By Abby Hayden (Advisor: Dr. Salman Waqas)
Summary: Reproductive performance is a major determinant of a profitable cattle production. Furthermore, artificial insemination has been a major tool for enhancing cattle production and profitability. Estrus detection (ED) and estrus synchronization (ES) are prerequisites for the successful application of artificial insemination programs due to the difficulties in estrus detection using traditional visual observation methods. Several estrus detection and synchronization practices are used in dairy production systems as part of overall reproductive strategy programs. This paper compares different estrus detection and synchronization protocols on various bases, particularly including economic outcomes and reproductive efficiency. The success of a program is measured by calculating various parameters, as well as how well it can be used to meet the goals of a specific production system. Choosing a management practice for a dairy herd or individual cow requires consideration of various factors discussed here, including cyclicity status, climate, herd and animal type, reproductive pathologies, economic status, resource availability, and production goals. This paper comprehensively reviews estrus detection and synchronization protocols with special emphasis on dairy production.
Conclusions: Reproductive efficiency is vital to a profitable dairy production, and the implications of different reproductive strategies have revolutionized the industry by improving pregnancy rates, decreasing calving intervals, and increasing overall production and economic gains. Both estrus detection and estrus synchronization protocols play important roles in achieving these objectives and offer excellent strategies for improving fertility outcomes. If managed well, more traditional estrus detection methods can be cost-effective and take advantage of natural estrous cycles. However, they require consistent labor and monitoring. The consequences of not meeting those standards include missed heats, which can result in extended calving intervals and decreased reproductive performance. They have also been shown to result in lower pregnancy rates.
Estrus synchronization protocols offer a more structured approach that eliminates the need for labor intensive heat detection and allows for fixed time AI. While these programs are usually more costly, they can improve pregnancy rates, reduce days open, and provide a greater control of the breeding schedules. This can be particularly useful in cases where estrus detection is weak or where cows have a higher incidence of metabolic diseases. Timed AI programs are also preferred over estrus detection in cases of cystic ovaries or in the face of heat stress. However, their success depends on the personnel, training, and adherence to the protocols themselves. A combination approach, using both estrus detection methods paired with an estrus synchronization protocol, may be favorable in many situations as well. In herds of mixed parity or variable estrus expression, such as in high-producing cows, using both methods may offer the greatest reproductive success.
Ultimately, the choice to use estrus detection, estrus synchronization, or a combination of both depends on specific factors of each individual herd, and sometimes even to each individual cow, based on factors such as reproductive efficiency, cost-effectiveness, labor availability, and overall management goals. While synchronization protocols often provide a more structured path to achieve higher pregnancy rates, integrating estrus detection may enhance outcomes in specific scenarios. Some herds may benefit most from a combined approach, utilizing the strengths of each method. As reproductive strategies continue to evolve, future research should focus on the implications and applications of these approaches to further increase production and economic profitability.
By Dalton Gibbs (Advisor: Dr. Jennifer Sexton)
Summary: This research paper explores the complexities and challenges of euthanasia in large animal veterinary medicine. With the rise of small hobby farms and companion livestock due to urban expansion into rural areas, veterinarians must address a diverse clientele with varied emotional attachments and expectations about animal euthanasia. The paper discusses the importance of defining euthanasia, but also the veterinarian’s responsibility in ensuring a humane, painless, and stress-free death. Key ethical considerations are examined, highlighting the need for veterinarians to balance animal welfare, client communication, and practical constraints such as skill, safety, and carcass disposal. The American Veterinary Medical Association (AVMA) guidelines and state regulations are reviewed as foundational frameworks for ethical and humane euthanasia. The decision-making process should be collaborative, involving both the veterinarian and the client, accounting for criteria like animal pain, prognosis, individual and welfare, and economic factors. The paper thoroughly reviews primary euthanasia methods in cattle and small ruminants and outlines the mechanisms by which each operates. It explains secondary techniques that are necessary to ensure death when using physical methods. Proper anatomical placement for techniques is detailed, as is the importance of confirming death through observation of multiple criteria. Focus is given to carcass disposal, especially when chemical euthanasia is employed, because certain residues can pose serious environmental and wildlife hazards. Legal, ethical, and practical considerations for disposal methods, including incineration, burial, rendering, and composting, are explained considering regulatory requirements. Overall, the paper stresses that veterinarians practicing large animal medicine must be well-trained in multiple euthanasia protocols, adept at managing sensitive client interactions, and diligent in adhering to ethical and practical standards to ensure humane outcomes for both animals and clients.
Conclusion: Euthanasia in large animal veterinary medicine is a complex, deeply challenging responsibility that requires a nuanced balance of ethical considerations, technical proficiency, and compassionate client communication. As the demographic landscape of livestock ownership continues to diversify, from traditional agricultural producers to small-scale hobbyists and pet owners, veterinarians must be prepared to navigate varied expectations and emotional attachments surrounding the end-of-life decision. This paper highlighted that there is no singular, universally applicable protocol for euthanasia in large animal practice. Instead, veterinarians must rely on a comprehensive understanding of available euthanasia methods, the specific needs of each
animal and client, and an adherence to guidelines established by organizations such as the AVMA. Central to this process is ensuring that the chosen technique is humane, practical, and results in a death that is as painless and stress-free as possible for the animal. Clear, honest, and compassionate communication with clients remains essential throughout the process, from initial consultation to explaining the procedure and its aftermath. Managing expectations and emotions with sensitivity fosters trust and helps clients make informed decisions that align with both animal welfare and their own values. Lastly, the responsibility of appropriate carcass disposal underscores the environmental, public health, and legal implications of euthanasia choices. Veterinarians must remain vigilant about state and federal regulations to protect both wildlife and the broader community. In summary, successful euthanasia in large animal practice requires not only technical skill and regulatory knowledge but also ethical discernment and interpersonal expertise. By embracing these multifaceted responsibilities, veterinarians serve as advocates for both animal welfare and client support, ensuring that the end-of-life experience is conducted with dignity, compassion, and the highest professional standards.
By Anna DeCan (Advisor: Dr. Michela Ciccarelli)
Summary: Oxytocin is a critical hormone in both human and veterinary obstetrics, regulating uterine contractions, facilitating parturition, promoting uterine involution, and enabling milk let-down. Its clinical use spans the management of dystocia, postpartum complications, and lactation support; however, responses vary due to species-specific differences in hormonal priming and oxytocin receptor expression. This paper provides a comparative overview of oxytocin use in dogs, cats, horses, and cattle, highlighting both indications and contraindications. While low-dose, carefully timed administration can be effective in cases of uterine inertia or postpartum uterine clearance, inappropriate use—such as overdosing, repeated boluses, or treatment without ruling out obstruction—can cause severe complications including uterine rupture, fetal hypoxia, or death. Historically, empirical high-dose protocols increased these risks, but evidence-based theriogenology has since guided safer, physiologically informed practices. Today, oxytocin remains indispensable in veterinary reproduction, but its benefits depend on proper diagnosis, judicious dosing, and strict veterinary oversight.
Conclusion: Oxytocin remains one of the most important pharmacologic agents in both veterinary and human obstetrics due to its central role in regulating myometrial contractility, facilitating parturition, promoting postpartum uterine involution, and enabling milk let-down. Across mammalian species, its core mechanism—binding to myometrial oxytocin receptors (OTRs) to increase intracellular calcium and coordinate uterine contractions—is conserved. However, the timing of OTR upregulation, hormonal triggers, and duration of receptor availability vary significantly between species, influencing clinical indications, dosing strategies, and potential risks. In human medicine, oxytocin protocols are well standardized for labor induction, augmentation, and prevention of postpartum hemorrhage. In contrast, veterinary use requires a species-specific approach, reflecting differences in endocrine regulation, receptor dynamics, and labor physiology. While the physiologic foundation—its synergy with prostaglandins, the Ferguson reflex, and lactation stimulation—is shared, these variations demand careful, individualized application in animals. Historically, oxytocin protocols in animals were often based on anecdotal experience rather than evidence-based practice. High-dose administration and frequent repeat dosing were used in attempts to strengthen contractions, sometimes preceding physical examination or veterinary guidance. This practice increased the risk of uterine rupture, fetal distress, and delayed necessary surgical intervention. Advances in theriogenology have since led to physiologically informed protocols that improve efficacy while prioritizing maternal and fetal safety. Today, oxytocin remains a highly valuable tool for veterinarians and, when used appropriately, can be lifesaving for both dam and offspring. However, its safe and effective use hinges on proper diagnosis, veterinary oversight, and client education. Owners and producers must understand that oxytocin is not a benign remedy for any difficult birth, but a potent medication that should only be administered when clearly indicated and under veterinary supervision.
By Michelle Kilpatrick (Advisor: Dr. Jeffrey Olivarez)
Summary: High altitude disease (HAD) is one of the most commonly encountered diseases for ranchers who run cattle at elevations greater than 7,000 feet. The disease is a direct consequence of the low oxygen available in such environments and compounded by the bovine’s increased susceptibility to hypoxia. Because the bovine’s primary response to hypoxia is vasoconstriction, there is a dramatic increase in pressure within the pulmonary vasculature. Overtime, the elevation in pressure will lead to right ventricular hypertrophy and dilation, culminating in right-sided heart failure. As would be expected, clinical signs of HAD are those typically observed with RHF including pitting edema, jugular distension, dyspnea, and exercise intolerance. Most often, diagnosis is made from presence of clinical signs and history of being at high elevation. While treatment measures can be pursued, they are often unsuccessful and unrewarding, making prevention the best option for managing the disease. Prevention is primarily done through testing and selective breeding of those with a low pulmonary arterial pressure. Due to the polygenicity of HAD and pulmonary arterial pressure, single gene selection is not currently feasible. Rather, breeding choice is based on phenotype for those with a low pulmonary arterial pressure (PAP) score. Further, proper herd management such as proper respiratory disease preventative measures and proper pasture rotation and management are also critical for disease prevention. The purpose of this paper is to review the available literature on HAD and present the pertinent information regarding the pathogenesis and pathophysiology with corresponding clinical signs, treatment, testing, and finally management and prevention.
Conclusion: High altitude disease is a historically significant disease of the Mountain West and more recently for low elevation feedyards. In both regions, the disease is a source of significant morbidity and mortality resulting in millions of lost economic opportunity for both production systems. Due to the disease being a consequence of right-sided heart failure, there is no effective way to reverse the associated damage. In turn, this makes treatment an impractical approach, leaving prevention as the most effective modality for management of the disease. This is currently accomplished through pulmonary arterial pressure testing and selective breeding for a phenotype as opposed to genotype. Given the lack of understanding surrounding the genetics of HAD and PAP there is much room for future work surrounding the genomics for this disease.
By Peyton Curtis (Advisor: Dr. Craig McConnel)
Summary: A cowboy is only as good as his calves on the ground. In cow-calf beef operations, calf morbidity and mortality are directly related to the overall efficiency of a producer’s herd. The neonatal period in a calf crop can directly impact the cattlemen’s financial spreadsheets with increased treatment costs, decreased weaning weights and directly affect the annual income by limiting the number of sellable calves in the fall. One of the leading causes of disease and financial hardship within a reproducing beef herd is neonatal calf diarrhea (NCD), and prevention in preweaned beef calves is essential for herd efficiency. It is important to recognize one of the leading causes of morbidity and mortality in beef calves from a veterinary standpoint, but it is also vital to break down these disease processes from a rancher’s standpoint, so they feel adequately equipped to tackle these diseases head on. This paper will discuss the pathogens responsible for neonatal calf diarrhea, as well as management strategies that the producer can implement on their calving grounds. Early recognition and treatment of this neonatal condition is vital in creating a set of high yielding calves to sell in the fall or to improve efficiency in the feed bunk if they are taken to finish. It is essential to equip the cattleman with a toolset to gather diagnoses, administer sufficient and adequate treatment using evidence-based medicine, and initiate accurate preventive measures to set the herd up for success.
Conclusion: Neonatal calf diarrhea (NCD) is a multifactorial disease that can impose significant time and labor demands on producers. While multiple pathogens may cause NCD, effective management primarily involves maintaining a clean environment to reduce pathogen exposure and providing supportive care to guide calves through hypovolemic crises. Additional strategies, such as ensuring adequate colostrum intake and implementing peri-partum vaccination protocols, have demonstrated clear economic benefits for producers. A key takeaway is the practical applicability of these interventions on the farm. Strengthening collaboration between veterinarians and producers is particularly valuable in managing neonatal diseases, optimizing antimicrobial use, and ensuring proper diagnostic submissions. By working together, veterinarians and producers can translate scientific knowledge into on-farm practices, improving calf survival, enhancing productivity, and ultimately increasing profitability.