Animal Sciences Commons^™

Responses Of Bovine Pituitary Transcriptome Profiles To Consumption Of Toxic Tall Fescue And Forms Of Selenium In Vitamin-Mineral Mixes, Qing Li

Theses and Dissertations--Animal and Food Sciences

The first goal of the current research was to determine whether gene expression profiles differed between whole pituitaries of growing beef steers grazing pastures containing high (HE) or low (LE) amounts of toxic endophyte-infected tall fescue. The global (microarray analysis) and selected targeted (RT-PCR) mRNA expression patterns of pituitaries collected from beef steers (BW = 266 ± 15.5 kg) that had been randomly assigned to undergo summer-long grazing (89 to 105 d) of either HE (0.52 ppm ergot alkaloids) or LE (< 0.03 ppm ergot alkaloids) pastures were compared. Gene expression data were subjected to one-way ANOVA. The pituitaries of HE steers had 542 differentially expressed genes, and the pattern of altered gene expression was dependent on treatment. Targeted RT-PCR analysis corroborated these findings, including decreased expression of DRD2, PRL, POU1F1, GAL, and VIP and that of POMC and PCSK1, respectively. Canonical pathway analysis (Integrated Pathway Analysis, IPA) identified HE-dependent alteration in signaling of additional pituitary-derived hormones, including growth hormone and GnRH. In conclusion, consumption of endophyte-infected tall fescue alters the pituitary transcriptome profiles of steers in a manner consistent with their negatively affected physiological parameters. The second goal of this project was to test the hypothesis that sodium selenite (ISe), SEL-PLEX (OSe), vs. a 1:1 blend (MIX) of ISe and OSe in a basal vitamin-mineral (VM) mix would differentially alter pituitary transcriptome profiles in growing beef steers (BW = 183 ± 34 kg) commonly grazing an endophyte-infected tall fescue (HE) pasture. Steers were randomly selected from herds of fall-calving cows grazing HE pasture and consuming VM mixes that contained 35 ppm Se as either ISe, OSe, or MIX forms. Steers were weaned, depleted of Se for 98 d, and subjected to summer-long common grazing of a 10.1 ha HE pasture containing 0.51 ppm ergot alkaloids. Steers were assigned (n = 8) to the same Se-form treatments on which they were raised. Selenium treatments were administered by daily top-dressing 85 g of VM mix onto 0.23 kg soyhulls, using in-pasture Calan gates. Pituitaries were collected at slaughter and changes in global (microarray) and selected (RT-PCR) mRNA expression patterns determined. The effects of Se treatment on relative gene expression were subjected to one-way ANOVA. The form of Se affected the expression of 542 annotated genes. Integrated Pathway Analysis found a canonical pathway network between prolactin and POMC/ACTH/ α-MSH synthesis-related proteins, and that mitochondrial dysfunction was a top-affected canonical pathway. Targeted RT-PCR analysis found that the relative abundance of mRNA encoding prolactin and POMC/ACTH/ α-MSH synthesis-related proteins was affected by the form of Se, as were mitochondrial dysfunction-related proteins OSe steers appeared to have a greater prolactin synthesis capacity vs. ISe steers through decreased dopamine receptor D2 signaling, whereas MIX steers had a greater prolactin synthesis capacity and release potential by increasing TRH concentrations than ISe steers. OSe steers also had a greater ACTH and α-MSH synthesis potential than ISe steers. We conclude that form of Se in VM mixes affected genes responsible for prolactin and POMC/ACTH/α-MSH synthesis, and mitochondrial function in pituitaries of growing beef steers commonly grazing an HE pasture. The third goal was to test the hypothesis that sodium selenite (ISe), SEL-PLEX (OSe), vs. a 1:1 blend (MIX) of ISe and OSe in a basal vitamin-mineral (VM) mix would differentially alter selenoprotein profiles in pituitaries and livers of growing beef steers commonly grazing an endophyte-infected tall fescue (HE) pasture (i.e., the same steers used in Goal 2). The effects of Se treatment on relative gene expression were subjected to one-way ANOVA. The mRNA content of 6 selenoproteins in the pituitary was affected by Se treatments, along with two selenoprotein P receptors, whereas the expression of two selenoproteins was altered in the liver. We conclude that the change in selenoprotein gene expression in pituitaries indicates that OSe steers have a greater potential capacity to manage against oxidative damage, maintain cellular redox balance, and have a better quality control of protein-folding in their pituitaries than ISe steers. The change in selenoprotein gene expression by the liver indicates that MIX steers have a greater redox signaling capacity and capacity to manage oxidative damage than ISe steers.

Effects Of Yeast-Derived Microbial Protein On Transition Dairy Cow Health And Performance, Gustavo Mazon Correa Alves

Theses and Dissertations--Animal and Food Sciences

The transition period for dairy cows is defined as the three weeks pre and postpartum. During the transition period, dairy cows experience a myriad of metabolic, managerial, and nutritional requirement changes. These changes lead to stress and increased susceptibility to diseases which can negatively affect lactational performance in the short and long term. However, dietary amino acid availability can have a dramatic impact on the health and performance of dairy cows around parturition. Thus, the objective of the thesis was to evaluate the effects of supplementing yeast-derived microbial protein, as an alternative protein source for dairy cows during the transition …

The Evaluation Of Pathogen Survival In Dry Cured Charcuterie Style Sausages, Jennifer Michelle Mcneil

Theses and Dissertations--Animal and Food Sciences

The objective of this study was to evaluate the survival of non-O157:H7 STEC, Salmonella spp., and S. aureus in dry fermented sausages. Chorizo and Landjager sausages were inoculated with individual bacterial cocktails and stuffed into natural casings. Temperature, relative humidity, pH, and water activity were monitored through fermentation, drying, and storage. Bacterial counts were determined by serial dilution and plated in triplicates on selective media. Plates were incubated at 37°C for 24 hours and colony forming units per gram (CFU/g) were observed.

Results of the first study validate that contaminated raw materials contribute to pathogen survival and background bacteria outcompeted …

Long-Term Effects Of Different Fat Sources And Vitamin E Supplementation On Growth Performance, Antioxidant Status, Carcass Characteristics, Meat Quality, And Immune Capacity Of Pigs With Heavy Slaughter Weight Up To 150 Kg, Ding Wang

Theses and Dissertations--Animal and Food Sciences

Two experiments were used to evaluate the potential interaction of fat source and vitamin E (VE) in heavy slaughter weight pigs. In Experiment 1, a total of 64 individually-fed pigs (28.41 ± 0.83 kg) were randomly assigned to 8 dietary treatments in a 4×2 factorial arrangement. Fat treatments included cornstarch (CS), tallow (TW), corn-oil (CO), and coconut-oil (CN). VE treatments were dietary α-tocopheryl acetate (ATA) at 11 and 200 ppm. In Experiment 2, a total of 72 individually fed pigs (28.55 ± 1.16 kg) were randomly assigned to 12 dietary treatments in a 2 × 6 factorial arrangement. Fat treatments …

An Appraisal Of The Effect Of Nursing Location On Weaning Weight Of Piglets And Its Dependence On The Feeding Of Essential Oils To Sows, Shannon L. Dierking

Theses and Dissertations--Animal and Food Sciences

The objective of these studies was to evaluate the effect of piglet nursing location on weaning weight, and its dependence on essential oil supplementation on sow and piglet performances.

Piglets that nursed anterior teat pairs had heavier weaning weights and higher gain for the lactation period. Additionally, piglet birthweight did not impact their overall teat selection and nursing location. These results provide some insight into the biological aspects of sow milk production, and implied that milk yield may vary between teat pairs along the udder line.

Supplementation of essential oils (EO) during late gestation and lactation had no effect on …

Automated Body Condition Scoring: Progression Across Lactation And Its Association With Disease And Reproduction In Dairy Cattle, Carissa Marie Truman

Theses and Dissertations--Animal and Food Sciences

Body condition scoring is a technique used to noninvasively assess fat reserves. It provides an objective estimate to describe the current and past nutritional status of the dairy cow and has been associated with increased disease risk and breeding success. Traditionally body condition scores are taken manually by visual appraisal on a 1 to 5 scale, in one-quarter increments. However, recent studies have shown the potential of automating the body condition scoring of cows using images. The first objective was to estimate the likelihood of disease development and breeding success, using odds ratios, associated with body condition score scored automatically …

Forms Of Supplemental Selenium In Vitamin-Mineral Mixes Differentially Affect Serological And Hepatic Parameters Of Growing Beef Steers Grazing Endophyte-Infected Tall Fescue, Yang Jia

Theses and Dissertations--Animal and Food Sciences

Consumption of endophyte-infected tall fescue results in a syndrome of negatively altered physiological systems, collectively known as fescue toxicosis. Another challenge to endophyte-infected tall fescue -based beef cattle operations is that the soils often are selenium (Se) poor, necessitating the need to provide supplemental Se. To test the general hypothesis that different forms of supplemental Se would ameliorate the negative effects of fescue toxicosis, predominately-Angus steers (BW = 183 ± 34 kg) were randomly selected from herds of fall-calving cows grazing an endophyte-infected tall fescue pasture and consuming vitamin-mineral mixes that contained 35 ppm Se as sodium selenite (ISe), SELPLEX …

Relationships Between Animal Temperament And Systemic Immune Responses In Beef Cattle Exposed To Conditions Associated With Conventional Management, Alexander W. Altman

Theses and Dissertations--Animal and Food Sciences

Measures of temperament have been shown to influence physiological responses. Exit velocity (EV) has been identified as an objective, robust measure of temperament that can be used to predict subsequent performance of cattle. Additionally, previous studies from our lab indicate this measure of temperament may be related to production of interferon-γ (IFN-γ), a cytokine associated with cell-mediated immunity (CMI). Whereas research has investigated effects of EV upon immune responses, the overall goal of these studies was to examine this relationship under a variety of scenarios including human handling, transportation, and exposure to endophyte-infected tall fescue (E+) for determination of its …

Validation Of An Automated Behavior Monitoring Collar, And Evaluation Of Heat Stress On Lactating Dairy Cow Behavior With Access To A Free Choice Soaker, Lori Nicole Grinter

Theses and Dissertations--Animal and Food Sciences

Precision dairy technologies (PDT) are becoming more accessible and are therefore becoming more common on commercial dairy farms and in dairy research. Prior to any use of PDT, one should understand the precision, accuracy and bias of the device by a validations studies before interpreting the behavior measurements. Thus, the objective of the first section of my thesis is to validate ruminating, feeding and resting measurements of a behavior monitoring collar used in the second section. Precision dairy technology is used in heat stress studies to compare behavior of cows exposed to different heat stress treatments or abatement strategies. Heat …

Evaluation Of Current And Emerging Techniques For Measuring Eggshell Integrity Of The Domestic Fowl, Lauren Wood Nolan

Theses and Dissertations--Animal and Food Sciences

This dissertation is an investigation into the effect of different zinc sources and levels on eggshell quality and microstructure, as well as keel bone damage. Eggshell function is two-fold; eggshells function to protect the developing embryo, as well as act as a barrier against bacterial penetration, optimizing food safety of the egg for human consumption (Mabe et. Al., 2003). Two small trials were conducted in order to determine differences in eggshell microstructure of eggs produced from hens at peak lay (26 weeks of age) and at the end of lay (88 weeks of age). Two groups of hens were fed …

Improved Iron Status In Weanling Pigs Leads To Improved Growth Performance In The Subsequent Nursery Period, Tyler Chevalier

Theses and Dissertations--Animal and Food Sciences

The objectives of this thesis were: 1) to assess the iron status of piglets, 2) to thoroughly evaluate the blood profile, growth performance, and tissue mineral concentration of young pigs during the pre and postweaning periods after receiving various dosages of iron (0, 50, 100, 200, and 300 mg iron) at birth, 3) as well as evaluate the effects of an additional iron injection before weaning on hematological measures, growth performance, and tissue mineral concentration postweaning. In the initial experiment, there was a 60% incidence of iron deficiency at weaning after administration of a 150 mg iron injection at birth. …

Metabolizable Energy Determination In Broiler Chickens, Andrew E. Dunaway

Theses and Dissertations--Animal and Food Sciences

Feed accounts for the highest cost associated in poultry production, with energy-containing feedstuffs being the most expensive portion of the cost of feeding. The increasing demand for poultry meat gives reason to determine accurate apparent metabolizable energy (AME) values for various feedstuff through measuring energy utilization in the birds. The adaptation length of birds fed an experimental diet may affect the determined AME value due to the diet matrix and physiochemical properties of the feedstuff. Therefore, the objective of this thesis was to evaluate a select group of energy-containing feedstuff with different diets and with factors such as coccidia challenge …

Anthelmintic Resistance In Equine Parasites: Mechanisms And Treatment Approaches, Jessica Scare Kenealy

Theses and Dissertations--Veterinary Science

Anthelmintic resistance of parasites infecting livestock animals is a global problem resulting in decreased animal welfare and production losses. Horses are not exempt from this issue as wide-spread anthelmintic resistance exists among the equine cyathostomins and Parascaris spp. Of the three drug classes available for treating equine intestinal helminths anthelmintic resistance, defined as less than 90-95% drug efficacy, exist to all three. New pharmaceutical control regimens and the elucidation of parasite drug response mechanisms are needed.

Two studies were carried out evaluating combination deworming regimens. A population of cyathostomins with known resistance to the benzimidazole (BZ) and pyrimidine drug classes …

Effects Of A Systemic High Urea Concentration On The Endometrial And Embryonic Transcriptomes Of The Mare, Yatta Linhares Boakari

Theses and Dissertations--Veterinary Science

Pregnancy loss remains a major source of economic cost to the equine industry. Frequently, the exact causes of pregnancy loss remain unknown. It has been shown, in other species, that increased dietary protein leading to elevated blood urea nitrogen concentrations (BUN) can be a factor in decreased survival of the early embryo. Our studies provided novel information regarding the effects of elevated BUN on endometrium and embryos from mares as well as insights on changes in their gene expression. Our first objective was to develop an experimental model to elevate BUN during diestrus using intravenous urea infusion. We analyzed the …

Quantifying White-Tailed Deer Density And Its Impacts On Agricultural Systems, Jonathan A. Matthews

Theses and Dissertations--Forestry and Natural Resources

White-tailed deer (Odocoileus virginianus) commonly consume row crops, with yield losses often attributed to their browsing. Deer density and field morphology may predict yield losses within local areas. We sought to 1) determine the effects of deer browsing on corn and soybean yields and investigate if deer density or field morphology correlated to yield loss in western Kentucky, and 2) compare pellet-based distance sampling to game camera surveys to determine if a distance sampling technique could accurately estimate deer density during the growing season. Overall, deer reduced corn and soybean yields on one-half of surveyed properties. Deer density …

Evaluating Costs Associated With Management Decisions Of Replacement Dairy Heifers And Their Impact On The Total Rearing Investment, Anna Catherine Hawkins

Theses and Dissertations--Animal and Food Sciences

Replacement heifer rearing is critical for the future of the dairy operation, especially to improve genetic merit and maintain herd size. A replacement heifer from the day she is born to the day she calves herself is generally a 2-year investment without potential income. A myriad of options exists on how to manage, fed, and ultimately raise replacement heifers. This study quantifies the costs associated with replacement heifer management decisions from birth to calving related to housing, labor, feed and health. The heifer rearing period can be broken into pre and post weaning sections to allow for more understanding the …

Developmental Changes In The Pig From Birth To 42 Days Post-Weaning (1.5 – 25 Kilograms Bodyweight), Sarah K. Elefson

Theses and Dissertations--Animal and Food Sciences

This study evaluated the changes in body composition, glycogen tissue reserves, visceral organ growth, and small intestine morphology in the young pig. A total of 96 crossbred pigs were euthanized at birth (pre-suckle), days 1, 2, 3, 5, 7, 14 postpartum, weaning at day 21, and days 1, 2, 3, 5, 7, 14, 28, and 42 post-weaning. Body composition of the pig had increasing dry matter and fat, decreasing ash, calcium and phosphorus, and relatively static protein percentage over the course of the study. Liver and muscle glycogen was greatest at birth. Following birth and weaning there was a distinct …

Behavioral And Physiological Adaptations Associated With Feed Intake During Transitioning Cattle To High-Grain Diets, Amanda M. Mclean

Theses and Dissertations--Animal and Food Sciences

Transitioning cattle from a high-forage to a high-concentrate diet increases the risk for ruminal acidosis and is often related to decreased feed intake, which compromises animal health and performance. Since control of feed intake and rumen motility are closely related, we hypothesized that a reduction in rumen motility may be associated with a reduction in feed intake during this transition. Computer programs were created to analyze feed disappearance and rumen pressure data for feeding behavior as well as identification and characterization of rumen contractions, respectively. This method enabled timely analysis of large datasets and removed subjectivity associated with manual analysis. …

Microalgae And Zinc Source Supplementation Of Broiler Breeder Diets Affects Broiler Breeder Skeletal Development And Reproduction With Transgenerational Impacts On Offspring Performance And Skeletal Characteristics, Marquisha A. Paul

Theses and Dissertations--Animal and Food Sciences

Leg problems and disorders are of major concern for the poultry industry and animal welfare. Previous studies suggest that it may be possible to improve skeletal characteristics through nutrition. Omega-3 fatty acids, including Docosahexaenoic acid (DHA), are essential nutrients and are known to play an important role in bone tissue development. FORPLUS™ (Alltech, Inc.) is an unextracted, whole-cell microalgae (Aurantiochytrium limacinum CCAP 4087/2) that contains 64% fat and 16% DHA. Zinc (Zn) is a trace element and essential nutrient for growth and skeletal development. Bioplex^® Zn (Alltech, Inc.) is a Zn proteinate that has been shown to be …