained university personnel. Delaying the initial implant tended to reduce morbidity (24.7 vs. 28.5%; P = 0.13) and reduced railer rates (1.8 vs. 3.3%; P = 0.02); however, there were no effects of timing of implant administration (P ≥ 0.31) on rates of retreatment, mortality, lung lesions, or pleural adhesions. Implanting immediately upon feedlot arrival resulted in numerical improvements in ADG and feed conversion, but these differences were not statistical (P ≥ 0.56). Cattle implanted upon arrival had numerically greater HCW and yield grade vs. cattle implanted on d 45; however, these differences were not statistical (P ≥ 0.16). Delaying the initial implant 45 d did not influence animal health, performance parameters or carcass characteristics in high risk feeder calves.

Master of Science / Clinical Sciences / Daniel U. Thomson / Consumer interest in production agriculture has prompted the beef industry to develop tools to increase accountability of producers for animal management practices. The Beef Quality Assurance Feedyard Assessment, developed by veterinarians, animal scientists, and production specialists, was used to objectively evaluate key areas of beef cattle production such as animal handling, antimicrobial residue avoidance, and cattle comfort in 56 Kansas feedyards. During the assessment, management protocols were reviewed, facilities and pens were inspected, and cattle handling practices were observed. Of the 56 feedyards, 19 maintained complete and current Best Management Practices documentation for all management protocols required by the assessment. During assessment of cattle handling practices, 78.6% of feedyards met requirements for an Acceptable score for all measured criteria. An electric prod was used on only 4.0% of cattle during processing. In addition, 83.0% of feedyards scored Acceptable for stocking rate, feed bunk, water tank, and mud score standards.

Doctor of Philosophy / Department of Animal Sciences and Industry / Joe D. Hancock / Twelve experiments were completed to evaluate corn- and sorghum-distillers dried grains with solubles (DDGS) in diets for nursery and finishing pigs. In Exp. 1, corn-DDGS had 223 kcal/kg greater DE than sorghum-DDGS (P<0.02). In Exp. 2, pigs fed a corn-soy control diet had greater ADG, nutrient digestibility, HCW, and dressing percentage (P<0.02) and lower iodine value (IV) of jowl fat (P<0.001) than pigs fed diets with 40% DDGS. High-energy DDGS supported lower ADG, ADFI, and digestibility of DM (P<0.06) than moderate-energy DDGS, and sorghum-DDGS resulted in lower IV than corn-DDGS (P<0.001). In Exp. 3 and 4, addition of sodium bicarbonate to adjust dietary pH and electrolyte balance did not improve growth performance in nursery or finishing pigs (P>0.16) and adding molasses to improve palatability decreased (P<0.05) G:F for finishing gilts. In Exp. 5 and 6, enzyme additions improved nutrient digestibility in nursery (P<0.04) and finishing (P<0.01) pigs fed diets with high inclusion of DDGS. In Exp. 7, expander processing improved (P<0.02) ADG, G:F, and digestibility of DM, N, GE, and cellulose compared with standard steam conditioning of diets for nursery pigs, with the greatest response in G:F for pigs fed sorghum-DDGS (DDGS source × conditioning; P<0.02). In Exp. 8 and 9, expander conditioning improved G:F and dressing percentage (P<0.007) and digestibility of DM, N, and GE compared with standard conditioning (P<0.02), with the greatest response in digestibility of DM for the DDGS diets (diet × conditioning, P<0.01). In Exp. 10, 11, and 12, increasing tallow from 0 to 5% in diets with 40% DDGS improved (P<0.05) G:F. Dressing percentage was improved with addition of tallow and palm oil (P<0.08), but IV become worse (linear, P<0.06) as tallow was increased in the diet. Adding coconut oil improved growth performance and carcass firmness in pigs fed diets with 40% DDGS (P<0.01). In conclusion, growth performance and nutrient digestibility decreased with addition of DDGS to diets for nursery and finishing pigs. However, adding enzymes partially restored nutrient digestibility; expander conditioning improved G:F, dressing percentage, and nutrient digestibility; and adding coconut oil to diets with 40% DDGS improved G:F and carcass firmness.

Master of Science / Department of Grain Science and Industry / Leland McKinney / Carryover of medicated feed additives between batches of feed can potentially result in harmful drug residues in the edible tissues of food-animals. Flushing the equipment with an ingredient, such as ground grain, is one method used to remove any residual medicated feed from the system. It is generally recommended that the quantity of flush used be between 5 and 10% of the mixer's capacity. However, there is little data that supports this recommendation. Therefore, two experiments were conducted to 1.)determine which manufacturing equipment is the major source of carryover, 2.)evaluate which flush size adequately prevents drug carryover, and 3.) quantify the interrelationship between flush size and drug concentration. In Experiment 1, feed medicated with nicarbazin (Nicarb 25%®; 0.0125%) was manufactured and conveyed from the mixer, through a drag conveyor and bucket elevator, and then into a finished product bin. The system was then flushed using ground corn in the amount of 2.5, 5, 10, 15, or 20% of the mixer's capacity (454.5 kg). Subsequently, a non-medicated diet was conveyed through the system and samples were collected and analyzed for nicarbazin. No significant (P > 0.05) differences were detected among the flush treatments, and all treatments were effective in preventing nicarbazin carryover to the non-medicated diet. In Experiment 2, feed medicated with three levels of monensin (Rumensin® 80; 100, 600, and 1,200 g/ton) was manufactured and handled in the same manner as in Experiment 1. The flushing treatments examined were: 1, 2.5, and 5% of the mixer's capacity. Samples of the non-medicated diet for each treatment were collected and analyzed for monensin. There was significant interaction (P < 0.05)between drug level and sampling location between treatments. As the drug level in the medicated diet increased, higher concentrations of monensin were detected in the non-medicated diet. Collectively, these studies demonstrate that a 2.5%, even a 1% flush size, is effective in preventing carryover of medicated feed additives. It was also demonstrated that the bucket elevator and finished product bin were the major sources of drug carryover in this particular feed manufacturing system.

Master of Science / Department of Animal Sciences and Industry / Dale A. Blasi / An experiment was conducted to evaluate the effects of dry matter intake (DMI) restriction on early receiving performance by steers in a drylot and subsequent grazing performance, feedlot performance, and carcass characteristics. During the backgrounding period, crossbred, weanling steers (n = 329; initial BW = 191± 5.52 kg ) were randomly assigned to 1 of 4 DMI levels corresponding to ad libitum, 2.50% of BW (2.50%), 2.25% of BW (2.25%), and 2.00% of BW (2.00%) for 62 d. During the subsequent grazing period, the same steers were randomly assigned to 13 paddocks to graze for 90 d. Paddocks were stocked at 281 kg live weight per hectare. Initial steer BW were similar on each pasture and each backgrounding treatment was equally represented within a paddock. During the feedlot period, steers were finished at a commercial feedlot and were assigned to 1 of 4 pens according to their rank in BW. Entire pens were harvested when average steer BW reached 545 kg. During the backgrounding period, ad libitum-fed steers had greater (P < 0.001) ADG and final BW than other treatments; steers fed at 2.50 and 2.25% of BW had similar ADG and final BW and were greater (P < 0.001) than steers fed 2.00% of BW. During the grazing period, compensatory gain was observed in restricted DMI treatments. Steers fed at 2.00% of BW had greater (P = 0.006) ADG than ad libitum-fed steers but an ADG similar to that of the other restricted DMI treatments. Steers fed ad libitum, 2.50% of BW, and 2.25% of BW had similar final BW and steers fed 2.00% of BW had lesser (P < 0.001) final BW than other treatments. During the feedlot phase, steers fed 2.00% of BW were on feed longer (P < 0.05) than other treatments. Growth compensation during grazing illustrated that restricted feeding immediately prior to pasture grazing can reduce backgrounding costs.

Master of Science / Department of Animal Sciences and Industry / Duane L. Davis / The three transcription factors, Nanog, Oct-4 and Sox-2, are central regulators of pluripotency in embryonic stem cells. Porcine umbilical cord (PUC) matrix stem cells also express these transcription factors. Wharton’s jelly is composed of an extracellular matrix high in hyaluronic acid and various collagens and serves as a reservoir for several growth factors and cytokines. We expect that Wharton’s jelly includes a stem cell niche that provides a microenvironment that maintains and supports the stem-cell characteristics of PUCs. The mechanisms by which the PUCs remain primitive within the Wharton’s jelly are unknown. We developed methods for producing an extracellular matrix product extracted from porcine Wharton’s jelly that we named Pormatrix (PMX). When PMX is incubated at 37[degrees]C, it becomes a matrical gel that provides a matrix allowing PUC attachment and growth. Concentrating the protein in PMX by filtration provides a low molecular weight by-product which we refer to as flow through (FT). In Experiment 1, PUCs were seeded on Pormatrix, Matrigel or plastic substrates in the presence or absence of FT. PUCs cultured on Matrigel, Matrigel+FT, Plastic+FT and PMX had higher expression of Nanog compared to PUCs cultured on PMX+FT (P-value <0.05). In Experiment 2, the PMX and Matrigel were diluted to low protein concentrations (1.2-1.5 mg/ml protein) so that gelling did not occur. Adding FT to PMX, Matrigel and plastic increased gene expression of Nanog 2.78 fold compared to treatments without FT (P =0.10). Sox-2 expression was increased by adding FT to Matrigel but adding FT to the other matrix proteins had no effect resulting in a tendency for a matrix*FT interaction(P=0.10). The transcription factor Oct-4 remained unchanged regardless of treatment. To evaluate the effects of in vitro maintenance on Nanog, Oct-4 and Sox-2 we measured the relative gene expression in PUCs over the first six passages in vitro. Nanog, Oct-4 and Sox-2 did not differ over these passages. This may indicate that during the first six passages in vitro, PUCs remain relatively primitive. In summary, we prepared an extract from Wharton’s jelly from porcine umbilical cords. The extract supported PUC attachment and growth and appeared to regulate gene expression. Perhaps with further investigation the interactions of PUCs with their in vivo environment can be elucidated.

Doctor of Philosophy / Department of Animal Sciences and Industry / Bradley J. Johnson / Zilpaterol (ZIL) is a β-adrenergic receptor (β-AR) agonist that has been recently approved for use in feedlot cattle to improve production efficiencies and animal performance. One of the mechanisms through which this occurs is increased skeletal muscle growth. Therefore, two experiments were conducted to determine the effects of ZIL both in vivo and in vitro. In the first experiment, ZIL addition to bovine satellite cells resulted in a tendency to increase IGF-I mRNA and increased myosin heavy chain IIA (MHC) mRNA with 0.001 [micro symbol]M and decreased MHC mRNA with 0.01 and 10 [micro symbol]M. There were no effects of ZIL on protein synthesis or degradation. In myoblast cultures, there was a decrease in all three β-AR mRNA, and this was also reported in western blot analysis with a reduction in β2-AR expression due to ZIL treatment. In myotubes, there was an increase in β2-AR protein expression. In the second and third experiment, ZIL improved performance and carcass characteristics of feedlot steers and heifers. Additionally, ZIL decreased MHC IIA mRNA in semimembranosus muscle tissue collected from both steers and heifers. An additional part of the third study was conducted to determine the effects of melengestrol acetate (MGA) on bovine satellite cell and semimembranosus muscle gene expression. There were no effects of MGA on the expression of genes analyzed from semimembranosus muscle tissue collected. However, the addition of MGA to cultured bovine satellite cells resulted in increased β1 and β2-AR mRNA. These experiments aid in our understanding of the mechanism of action of MGA in heifers, as well as the effects of ZIL on both steers and heifers. Furthermore, they increase our knowledge and understanding of the mechanism of action of ZIL, as well as other β-agonists used to promote growth and efficiency in feedlot animals.

Master of Science / Department of Diagnostic Medicine/Pathobiology / Larry C. Hollis / Mark F. Spire / Two studies were undertaken to evaluate the use of Near Infrared Spectroscopy (NIRS) to determine arterial oxygen saturation (StO[subscript]2) in cattle with naturally-occurring Undifferentiated Bovine Respiratory Disease (UBRD) and experimentally-induced UBRD utilizing Mannheimia haemolytica. The first study was a natural infection model utilizing 679 beef heifers weighing approximately 227 kg (500 pounds) originating from a southeastern U.S. salebarn. Heifers were evaluated for UBRD upon feedlot arrival, at revaccination, at day 35 on feed, at re-implant time, and two weeks prior to shipment for slaughter. Animals deemed to have UBRD were treated for UBRD and data was collected for 5 days following treatment, while a comparable healthy cohort was also evaluated at the time of treatment. There was a trend for NIRS to be able to predict the incidence of subsequent UBRD when cattle were evaluated on arrival (p=0.0552). However, the ability to detect UBRD in clinically ill cattle was not significantly different (p>0.1690) when compared to healthy cohorts in this model. When carcass characteristics were evaluated at each time point, NIRS StO[subscript]2 values were able to differentiate between yield grades of animals with UBRD and healthy cohorts when evaluated at revaccination, day 35, re-implant, and pre-shipping (p<0.0199). NIRS tended to be able to differentiate yield grades at initial processing (p=0.0513). StO[subscript]2 was not a predictor of quality grade at any time point (p>0.1023), nor was there any correlation between lung lesions at slaughter and StO[subscript]2 (p>0.2292). The second study involved 12 head of 181 kg (400 pound) heifers which were subjected to an experimental challenge model of Mannheimia haemolytica. Animals were evaluated daily and StO[subscript]2 readings recorded 12 hours pre-inoculation, at inoculation, 6, 12 and 24 hours post inoculation and daily for the next 12 days. While NIRS could not definitively differentiate healthy cohort cattle from challenge cattle (p>0.0713), there were trends toward challenge cattle having lower StO[subscript]2 values than healthy controls. The authors conclude that while these studies did not provide conclusive evidence of the ability of NIRS to detect UBRD, further studies with a machine that is specifically calibrated and designed for use with cattle should be performed.