Beef Science Commons^™

Integration Of Molecular Techniques For The Investigation Of Bovine Respiratory Disease, Amy Abrams

Electronic Theses and Dissertations

Bovine respiratory disease (BRD) is the leading cause of morbidity and mortality in the cattle industry. The complexity of host, pathogen, and environmental factors contributing to the incidence of BRD necessitate a multifaceted approach to investigate BRD. A greater understanding of pathogenic and genetics factors associated with BRD would improve prevention and treatment of BRD. Due to the complexity of BRD, genetic technologies have been limited in their ability to identify a genetic basis for BRD. Pooling of DNA samples prior to extraction can increase the ability to conduct genotyping studies of complex traits. Once generated, new information and management …

Changes In Expression Of The Autophagy-Related Genes Microtubule-Associated Protein 1 Light Chain 3Β And Autophagy Related 7 In Skeletal Muscle Of Fattening Japanese Black Cattle: A Pilot Study, Tomonori Nakanishi, Tadaaki Tokunaga, Takafumi Ishida, Ikuo Kobayashi, Yuta Katahama, Azusa Yano, Laurie Erickson, Satoshi Kawahara

Hebrew Theological College Publications and Research

Objective

Autophagy is a bulk degradation system for intracellular proteins which contributes to skeletal muscle homeostasis, according to previous studies in humans and rodents. However, there is a lack of information on the physiological role of autophagy in the skeletal muscle of meat animals. This study was planned as a pilot study to investigate changes in expression of two major autophagy-related genes, microtubule-associated protein 1 light chain 3β (MAP1LC3B) and autophagy related 7 (ATG7) in fattening beef cattle, and to compare them with skeletal muscle growth.

Methods

Six castrated Japanese Black cattle (initial body weight: 503±20 kg) were enrolled in …

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.

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. …

Effects Of Increasing Dietary Levels Of Carinata Meal On Feeding Behavior, Performance And Carcass Characteristics Of Beef Growing Steers, Alejandro C. Casella

Electronic Theses and Dissertations

The objectives of the present study are to evaluate feeding behavior, animal performance and carcass characteristics of beef growing steers fed increasing amounts of carinata meal (CM). Due to the high protein content of the CM after the oil extraction for biofuel there is an opportunity to use it as a protein supplementation in beef cattle. Twenty-four steers blocked by weight were assigned to four corn-based diets (n = 6 animals per treatment). In the three treatment diets, carinata meal replaced high-moisture corn at 5, 10, or 15%. The diets were fed using the Insentec RIC system for 138 days. …

Investigation Of Bovine Conceptus Galectins And The Effect Of Bovine Conceptus Secretory Proteins On The Endometrial Epithelial Transcriptome, Heather Lynn Baldwin

Graduate Theses, Dissertations, and Problem Reports (ETD)

Pregnancy loss in cattle is greatest in the first 30 days of gestation. Near d15 of gestation, bovine conceptuses elongate and express LGALS1, an immunosuppressive glycan-binding protein believed to be essential for implantation. However, other members of the bovine galectin family, including LGALS3, LGALS4, LGALS7, LGALS8, LGALS9 and a galectin-13-like gene (LGALS13L), also may be expressed by the elongating conceptus. Therefore, galectin expression in elongating, d16 bovine conceptuses and intercaruncular endometrium as well as elongating, d14 ovine conceptuses and intercaruncular endometrium was assessed by RT-qPCR. Angus heifer and Texel ewes underwent estrous cycle synchronization and either inseminated or not bred. …

The Effect Of Bovine Galectin-1, A Conceptus Secretory Protein, On The Endometrial Transcriptome, Lindsay Faye Grose

Graduate Theses, Dissertations, and Problem Reports (ETD)

Early embryonic loss in cattle is detrimental to reproduction thus, the profitability of both the beef and dairy industries. Therefore, an important aspect of study is to find techniques that beef or dairy producers could use to decrease early embryonic loss Galectin-1, the protein that was investigated in this research is important in modulating the maternal immune system in rodent and human early pregnancies by promoting fetomaternal immune tolerance. The role of galectin-1 within the reproductive tissues has not been thoroughly investigated in cattle. Galectin-1 is located in the caruncular and intercaruncular regions of the bovine endometrium, specifically the maternal …