While equine palatability research has been well documented, the majority of research has been conducted in mature, non-lactating horses (Betz & Lanter, 1980; Van den berg et al., 2016; Goodwin et al., 2005; Francis et al., 2020). While palatability research primarily aims to detect flavor preferences to mask medications, utilize in treats, etc., other aspects focus on acceptance and behavior (Senturklu & Landblom, 2015; Goodwin et al., 2005; Van den berg et al., 2016; Franics et al., 2020). Although a substantial amount of data is conducted on canine olfaction, data pertaining to equine olfaction is quite limited (Francis et al., 2020; Jenkins et al., 2018; Kokocinska-Kusiak et al., 2021). The objective of this study was to investigate the flavor and aroma preferences of lactating equine mare and foal pairings. Stock-type mare and foal pairings (n = 4), aged 6.5 ± 3.9 weeks, were utilized in paired preference testing using apple, anise, peppermint and control palatants. Testing was split into flavor testing (0730-0830 hours) and aroma testing (1630-1730 hours). Mares and foals were loaded into test stalls and allotted 30 minutes to freely interact with treatments. Data was recorded via live stream cameras and evaluated for categorical and numerical data. Variables of interest included: first treatments investigated, consumed, and finished; maternal effects of treatment locations, time spent consuming each treatment, time spent rest recumbent, percentage of treatments consumed, and total voluntary consumption. Data were analyzed using SAS for academics with significance set at 5%. Flavor analysis revealed no preference of first flavor investigated (P = 0.4918), consumed (P = 0.4018) or finished (P = 0.5424) of mares. Foals were also found to exhibit no flavor preferences for first investigated (P = 0.5996), consumed (P = 0.4278), or finished (P = 0.9914). A location effect was exhibited by mares and found that flavor treatments in location 2 and 3 were more likely to be first consumed (P < 0.0001). Foals were more likely to first finish those flavor treatments in location 1 (P = 0.0003). No period effect was exhibited for flavors first investigated (P =0.7552), consumed (P = 0.5404) or finished (P = 0.7903). A period effect was exhibited for first finished flavor treatments of mares (P = 0.0170). Further analysis found that mares were more likely to finish the peppermint flavor for periods 1 and 2 compared to periods 3 and 4 (P = 0.0518). The mean time spent foals spent consuming flavors was not significant (P = 0.2120) and no period effects were exhibited (P = 0.1713). However, time spent resting decreased significantly from period 1 to 4 (P = 0.0476). Likewise, there was no flavor treatment effect on the mean percentage of treatments consumed (P = 0.8431), nor was there a period effect (P = 0.4125). Aroma analysis also found no preference for first investigated (P = 0.8472), consumed (P = 0.8472), or finished (P = 0.8166) of mares. Similarly, foals exhibited no aroma preferences for first investigated (P = 0.5206), consumed (P = 0.5206), or finished (P = 0.1650). A period effect was exhibited for mares for first aroma treatments investigated (P = 0.0101) and consumed (P = 0.01) across periods. However, further analysis found that there was no difference for treatments across periods. A location effect was also exhibited by mares, with location 1 being selected at a lower frequency than locations 2, 3 and 4 (P = 0.0003). Interestingly, locations 3 and 4 had a higher frequency of being the first aromatic treatments finished (P = 0.0008). Foals were found to first consume (P = 0.0315), and finish (P = 0.0013), those treatments located in location 1. Comparative analysis of relationships between mare and foal selective actions found that pairings made similar flavor selections for first investigated treatments (P = 0.1865) but selected different aromatic treatments (P = 0.0415). Likewise, pairings selected similar flavor treatments (P = 0.1062) but selected different aromatic treatments for first consumption (P = 0.0415). Findings suggest that while flavor and aromatic preferences are not strong for mare and foal pairings. However, comparative analysis of selections between the two groups found selections to be similar for flavor testing and different for aromatic testing.

Both centrally and systemically administered dopamine agonists and antagonists decrease ingestive behaviour. The aim of this thesis was to examine whether drugs acting at different receptor subtypes decreased intake in different ways. A microstructural analysis was used to examine dopaminergic drug effects on licking behaviour. A dopamine D3 receptor agonist, 7-OH-DPAT, a dopamine D2 receptor antagonist raclopride and a mixed dopamine D2/D3 agonist quinpirole were compared in this paradigm. These drugs reduced the number of licks by differentially decreasing parameters which are thought to reflect the palatability of the stimulus such as mean bout duration of licking and the initial rate of licking. Follow-up experiments were conducted to further examine the possibility that motor deficits were underlying decreases in licking parameters. The effects of raclopride and 7-OH-DPAT were compared to the effects of a dopamine Dl antagonist SCH- 23390 and were analysed using a brief contact licking test. Again, the behavioural expression of anorexia induced by these drugs seemed to rely on a differential decrease in mean bout duration. Results also revealed that the three drugs used differed in the extent to which they produced a motoric deficit Attempts to block the effects of 7-OH-DPAT on licking (wameters were made by using the putative D3 receptor antagonists PNU-99194A and amisulpride. In addition, the effects of these drugs alone on licking behaviour were examined PNU-99194A failed to block the effects of 7-OH-DPAT and was relatively ineffective in producing changes in licking behaviour when administered alone. Amisulpride blocked the effects of 7-OH-DPAT only at high doses and when injected alone produced an increase in intake through an increase in mean bout duration of licking. Results from Chapters 4,5 and 6 suggested that 7-OH-DPAT was having an effect on palatability. Therefore, Chapter 7 presents an experiment which examines the effect of 7-OH-DPAT on the licking behaviour of rats which encounter a devaluation of reward (successive negative contrast). 7-OH-DPAT reduced successive negative contrast leading to the proposal that D3 receptors may mediate relative as well as absolute reinforcer value. These results bear important implications for understanding the role of dopamine receptor subtypes in components of food reward and appetitive behaviour in general and may well have implications for the treatment of eating disorders.

No description available.

The use of electrolytes in horses has become common in the equine community. Proper management of the equine athlete encourages the supplementation of electrolytes, especially during exercise. Electrolyte imbalance can cause physiological issues including fatigue, irregular heartbeat, cramping, and more. Electrolyte supplementation is utilized to replace losses via the sweat, urine, and defecation. Commercially available oral electrolyte forms include paste, powder, and pellets. Work describing chewable electrolyte use in horses has not been published. The objective of this work is two-fold: to determine preference across four electrolyte chew flavors and to ascertain efficacy of a novel electrolyte product. Protocol approval (#21-029) by Southern Illinois University Institutional Animal Care and Use Committee was obtained prior to initiation of this work. The study was completed in two phases. The first phase examined the palatability of the novel electrolyte chew while the second phase tested the serological effect of the product in exercising horses. In the first phase, stock-type horses (n = 10) were utilized for individual preference testing in palatability stocks over six days. During the palatability session, each horse was permitted 30 seconds to olfactorily investigate the product prior to release for consumption. Immediately following the olfactory period, each horse was allowed up to 5 minutes to voluntarily consume the electrolyte chews. Horses were presented with four treatments (A, B, C, D) on an alternating basis, with two treatments offered side-by-side per day. Treatment formulations consisted of the same base electrolyte content with varying flavors of peppermint, salt, and orchard grass (Table 2). Treatment locations were switched daily to prevent bias associated with location. Variables of interest included number of chews consumed (TI), first action (FA), first choice (FC), time spent consuming (TC) and water consumption (WC) were recorded. Bodyweight (BW) and body condition scores (BCS) were recorded twice over the study duration. Data were analyzed via numerical and categorical methods using PROC GENMOD, PROC FREQ & PROC GLM of SAS (v. 9.5). Significance was set at P < 0.05. There was no significant overall preference for any of the treatment formulations examined. However, there was a significant difference in chew consumption between days 1 and 2 (P = 0.0204). There was also a highly significant treatment effect between days 5 and 6 (P < 0.0001). The relationship between individual horse and consumption was variable and highly significant (P < 0.0001). The mean acceptance rate of the product was 63.6%. These results indicate palatability may differ significantly across horses for the flavors examined. In the second study phase, privately-owned local foxhunting horses (n = 15) were utilized in an exercise study. Due to poor consumption, nine horses were selected for use in the experiment to test treatments. There were three treatment groups: control (CON) offered no supplementation, light (LIG) consumed 6-9 chews, and moderate (MOD) voluntarily consumed 15-20 chews. Baseline jugular venipuncture and vitals assessments were completed on all horses prior to supplementation. Supplementation was offered in two parts: 30 minutes pre-ride and immediately following a 2-hour foxhunt ride in the afternoon. Afternoon temperature was 52°F with mostly sunshine and approximately 42% humidity. Upon return, horses were immediately offered electrolyte supplementation. Venipuncture and vitals assessments were repeated 30 minutes post-ride. Variables recorded were serum values (Na, K, Cl, Ca, HCO−3, Mg), chew consumption (TI), age, respiratory rate (RR), skin turgor (SKN), rectal temperature (BT), distance travelled (DIS) and average speed (SPD). Categorical variables were body condition score (BCS), sex, breed (BRD), and sweat rating (SWR). Data was analyzed via PROC GLM, PROC FREQ and PROC REG dependent on test with SAS (v. 9.5). Significance for all tests was set at P < 0.05. Serological values were unaffected by electrolyte consumption (P > 0.05). Body temperature was significantly higher for all horses following exercise, regardless of treatment group (P = 0.0005). Skin turgor showed significantly more time before return to original state during post-ride evaluation (P = 0.0013). Directional serum changes between Cl and K were significantly correlated (P = 0.0227) as well as Mg and Cl (P = 0.0316). Correlations of relational change between Ca and HCO−3 in addition to Ca and Na were approaching significance (P = 0.0707; P = 0.0800). Mares demonstrated a greater ability to maintain lower post-ride serum calcium levels than geldings (P = 0.013). The effect of breed on serological calcium change may also be considered (P = 0.0312). These results suggest that several major contributive factors require further investigation for the successful implementation of oral electrolyte chews into equine exercise regimens.

Master of Science / Department of Animal Sciences and Industry / Travis G. O'Quinn / The objectives of this study were to determine the effect of enhancement on consumer and trained beef palatability scores of three quality grades when cooked to three degrees of doneness (DOD) and to determine the accuracy and repeatability of the Pressed Juice Percentage (PJP). Striploins of USDA Prime, Low Choice, and Low Select quality grades were used in this study. To maximize variation in juiciness, steaks were either enhanced (formulated for 108% pump with a solution of water, salt, and alkaline phosphates) or non-enhanced, and cooked to three degree of doneness (Rare: 60°C, Medium: 71°C, or Very Well-Done: 82°C). All samples were evaluated for Warner-Bratzler shear force (WBSF), Slice Shear Force (SSF), PJP, and palatability traits by consumer and trained panelists. Consumer panelists rated all enhanced treatments similar (P > 0.05) to each other and greater (P < 0.05) for juiciness, tenderness, flavor liking, and overall liking than all non-enhanced treatments. Consumer ratings of juiciness, tenderness, and overall liking scores increased (P < 0.05) as DOD decreased. Consumer panelists rated all enhanced treatments similar (P > 0.05) and greater (P < 0.05) for the percentage of steaks classified as premium quality. For trained panel initial juiciness, all enhanced treatments and non-enhanced Prime samples were similar (P > 0.05) and greater (P < 0.05) than other treatments cooked to Medium and Very Well Done. Results indicated PJP had a relatively high repeatability coefficient (0.70), indicating that only 30% of the variation observed was due to sample measurement differences. The PJP threshold values evaluated accurately segregated steaks by the probability of a sample being rated “juicy” by consumers, with the actual percentage of “juicy” samples determined to be 41.67%, 72.31%, 89.33%, and 98.08% for the <50%, 50 – 75%, 75 – 90%, and >90% categories, respectively. Therefore, enhancement has a substantial, positive effect on beef palatability. Enhancing higher quality beef does not provide an additional palatability benefit; hence the greatest economic advantage is in enhancing lower quality beef products. Results of this study indicate the PJP juiciness method is both repeatable and accurate at sorting steaks based on the likelihood of a steak being “juicy”.

Master of Science / Department of Animal Sciences and Industry / Travis O’Quinn / The objectives of these studies were to determine how consumer palatability ratings of beef strip loin steaks and ground beef are affected when products are identified with a brand, USDA grade, or product type. Strip loins were selected to represent five quality levels and six ground beef treatments were chosen, representing a variety of fat levels and product types. After aging steaks for 14 d and ground beef for 8 d, 2.5 cm steaks and 151.2 g patties were formed. Consumer panelists evaluated samples for tenderness, juiciness, flavor liking, and overall liking as well as texture liking for ground beef samples. Additionally, consumers rated each palatability trait as either acceptable or unacceptable and rated the sample as either unsatisfactory, everyday quality, better than everyday quality, or premium quality. Samples were fed in two rounds – blind and informed testing. In the first round of blind testing, consumers were served one sample from each treatment with treatments not disclosed. For the second round of informed testing, USDA grade, or product information was disclosed prior to sampling. Samples evaluated by consumers were paired for blind and informed testing. During blind testing, Certified Angus Beef (CAB) steaks rated similar (P > 0.05) to Choice for all palatability traits; however CAB rated greater (P < 0.05) than Choice for all traits for informed testing. Additionally, Angus Select and Select steaks were rated similar (P > 0.05) when tested blind, but Angus Select was rated greater (P < 0.05) than Select for flavor and overall liking when treatment was informed. Prime, CAB, and Angus Select had increased (P < 0.05) ratings for flavor and overall liking due to brand disclosure. However, Choice and Select samples did not receive any increase (P > 0.05) in ratings for palatability traits when brand was informed. Multiple traits were rated greater for Prime, CAB, and Angus Select products indicating these products received a "brand lift" (change in ratings due to brand knowledge) in palatability due to brand identification. However, when brand information was disclosed for Choice and Select steaks, consumers indicated no increase in palatability perception. Few differences were observed in blind testing for ground beef; however, during informed testing, 90/10 CAB ground sirloin rated greater (P < 0.05) than all other products for all palatability traits besides juiciness. Increased (P < 0.05) ratings were found for CAB products for multiple traits while the only non-branded product that received increased (P < 0.05) ratings was 90/10 ground beef during informed testing. There were few differences among ground beef products when tested blind, indicating that during blind testing, brand, fat percentage, and subprimal source have little effect on ground beef palatability. However, when product and brand were identified, multiple treatments received increased ratings for palatability traits indicating branding and product type knowledge influence the palatability of ground beef.

When administered systemically, benzodiazepine receptor agonists have been shown to increase food intake in a number of species. Conversely, benzodiazepine receptor inverse agonists bring about reliable decreases in feeding. The aim of the experiments reported in this thesis was to investigate the brain and behavioural mechanisms involved in the effects of benzodiazepines on ingestion. The effect on food intake of microinjection of the benzodiazepine receptor agonist midazolam into the brainstem of the rat was investigated. A reliable hyperphagic response was elicited following injection of midazolam into both the IVth ventricle and the parabrachial nucleus (PEN). This increase in intake was reversed by pretreatment with the selective benzodiazepine receptor antagonist flumazenil. These results suggest that benzodiazepine receptors located in the brainstem, specifically in the PEN, may be responsible for the effects of benzodiazepines on ingestion. In further experiments, a microstructural approach was adopted which involved analyzing the effects of benzodiazepine ligands on the detailed pattern of licking for both a carbohydrate and a fat in the rat. The effects of midazolam were similar to the effects of increasing concentration. The effects of the benzodiazepine receptor inverse agonist Ro 15-4513 were similar to the effects of decreasing concentration. These results suggest that benzodiazepines influence ingestive behaviour by modulating palatability. The proposal that benzodiazepines may interact with opioids to influence feeding behaviour was examined in Chapters 7 and 8. Although the effects of the opioid agonist morphine and the opioid antagonist naloxone on licking behaviour were not the same as the effects of benzodiazepine ligands, naloxone blocked the effects of midazolam. These results suggest that the effects of benzodiazepine on palatability may depend on release of endogenous opioid peptides. This work has implications for understanding the neural control of ingestive behaviour and may help in developing new therapies for clinical disorders such as anorexia and bulimia.

Doctor of Philosophy / Department of Animal Sciences and Industry / John M. Gonzalez / American beef producers use a multitude of production regimens, with new products constantly becoming available to producers that could ultimately produce beef that fits niche markets. Additionally, U.S. producers employ the use of two exogenous growth promotants (ExGP), anabolic implants and β-adrenergic agonists, to maximize production efficiency. This body of work examined effects of different production strategies on beef quality. In the first study, steers were fed a conventional diet or a diet containing two supplements of the Programmed Nutrition Beef Program (PN) and each diet was fed with or without ExGP. There were no adverse effects on color, but use of ExGP negatively impacted tenderness of steaks. However, the inclusion of the PN supplements decreased purge loss of loins during aging and decreased cook loss of beef steaks. The decrease in purge and cook loss may be intriguing for retailer who purchase-in and cook products as they could specify a demand for beef from animals in this program to potentially save on product losses. Researchers have examined strategies to increase omega-3 fatty acids within beef, as omega-3 fatty acids are health beneficial. The second study examined impacts of feeding increasing levels of a docosahexaenoic acid (DHA)-rich microalgae to heifers on fatty acid profiles, color stability, and palatability of the LM and color and . Feeding increasing levels of microalgae meal quadratically increased total omega-3 PUFA, with increases in DHA content up to 850% and eicosapentaenoic acid (EPA) up to 340% at the greatest feeding level. Although feeding microalgae changed fatty acid profiles to be more health beneficial, color and flavor were adversely affected. At the end of display, steaks from heifers fed the greatest amount of microalgae had reduced a* (redness) values and increases in surface metmyoglobin (discoloration) formation. Panelists detected more off-flavors as the level of microalgae meal increased in the diet. Poor color stability and increases in off-flavors were due to increased oxidation products in these steaks, but problems could be mitigated by inclusion of antioxidants in the diet. The third study presented examined effects of feeding antioxidants to steers fed microalgae meal on color and palatability of Longissimus lumborum steaks. Steers were fed vitamin E at a level over their nutritional need and a selenium-yeast product in addition to feeding microalgae. Again, feeding microalgae without antioxidants in the diet negatively impacted color during display, but feeding antioxidants significantly improved the color stability. There were no off-flavor differences between steaks from steers fed the diet containing only microalgae and diet containing microalgae with antioxidants. Increasing the antioxidant content of the finishing diet when microalgae was fed is feasible way to increase the color stability of steaks and decrease off-flavors of Longissimus lumborum steaks.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第17988号 / 農博第2035号 / 新制||農||1019(附属図書館) / 学位論文||H26||N4813(農学部図書室) / 80832 / 京都大学大学院農学研究科食品生物科学専攻 / (主査)教授 伏木 亨, 教授 保川 清, 教授 安達 修二 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第18695号 / 農博第2092号 / 新制||農||1029(附属図書館) / 学位論文||H27||N4889(農学部図書室) / 31628 / 京都大学大学院農学研究科食品生物科学専攻 / (主査)教授 伏木 亨, 教授 河田 照雄, 教授 安達 修二 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM