Master of Science / Food Science / Edgar Chambers IV / Palatability of pet foods is judged by the use of animals in colonies. Pet food manufacturers would like to understand how palatable a food is compared to another food. This generally is accomplished by a two pan test where a pet has the opportunity to freely choose between two foods. Preference is evaluated through the use of an intake ratio, the ratio of the amount of test food consumed divided by the total amount of the foods consumed. Although this is easy to do in laboratories, another option would be to do such studies with animals in more ‘real-life’ home environments. The purpose of this study was to develop, and test a method to capture feeding information from a study of canines in the home environment and analyze the results of the palatability tests. Individual dog owners were screened for information on the household and pets. Twenty-five dogs of different ages, breeds and sizes were selected to participate on the in-home panel. Seven different palatability tests were performed using the in-home panel with four of those tests being replicated; a total of 11 comparative tests. These dogs were tested using a proprietary computer-based technology that collected information about intake of each food for each individual dog for a duration of seven days for each of the 11 comparative studies. Data was analyzed and resulted in showing that differences between foods can be found. Statistical analyses compared initial day one data to subsequent day data collected during each study to determine whether a full seven day test was needed. In addition, comparisons were made to compare the impact of prior foods eaten to subsequent preferences of the dogs. Results of the in-home panel were the same on day one as for all seven days of testing. Also, previous exposure to a food did not alter subsequent preference for that food. Such data has implications for pet food manufacturers related to timing and cost of testing.

Master of Science / Department of Animal Sciences and Industry / Duane L. Davis / Culturing stem cells is usually done on tissue-culture treated plastic. Over time the cells change their gene expression and start to differentiate. Porcine umbilical cord (PUC) stem cells express the embryonic transcription factors Oct4, Nanog and Sox2 and changes in their expression may be useful for to evaluating culture-induced changes in the cells. We developed an extract of porcine Wharton’s jelly matrix (JMX) that may provide some characteristics of the stem cell niche located in the umbilical cord. Our extract used whole cords and enzyme digestion to simplify preparation of the product. We compare cells cultured on plastic to those grown on thin and thick gels of JMX in four experiments. In Exp 1a and b, growing PUCs on a thick JMX coating for 3(1a) or 4(1b) d increased the number of cells at the end of culture (P < 0.05) with minimal effects on gene expression. In Exp 2 we compared PUCs grown on thin and thick layered JMX with added collagen (+C) and to control cells. The JMX layers caused the cells to adopt a small, round shape and to form clumps or colonies during culture. No differences (P > 0.10) were seen between thin10 +C and control wells for viable and total cell counts but thick layered +C resulted in decreased numbers of viable cells compared to thin + C (P < 0.10) and control wells (P < 0.05). In a follow up experiment (Exp. 3) growing the PUCs mixed within, rather than plating on top of, a thick layer of JMX + C caused marked morphological changes with dense 3-dimensional structures formed. Exp 4 compared JMX allowed to gel for 10 (Thin10 +C) or 60 (Thin60 +C) min before the non-gelled fraction was removed. There were no effects on cell numbers at the end of culture (P > 0.10) but Sox2 expression was increased in Thin60 +C compared to controls on plastic (P < 0.05) and Thin10 +C (P < 0.10). In summary, JMX extracts change cell morphology and in some formats increased cell proliferation and may increase Sox2 expression. Further investigation is needed to fully understand the effects of JMX on PUCs.

Doctor of Philosophy / Department of Animal Science / Jim L. Nelssen and Michael D. Tokach / The optimum sampling method swine producers should use to estimate the mean and SD of pig BW within a barn was determined based upon both the time required to conduct and the precision and accuracy of each sampling method. Weighing 5 pigs from 15 pens was determined to be the optimal sampling method. This should require approximately 55 min to complete. Weighing 5 pigs from 15 pens had a CI range of 7.2 to 8.0 kg for estimating the mean BW and 5.6 kg for estimating SD. Next, a meta-analysis was conducted using data from existing literature to generate equations to predict finishing pig back, belly, and jowl fat iodine value. While numerous factors were evaluated, dietary essential fatty acids, dietary net energy content, and backfat thickness had the greatest influence on predicting iodine value of the 3 distinct fat depots. Lastly, 6 experiments were conducted to determine the effects of added Zn on growth performance, pork quality, plasma Zn, and ileal mucosal inflammation mRNA expression of finishing pigs fed diets containing ractopamine-HCl (RAC; Elanco Animal Health, Greenfield, IN). Additional Zn increased plasma Zn and reduced relative expression of IL-1β, but did not improve growth performance of pigs fed diets containing RAC in 5 of the experiments. However, in 1 of the experiments, adding Zn to diets containing RAC resulted in a trend for improved growth performance of pigs. Supplementing the RAC diets with dietary Zn decreased the percentage of type IIA fibers and tended to increase the percentage of type IIX fibers compared to pigs fed the RAC diet without added Zn. Ractopamine-HCl produced chops that were lighter and less red, but possessed reduced metmyoglobin reducing ability at the end of the display period. However, adding Zn to RAC diets increased metmyoglobin reducing ability levels at the end of the display period.

Master of Science / Department of Animal Sciences and Industry / J.S. Drouillard / A series of experiments were conducted in which wheat gluten film forming solutions were modified by various means to produce films that would improve resistance to ruminal degradation. There was an interaction between pH and temperature, whereby low pH (pH 3) and high temperature (75°C) of film forming solution resulted in films that had highest resistance to microbial degradation. Strategies that proved unsuccessful in improving resistance to ruminal degradation included use of the cross-linking enzyme, transglutaminase; induction of a Maillard reaction; and increasing the time of heating film forming solutions. Utilizing HCl versus acetic acid as the means to lower the pH of the film forming solution resulted in poor film formation, which can be attributed to glutenin‟s solubility in acetic acid. When acetic acid was replaced with 25% HCl, however, no compromise in film formation was observed and ruminal degradability was not affected. In order to develop an economical and effective means of encapsulating lysine for rumen bypass, wheat gluten and corn zein were evaluated as encapsulation materials. Coating soybean meal with either wheat gluten or zein resulted in superior protection against ruminal degradation when compared to unprotected soybean meal. Compared to wheat gluten, zein was observed to have greater resistance to ruminal degradation in vitro. Lysine was encapsulated by the spray dry method with wheat gluten or zein. Results from an in vitro ammonia release experiment were inconclusive with respect to effectiveness of the encapsulation process. Wheat gluten films were approximately 59% degraded in pepsin solution. Our results suggest that 72% of the wheat gluten film will bypass the rumen and 59% of the bypass fraction of the film will be degraded in the abomasum. Wheat gluten and zein are suitable candidates for development of encapsulated nutrients for ruminal protection.

Doctor of Philosophy / Department of Animal Sciences and Industry / John A. Unruh / Two experiments were conducted to evaluate the effects of exercise on feedlot cattle well-being, growth performance, and carcass characteristics (Experiments 1 and 2). Additionally, two experiments assessed the volatile compound profiles of beef in response to various postmortem processes (Experiments 3 and 4). Experiment 1 compared heifers (n=30) assigned to either a sedentary treatment or an exercise regimen 3 times/wk (20 min/d for the first 2 wk, 30 min/d for the next 2 wk, and 40 min/d for the final wk). Exercised heifers showed decreased blood insulin, daily gains, final body weights, and lower numerical yield grades in conjunction with decreased a* and b* color values of longissimus muscle lean. Experiment 2 exposed steers (n=419) to 1 of 4 treatments; not exercised (CON), or exercised 3 times/wk by animal handlers for 20-30 min for the first 10 wk (EARLY), the last 7 wk (LATE), or for the entire 116 d finishing period (ALL). EARLY treatment cattle exhibited a decrease in blood insulin while EARLY and ALL treatment cattle produced carcasses with decreased marbling scores in comparison to CON cattle. Experiment 3 assessed the volatile compounds generated by raw and cooked beef gluteus medius steaks (n=30) subjected to blade tenderization and aging times ranging from 5 to 61 d. Raw steaks aged longer than 19 d produced greater concentrations of heptanal, octanal, and nonanal than raw steaks aged 5 d, but cooked steaks showed no change in these compounds in response to aging. Additionally, blade tenderization reduced the concentrations of lipid oxidation and Maillard reaction products in cooked steaks. Experiment 4 investigated cross-sections, external, and internal locations of beef longissimus lumborum steaks (n=54) cooked to 63, 71, or 77 °C and aged for 5, 21, or 37 d. External locations generated aldehydes in greater amounts than internal locations while pyrazines are produced exclusively at external locations. Increases in degree of doneness increased all aldehydes, except nonanal, in steak cross-sections. Aldehydes, except hexanal and octanal, generated from external locations became similar to internal locations as aging times increased. Pyrazines from external locations were reduced by increased aging times.

Doctor of Philosophy / Department of Animal Sciences and Industry / Mike Tokach / In 11 experiments, 7,325 pigs were used to determine the effects of: 1) diet type and form on finishing pig growth performance and carcass fat iodine value (IV); 2) pellet quality and feeder adjustment on pig growth performance; 3) corn particle size and diet form on finishing pig growth performance and carcass characteristics; and 4) dietary acidification, diet complexity, and feed-grade antibiotics on nursery pig growth performance. Feeding diets with wheat middlings and dried distillers grains with solubles all the way until marketing decreased G:F and carcass yield, and worsened carcass fat IV. Withdrawing these ingredients 17 d prior to market restored carcass yield, but resulted in small improvements in IV. Pelleting diets improved growth performance; however, a novel finding is that pelleting diets fed to finishing pigs increased belly fat IV. Feeding nursery pigs from a wide feeder gap may improve ADG and ADFI, with no negative effects on G:F. For finishing pigs, reducing feeder gap reduced feed disappearance and improved G:F. In all experiments, feeding pelleted diets improved G:F, but the greatest improvements occurred when the percentage of fines was minimized. Grinding corn finer than 650 microns decreased ADFI and improved G:F for finishing pigs fed meal diets, but not for pigs fed pelleted diets. Pelleting diets improved ADG and G:F, but the greatest magnitude of G:F improvement to pellets occurred when pigs were fed diets containing the largest particle size corn. Thus, grinding corn finer than 650 microns improved feed efficiency for finishing pigs fed meal diets, but provided no additional benefit for pigs fed pelleted diets. When dietary supplementation of benzoic acid was evaluated, added benzoic acid in nursery pig diets did not influence growth performance in university conditions, whereas feeding complex diets or antimicrobials improved growth. In the commercial setting, acidifiers improved growth in one experiment but not the other. The varying response to acidifiers is likely influenced by health status, age, or starting weight of pigs.

Master of Science / Department of Animal Sciences and Industry / Dale A. Blasi / Drought conditions in the past have created a shortage of prairie hay and other grass hays that are used as roughage sources for receiving and growing beef diets. Historically, wheat straw and other cereal crop residue has been discounted as a feedstuff due to its low nutrient content. Chemical methods, including ammonia application, can improve the feeding value of cereal crop residue while constraining costs. While there are studies that show the efficacy of utilizing ammoniated wheat straw in beef cow and maintenance diets, limited data are available characterizing the feeding value of ammoniated wheat straw in receiving and growing diets. The objective of these two studies were to evaluate cattle growth and diet digestibility for receiving and growing diets containing either wheat straw (STRW), anhydrous ammonia treated wheat straw (AMMN), or a prairie hay and alfalfa blend (CONT) at 30% inclusion. Exp. 1 utilized 288 crossbred steers (271 kg) randomized to 8 pens per treatment and fed their respective test diets for 56 d and a common diet for 14 d to equalize gastrointestinal tract fill. No effect of straw ammoniation was observed on final bodyweight (BW), average daily gain (ADG), dry matter intake (DMI), or gain to feed (G:F) (P > 0.31). The 56-d BW, ADG, and G:F for CONT were significantly different from both STRW and AMMN (P < 0.001). Exp. 2 utilized 6 ruminally fistulated Holstein heifers (288 kg) in a replicated 3 × 3 Latin square design. There were no observed differences between AMMN and STRW in dry matter (DM), organic matter (OM), or ADF intake (P > 0.57) although CONT differed significantly from both straw treatments in DM, OM, and ADF intake (P < 0.05). Digestibility of DM, OM, and ADF were not different between AMMN and STRW (P > 0.43), where as CONT and STRW were different (P < 0.05). Anhydrous ammonia treatment of wheat straw had no effect on ruminal VFA concentration (P > 0.32). Ruminal pH was not affected by anhydrous ammonia application (P = 0.32), but STRW and CONT were different (P < 0.05). Fluid passage rate was not different among the three treatments (P = 0.33). Wheat straw is a suitable replacement for ammoniated wheat straw at 30% inclusion in receiving and growing diets that contain 40% of dietary DM as wet corn gluten feed. Further research is necessary to determine the effect of varying levels of wheat straw and ammoniated wheat straw in conjunction with wet corn gluten feed and other by-product feeds in receiving and growing diets in order to capitalize on performance and efficiency gains while constraining costs.

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.