WSU College of Veterinary Medicine senior paper highlights

By Haily Saccone (Advisor: Dr. Rusty Stott)

Summary: Johne’s disease, or paratuberculosis, is an infectious and chronic inflammatory disease characterized by small-bowel diarrhea and weight loss in domestic and wild ruminant species. Although Johne’s disease (JD) is primarily a significant disease of cattle, it can also affect other ruminants — including but not limited to: sheep, goats, deer, antelope, elk and bison. JD causes tremendous economic losses every year, with the biggest impact on the dairy industry. The causative agent of JD is Mycobacterium avium subspecies paratuberculosis (MAP), which is an acid-fast bacterium with great affinity for the small intestine of ruminants. MAP is shed intermittently for life in the feces, colostrum and milk of infected animals. The disease caused by MAP is progressive in nature with no efficacious prevention or treatment. Even diagnosis proves a challenge due to the long incubation period of the organism and the inconsistency of shedding from infected animals. Infected animals suffer from decreased milk production, reduced fertility, weight loss, and early cull rates. Despite efforts to control and manage JD, challenges in diagnosis contribute to its persistence in dairy herds.

Conclusions: In conclusion, Johne’s disease, characterized by chronic inflammatory bowel disease in domestic and wild ruminants, poses significant challenges to the dairy industry globally. Mycobacterium avium subspecies paratuberculosis (MAP) is the causative agent, primarily affecting cattle but also other ruminants. The economic losses are substantial, especially in the dairy sector. Despite ongoing research and control efforts, diagnosing and managing JD remains complex due to the prolonged incubation period and intermittent shedding of MAP. The disease’s pathophysiology involves the persistence of MAP in the small intestine, causing a progressive, thickened ileal wall and subsequent granulomatous inflammation. Clinical signs vary through silent infection, subclinical, clinical, and advanced clinical stages. Diagnostic challenges include the lengthy incubation period affecting test sensitivity. Control programs focus on education, management, and herd testing, aiming to reduce MAP transmission and disease prevalence. Treatment options are not curative, with lifelong antimicrobial administration having limited success and practical challenges. Prognosis for infected animals is poor, leading to emaciation and death if not culled. Vaccination against JD proves limited efficacy, and alternative strategies like ionophore antibiotic (monensin) use exhibit varying effectiveness. The potential association of MAP with human diseases, particularly Crohn’s disease, is a subject of debate. MAP has been detected in various sources, including pasteurized milk, baby formula and drinking water, posing potential risks to human health. Ongoing research seeks to clarify the link between MAP and human diseases, emphasizing the need for further investigation and understanding of transmission dynamics

By Brandon Jones (Advisor: Dr. Ramanathan Kasimanickam)

Summary: Since 1956, growth-promoting implants have been a crucial part of the cattle industry, improving daily gain, feed efficiency, and leanness of the carcass. This paper examines their many aspects, including composition, methods of application, physiological effects, regulatory issues, and their function in various stages of production. These implants have set payout ranges and contain either natural or synthetic estrogens, androgens, or progestins. The somatotropic axis is indirectly influenced by estrogenic implants, which results in increased growth. Androgens directly promote the growth of muscle, while lower cortisol levels, which in turn slow down the breakdown of proteins. Growth-promoting substances are regulated by the FDA and go through rigorous evaluations; steroidal implants have been shown to be safe after years of research. Even though implants are least commonly used in nursing calves, it raises average daily gain by 5% with considerations for replacement heifers. Increases from stocker implants can reach 14% for average daily gain, depending on the availability of certain nutrients. A 21% rise is possible with confined feeding, which also increases carcass weight and feed conversion. Important factors to take into account are marketing approach, select-choice spread, and projected days on feed. Hot carcass weights can be maximized with proper implant use during branding, weaning, and feedlot entry, without negatively affecting carcass quality. Overall, an individualized implant strategy offers profitable gains that producers at various production phases can ultimately carry over to cheaper, more available products for consumers.

Conclusions: The use of growth implants in the cattle industry will continue to be a key strategy to meet the escalating demand for protein while navigating challenges posed by limited resources and evolving consumer preferences. From nursing calves to confined feeding scenarios, the nuanced application of these implants reveals a spectrum of benefits and considerations that demand careful evaluation by producers and veterinarians alike. Utilizing implant programs in nursing calves can provide approximately a 5% increase in ADG, but it is important to follow labeled age ranges along with re-implantation rules according to the label. In post weaned calves implants can be a powerful tool to increase gain by 14% and extended release implants can be utilized for longer grazing periods when re-implantation is not an option. Cattle raised in confined feeding environments offer the widest array of options when it comes to approved implants and the possibility of re-implantation. In the finishing phase, crucial considerations include the intended marketing strategy, the choice/select spread, and the anticipated duration of time on feed. By carefully evaluating these factors, producers and animal health professionals can make informed decisions about the most suitable types of implants and the optimal timing for implementing aggressive terminal implants. An effective implant strategy involves taking into account the production phase, goals of the operation, how the cattle will be marketed, genetics of the cattle, and the feed available. Ultimately, there is no one size fits all implant system and using a wealth of published data to build economic models based on documented biological outcomes builds the most effective strategy. Overall, Implants are the most cost- effective technology available to beef producers and are one of the greatest options to optimize resource use and decrease production costs.

By Madison Tripp (Advisor: Dr. John Wenz)

Summary: This paper addresses the growing social media trend of consumers to consume raw milk products. The health risks associated with consumption of raw milk are associated primarily with the presence of microbes in raw milk that are not present in pasteurized milk. There are no nutritional risks associated with raw milk consumption. This review does not include discussion of raw milk contaminants such as antibiotics or mycotoxins. Raw milk serves as a medium for bacterial growth. Campylobacter spp. and Escherichia coli are passed to milk through fecal contamination from the environment. Diseases such as Mycobacterium tuberculosis, Brucellosis, and Q-Fever are caused by bacterial infections in the bovine and can be passed to humans through milk. This paper will discuss these diseases in relation to raw milk consumption. Diseases in humans related to failure of pasteurization or contamination after pasteurization are not discussed.

There are many online presences that promote raw milk and tout its benefits. Advocates argue that raw milk decreases milk allergies, decreases the risk of asthma, is more nutritious than pasteurized milk, decreases lactose intolerance, and is a source of probiotic bacteria. From this review, it is demonstrated that raw milk consumption poses an unnecessary health risk. Raw milk is not safe and carries a significant risk for zoonotic disease transmission to humans. Veterinarians advising raw milk producers should be aware of state specific regulations for testing as well as zoonotic diseases to advise their clients appropriately. Veterinarians are important in advising and implementing biosecurity practices and hygiene protocols to reduce the risk of zoonotic diseases.Conclusions: From this literature review, it is demonstrated that raw milk poses an unnecessary health risk from its possible contamination of pathogenic bacteria. Because of the high nutritional value of milk in addition to its neutral pH and high-water content, raw milk is an excellent growth medium for many microorganisms whose replication depends mainly on temperature. Raw milk consumption is not safe and carries a significant risk for the spread of zoonotic disease. Raw milk advocates claim studies have shown a protective benefit to drinking raw milk and reducing the development of asthma in children, but raw milk has not been proven to be more nutritious or to decrease episodes of lactose intolerance. Veterinarians advising raw milk producers should be aware of the state specific regulations for raw milk sales and potential zoonotic disease risks in order to advise their clients appropriately. Veterinarians are important in advising and implementing biosecurity practices and hygiene protocols to reduce the risk of milk contamination

By Matthew Rafferty (Advisor: Dr. Ramanathan Kasimanickam)

Summary: Selenium is an important trace mineral that is required for many processes within the body including antioxidant defense, enhancing immune function, and proper thyroid function. Selenium deficiency is a problem across the United States and often leads to supplementation to maintain proper dietary support. Improper herd management, mixing errors, or miscalculations of selenium supplements are common reasons for selenium toxicity. Selenium toxicity is characterized as either acute or chronic. Acute selenium toxicity can lead to various clinical signs such as CNS signs, tachycardia, dyspnea, pyrexia, and sudden death, while chronic toxicity may present with more subtle signs, such as alopecia, hoof issues and decreased reproductive rates. Selenium is especially important for reproductive health and embryonic development and play specified roles within the reproductive tracts. This paper explores selenosis clinical signs, effects on reproduction, diagnostics, and treatment.Conclusions: The importance of selenium, especially within our livestock species, cannot be understated. It plays several vital roles throughout the body, and while it is not fully understood, the importance it plays in reproduction is beginning to be. There are many areas within the United States that animals may show disease without proper supplementation. While some of these diseases, such as white muscle disease, present in a very specific way, some signs of chronic deficiency are the same signs that are seen with chronic toxicity. Clinical signs of chronic toxicity such as skin and hair lesions, inappetence, and low reproductive rates should prompt producers to investigate trace minerals in feed, especially that of selenium. Signs of acute selenium toxicity are generally nonspecific, and include CNS signs, tachycardia, dyspnea, abnormal postures, and death. Toxins are generally investigated, and microminerals should be included in this investigation. Important differential diagnoses, such as foot and mouth disease, should be ruled out based on other clinical signs and blood/serum samples.

By Madison Rawls (Advisor: Dr. John Wenz)

Summary: Veterinarians are searching for a way to deliver value in the increasingly competitive ocean of agricultural animal care. The current sector is red and bloody due to increased competition with non-practitioners and producers. The value veterinarians bring, encompassing expertise in animal health and reproduction, faces a shifting landscape as producers take greater control of herd health. Due to this, the value veterinarians provide to producers is diminishing. These trends necessitate changing the current focus for practicing livestock veterinarians. The Blue Ocean Strategy, conceived for business innovation, provides a framework for companies to find and tap into uncontested market space and the unfulfilled wants of consumers. Focusing on those consumers makes these businesses find themselves in a blue ocean free from competition. When applied to the current agricultural animal industry, this strategy offers valuable insights into where veterinarians can discover their blue ocean. The rise of hobby farming and other small but impassioned trends, such as the locavore trend, signifies changing consumer preferences and potential opportunities for veterinarians to add value. The economics of small farms and their demand for veterinary services reveal a blue ocean for veterinarians waiting to be explored. By tapping into this market, veterinarians can add value and generate varied revenue sources within the food-animal sector. Veterinarians must embrace a Blue Ocean approach, innovating their services to align with emerging trends, engage with hobby farmers, and communicate their value in a changing agricultural landscape. Adapting to the demands of alternative agricultural lifestyles will be vital to thriving in this evolving environment.

Conclusions: Hobby farming has become a popular trend among those who want to enjoy the benefits of farming without committing to large-scale commercial operations. As a result, the demand for veterinary care has increased significantly. However, hobby farmers often face challenges in finding veterinarians with species-specific knowledge in their areas and often rely on the internet.
In addition to providing better quality of life and no rural isolation, the role of the agricultural life coach presents an opportunity for veterinarians to expand their client base. By starting their work with preexisting local hobbyists, veterinarians can build their clientele by supporting producers with no previous agricultural experience. The agricultural life coach service can be utilized by any veterinarian, even those with a primary focus on companion animals. Overall, the blue ocean of hobby farming presents a promising opportunity for veterinarians to expand their practice and support the growing trend of sustainable and responsible agriculture.

By Tanya Weber (Advisor: Dr. John Wenz)

Summary: The objective of this retrospective longitudinal study was to assess the association between pregnancies at first service (PFS) and timing of clinical intramammary infection (CIMI) relative to service. Clinical intramammary infection and service records spanning 5 years from 526,230 services on 16 Western U.S. dairy herds were obtained from the HEALTHSUM® database. Services were considered associated with a CIMI event when CIMI occurred 60 days before to 60 days after the service (MBRED). Otherwise, they were considered non CIMI-associated (NoMAST). Service outcome was described based on CIMI timing relative to breeding, lactation group, and herd origin. Data were fitted to a logistic regression model using JASP v. 0.18.3. Service outcome was set as the dependent variable. Grouped days to first CIMI relative to service, lactation group, and herd of origin were set as factors. Differences in service outcome were determined to be unlikely to be the result of random chance when P < 0.05. Of the services analyzed, 41,230 (7.8%) were MBRED. The MBRED group was stratified by timing relative to service based on when the largest change in PFS was observed. A lower PFS was observed when CIMI occurred -7 to +7 days relative to service (PFS = 27.7%) compared to NoMAST (PFS = 42.6%). When CIMI occurred +8 to +60 days relative to breeding, PFS was 37.7%. While this association was substantial (PFS 14.9% lower than NoMAST), the prevalence of MBRED was low (0.8%). Therefore, the impact on PFS over all services was clinically irrelevant, resulting in PFS reduction of 0.02-0.16% when separated by herd. This study demonstrates the importance of considering the clinical significance of important differences in the face of low prevalence of disease.

Conclusions: In conclusion, though a profound association with CIMI and low PFS was identified in this dataset when CIMI occurred near the bred event, the prevalence of CIMI on individual farms was low. This low prevalence translates into a low clinical significance overall on each farm. The information presented in this research emphasizes the importance of considering prevalence of disease when considering overall clinical impact, even in the face of important differences. More research needs to be conducted to assess a more robust economic impact of reduced PFS in association with CIMI. In addition, more research assessing the same parameters as the present study, but looking at subclinical intramammary infection (SCIMI), needs to be conducted, since SCIMI is much more prevalent than CIMI.

By Ashley Wright (Advisor: Dr. John Wenz)

Summary: Utilizing primarily descriptive results from a research survey “small ruminant survey” released in August 2023 and literature review this project attempts to assess the state of veterinary medicine in relation to small ruminant producers. The number of individual small ruminant producers has increased between 2009 and 2019. Small ruminant producers were facing multi-million-dollar losses related to non-predator losses. Common causes of non-predator loss in sheep were old age, parasites, gastrointestinal, lambing problems, and respiratory diseases. Lambs were lost for similar reasons though weather related conditions replaced old age. The survey showed that many small ruminant producers have access to veterinary services. However, several producers reported either not knowing of a veterinarian who would see their species or the closest veterinarian was more than 30 miles away. Small ruminant producers were prone to providing their own veterinary care. Small ruminant producers have had access to over-the counter antibiotics until June of 2023. It was not uncommon for small ruminant producers to provide their own veterinary care and to utilize antibiotics in this process. Overall, a high percentage of respondents understood what the terms withdrawal time, ELDU, and VCPR mean and how to apply them to their livestock. Ultimately the change in available over-the counter-antibiotics that happened in the summer of 2023 will likely have profound effects on the state of small ruminant producers and their use of veterinary services. One way to meet the needs of the small ruminant producer was the use of telehealth. Advancing technology may make this a more feasible option. Ultimately further research into its accuracy, efficacy, and availability needs to be conducted before implementing these as models of medicine.

Conclusions: Further research was needed in this field of veterinary medicine to best meet the needs of our small ruminant producers. This was a valuable industry that was faced with multi-million-dollar losses from potentially preventable causes if access to veterinary care was assessable and utilized. Challenges of availability of veterinarians both in terms of distance and case load can impede the small ruminant’s ability to receive timely medical care for the livestock. When that care was received, they were for the most part satisfied with the care provided, but small ruminant producers have a tendency to provide their own medical care. Some of this ability will now be hampered by the change in OTC antibiotics which will require a valid VCPR. Ultimately veterinarians need to effectively show and communicate the value they can bring to the small ruminant production operation. One way for some of these needs may be able to be met in the future will be to utilize telehealth and remote monitoring technology. However, more research was needed before creating a model of care that more fully integrates these solutions. A possible research study model could be having a group of veterinarians first utilize telehealth such as a video conference interview to assess a sick animal. They would then write down their initial diagnosis, treatment plan, and whether further diagnostics would be warranted. Then having that same veterinarian go and conducts a traditional veterinary appointment. Then compare the accuracy of the telehealth results. Another approach may be to collect a series of case reports with video or images of animals with the details collected during the routine veterinary appointment and care. Then have veterinarians walk through those cases in a telehealth model and see if the resulting diagnosis and treatment were similar.

By Samantha Sweigard (Advisor: Dr. Michela Ciccarelli)

Summary: Farrowing crates were implemented in the mid-late twentieth century to streamline pork production and minimize piglet mortality. While drastic improvements in piglet mortality statistics were seen, public concern over the welfare impacts of farrowing crates on swine has gained much traction in recent decades. Currently, three countries in Europe have banned farrowing crates, and a European Citizen’s Initiative to “End the Cage Age” has been positively accepted by the European Parliament, with promises to phase out and eventually prohibit the use of cages in various animal production systems, including sow farrowing crates, by 2027. The rest of the world has yet to follow suit, though. This paper reviews the physiology of the pig pregnancy, normal maternal behaviors expressed in the pre-, peri-, and post-partum sow, an overview of farrowing crates and their costs and benefits, alternative housing options for the commercial sow, and how sow welfare and piglet survival may be improved in various commercial pork facilities.

Conclusions: It is obvious that farrowing crates have negative impacts on sow welfare, most glaringly so regarding the restriction of movement and utter lack of opportunity to perform natural maternal behaviors in the pre-, peri-, and post-partum sow. While their original purpose was to reduce piglet mortality via crushing, the statistics that may be representative of a global industry are still being argued within the current literature. Farrowing crates pose their own challenges to piglet survivability via an increased stress response during parturition, prolonged farrowing durations, and lack of access to teats, predisposing the piglets to hypothermia, stillbirths, and decreased birth weight and weight gain. Alternative indoor housing options that are being utilized to improve sow welfare throughout the commercial swine industry include modified crates and lactation pens. Additionally, research has shown that providing quality nesting materials to sows in the pre- and peri-partum period has significantly improved sow welfare and piglet survivability. Extrapolating this data and current legislation throughout Europe may aid other countries in taking legal action to improve pig welfare. Modifying farrowing crates through the addition of a hinged door allows for temporary confinement during high-risk periods and increased freedom for the sow, which may be an easier adaptation for some operations. Lactation pens may be modified with protective barriers for the piglets like rails and creep areas. Lastly, the provision of quality nesting material may substantially improve sow welfare via increased peripheral oxytocin concentrations to promote maternal behaviors, reduced stress, and piglet survivability.