bluuebunny/crossref_metadata_2025 huggingface dataset:
Reproductive tract infection and inflammation in dairy cows
Authors: LeBlanc Stephen
Published: February 2023

Approximately 30 to 50% of cows are affected by at least one form of reproductive tract disease in the postpartum period. Most cows experience a period of insulin resistance, fat mobilization, inflammation, and reduced effectiveness of immune function in early lactation. The mechanisms which influence the severity of these challenges and consequently the risk of retained placenta, metritis, and endometritis are increasingly understood, but it is not clear how to prevent these diseases through management. Numerous links exist between fat metabolism, inflammation, immune function, and probably feed intake regulation. An excessive pro-inflammatory state early in the postpartum period appears to be a key feature of cows with endometritis about one month later. Aspects of innate immune function are commonly impaired in the transition period, particularly in association with elevated non-esterified fatty acid concentrations · and to a lesser degree by ketosis. Changes in metabolism and immune function precede reproductive tract disease by several weeks. Implementation of nutritional and management best practices are likely to favor metabolic and reproductive health. The effect of purulent vaginal discharge at four to five weeks postpartum on pregnancy rate is mitigated by intrauterine treatment with cephapirin, whereas the effect of treatment with injection(s) of prostaglandin is equivocal. Practical cow-side diagnostic tools for endometritis are needed and effective treatment of endometritis remains unclear.
Difficult conversations with colleagues and staff
Authors: Sterner Keith E.
Published: February 2023

Among the many factors that contribute to the success or frustration of new graduates in a veterinary practice are communications with colleagues and clinical staff. What follows is an attempt to review some of the more common situations that are sure to be encountered and possible strategies for dealing with them. The emphasis here is on the new graduate at entry into practice, with a focus on avoiding the reasons for having difficult discussions in the first place.
Pharmacokinetics and milk elimination of flunixin meglumine in dairy cattle following different routes of administration
Authors: Kissell L. , Smith G. W. , Leavens T. L. , Baynes R. E. , Riviere J. E.
Published: February 2023

Flunixin meglumine (FLU) is a non-steroidal anti-inflammatory licensed for use in dairy cattle for treatment of inflammation in endotoxemia and control of pyrexia associated with bovine respiratory disease and acute bovine mastitis. FLU is labeled for intravenous (IV) administration at a dose of 1 mg/lb (2.2 mg/kg) every 24 hours or 0.5 mg/lb (1.1 mg/kg) every 12 hours. The milk withdrawal time is 36 hours. Currently, FLU is the second most common violative drug residue found in the dairy industry. The reason for the numerous illegal FLU drug residues remains unclear; however, administration by an unapproved route is one possible explanation. The administration of FLU by intramuscular (IM) or subcutaneous (SC) routes may prolong drug elimination and result in milk concentrations of the metabolite, 5-hydroxy flunixin (5OH), the marker residue for milk, to exceed the tolerance level of 2 ppb for > 36 hours. The objective of this study was to determine if the pharmacokinetics and milk residues of FLU and 5OH in lactating dairy cattle differed following IM and SC administration of FLU, compared with those following IV administration of FLU.
Temporal changes in antimicrobial resistance of fecal coliforms isolated from dairy cows
Authors: Corbett E. M. , Norby B. , Halbert L. W.
Published: February 2023

Antimicrobial resistance is a growing concern in both food animal and public health. However, the role of antimicrobial use and management practices used on livestock operations on the accumulation, dissemination, and persistence of resistance has not been clearly determined. Most studies on antimicrobial resistance were conducted as cross-sectional observational studies; therefore, little is known about the dynamics of antimicrobial resistance in an animal as it transitions through various production phases or the impact of antimicrobial treatments on resistance over time. The goals of this study were to determine temporal changes in the quantities of susceptible and resistant coliform bacteria to four antimicrobials in fecal samples that were collected throughout a full production cycle, and to determine whether health or performance events affect the quantity or patterns of antimicrobial-resistant bacteria in dairy cattle.
Use of neurostimulation to localize and anesthetize the brachial plexus of calves undergoing metacarpal surgery
Authors: Lardé H. , Nichols S. , Desrochers A. , Bussières G. , Kopal M.
Published: February 2023

In cattle, locoregional anesthesia is usually effective for surgery distal to the metacarpophalangealjoint. However, for proximal interventions, general anesthesia is often required. The aim of this study was to assess the usefulness of brachial plexus anesthesia for orthopedic surgery in calves. We hypothesized that this locoregional block, combined with sedation, would be sufficient for interventions on the metacarpal bones in calves.
Real-time PCR assay for trichomonosis on pooled direct preputial samples
Authors: Guerra A. Garcia , Hill J. E. , Campbell J. , Waldner C. , Hendrick S.
Published: February 2023

Tritrichomonas foetus is recognized as important cause of reproductive loss in beef herds. Strategies for the control of trichomonosis (trich) in beef herds are based on identifying and eliminating infected bulls. The sensitivity of conventional PCR methods is sufficient for use of detecting trich in pooled preputial samples from up to five bulls. Areal-time PCR (RT-PCR) assay for trich detection has shown improved sensitivity, compared with that of the conventional PCR assay. Previous research from our group demonstrated that pools of samples from up to 25 bulls, enriched by culture, could be tested for trich with the RT-PCR assay without a significant decrease in sensitivity. The objective of the present study was to evaluate the sensitivity of a commercially available RT-PCR assay for the detection of trich in pooled samples of direct preputial samples from five or 10 bulls.
Immune, health, and growth responses of beef calves administered modified-live virus respiratory vaccine in the presence of maternal antibody versus a traditional vaccination regimen
Authors: Powell J. G. , Richeson J. T. , Kegley E. B. , Coffey K. P. , Erf G. F. , Ensley D. T.
Published: February 2023

Typical preconditioning guidelines recommend that calves be vaccinated against respiratory and other pathogens at or near weaning (~205 days) because of the historical belief that maternal antibodies from colostrum ingested by the neonatal calf may interfere with the immune response to vaccination. However, recent research investigating vaccination during the presence of maternal antibodies suggests that neonatal calves vaccinated with a modified-live virus (MLV) vaccine are protected from subsequent BVDV challenge and immature calves vaccinated at 67 days of age develop both an initial and anamnestic antibody response. Our objective was to determine the effects of administration of a pentavalent MLV respiratory vaccine to calves at approximately 60 days of age versus at a traditional vaccination regimen age (near weaning) on health, growth performance, and BVDV type la-specific antibody titers and T cell activation.
survey to evaluate anthelmintic resistance of gastrointestinal stongyles in Iowa cow/calf operations
Authors: Engelken T. J. , Kimber M. J. , Day T. A. , Ubben S. S. , O'Connor A. , Ballweber L. R. , Evans P. K. , Dewell R. D. , Wang C.
Published: February 2023

Parasite resistance, a widespread problem in small ruminants, is starting to appear with increased frequency in beef cattle populations. Reports of parasite resistance in cattle have surfaced in Australia, New Zealand, northern Europe, South America, and the United States. The objectives of this study were to determine whether parasite resistance to commonly used anthelmintics is present in Iowa cow/calf operations, attempt to identify factors that contribute to development of parasite resistance, and utilize qualitative PCR testing to determine which genera of parasites are associated with resistance.
Identification and antimicrobial resistance of Bibersteinia trehalosi
Authors: Dewell G. A. , Thompson C. , Plummer P. J. , Frana T. , Dewell R. D. , Phillips G. J.
Published: February 2023

Bibersteinia trehalosi, (formally Pasteurella trehalosi and Pasteurella haemolytica complex biovar T) is a known cause of disease in ruminants worldwide. Typically, B. trehalosi is associated with pneumonia or septicemia in sheep. Although infection with B. trehalosi is rare in cattle, it is a potential agent responsible for bovine respiratory disease (BRD). Anecdotal reports of increasing prevalence of B. trehalosi in cattle with severe disease have heightened producer and veterinary awareness.

Proper identification of B. trehalosias as a source of an infection is important for making treatment and prevention management decisions. Misidentification of respiratory pathogens is possible without utilization of the proper diagnostic tools. Traditionally, laboratories have relied solely on colony morphology, hemolysis patterns, and sugar fermentation to identify B. trehalosi. The aim of the study was to properly identify B. trehalosi on the basis of phenotypic and biological characterization. Additionally, evaluation of the antimicrobial susceptibility patterns of B. trehalosi from bovine respiratory cases were used to determine the impact of antimicrobial resistance on pathogenicity.
Effect of dietary selenium sources on selenium and glutathione peroxidase concentrations and immune function in beef cattle
Authors: Jinane Noureddine , Chorfi Younes , Couture Yvon , Fournier Alain
Published: February 2023

In dairy cows, several studies have mentioned that selenium (Se) improves immune function mainly through antioxidant enzymes that likely protect immune cells from oxygen-derived radicals. However, in beef cattle few studies have been conducted to evaluate the effect of Se on the immune system. The aims of this study were to determine the effects of source (organic or inorganic) Se supplementation on Se and glutathione peroxidase (GSH-Px) concentrations in beef cows and their calves and on immune variables of the calves.
Estrous response for progestin-based estrous synchronization protocols and subsequent pregnancy rates when using sorted semen in primiparous and multiparous beef cows
Authors: Powell J. G. , Lester T. D. , Davis A. J. , Lindsey B. R. , Shofner R. W. , Rorie R. W.
Published: February 2023

Sorted semen is more costly and often results in lower pregnancy rates than unsorted semen. Therefore, it is important to identify estrous synchronization protocols that maximize expression of estrus and AI pregnancy rates when using sorted semen. Our laboratory has observed good synchrony and AI pregnancy rates for cows synchronized with a 14-day CIDR treatment, followed by GnRH on day 16 and prostaglandin F2 (PG) on day 23. In the absence ofluteal progesterone, a 14-day CIDR treatment should result in the development of a persistent follicle. Thus, our protocol might be improved by the addition of PG on day 7 of the CIDR treatment, to ensure endogenous progesterone concentration is low and that a persistent follicle will develop and respond to GnRH given on day 16. This study evaluated the estrous response and subsequent AI pregnancy rate after synchronization of beef cows with a 14-day CIDR protocol, with an additional PG treatment given on day 7 of the CIDR treatment. A secondary objective was to evaluate the effect of time of insemination after onset of estrus on pregnancy rate when sorted semen was used.
Seasonal variation in milk production and culling in California dairy herds
Authors: Silva-del-Río Noelia , Lago Alfonso , VerBoort Bill , Beaulieu John
Published: February 2023

Heat stress influences production and health in dairy herds. The effectiveness of different cooling strategies could potentially be assessed by the degree of seasonal variability on production and health within a herd. The first step to develop an assessment tool is to understand the regional seasonal variation in production and health. The aim of this study was to evaluate the seasonal variation on milk production, peak milk, and early culling in California Holstein herds.
Pregnancy maintenance in heat stressed dairy cows with gonadotropin-releasing hormone and human chorionic gonadotropin
Authors: Amarloie O. A. , Dini P. , Mottaghian P. , Farhoodimoghaddam M. , Salasel B.
Published: February 2023

Heat stress is one of the main factors associated with low reproductive performance in dairy cows and causes economic losses in high-producing dairy herds throughout the world, especially in tropical areas. Although the exact mechanisms by which heat stress affects fertility is unknown, some theories propose that excessive heat has detrimental effects on follicular development and on progesterone production during the luteal phase of the estrous cycle, which subsequently results in increased rates of early embryonic death (EED). Thus, increasing progesterone concentration could increase fertility in heat stressed dairy herds. One way to achieve an increased progesterone concentration is to support the corpus luteum (CL), the source of progesterone secretion, by means of gonadotropin-releasing hormone (GnRH) or human chorionic gonadotropin (hCG). The objective of this study was to determine whether injection of either two doses of GnRH or a single dose of hCG would increase pregnancy survival in high-producing, heat-stressed dairy cows.
"Moneyball" A new approach to practice
Authors: Schuenemann Gustavo M. , Bas Santiago , Workman Jeffrey D.
Published: February 2023

It is well known that transition cow diseases negatively affect reproductive performance; thus, profitability and welfare of dairy herds. Prevention of diseases at the herd level requires a constant effort and effective coordination of the total system (animals, environment, nutrition, and personnel). Substantial knowledge exists to prevent many diseases or conditions; however, it must be translated into on-farm applications or practices to have a meaningful effect at the herd level. Reproductive data of dairy herds throughout the United States showed that more than 73% of the variation in pregnancy risk (between bottom 10% and top 10% of herds) was due to management practices and/or environment. Fully trained and competent workers know what to do and how to do it, and have the skills and abilities to do the work. However, competent workers will often fail to perform when conflict or lack of satisfaction, motivation, and/or communication occur, resulting in lower work performance which affects the overall herd productivity. Frequent assessment of performance, educational needs, and training of dairy personnel should be top priorities for dairy operations to achieve a consistent and efficient herd performance over time. Practicing veterinarians regularly visit their clients and are ideally placed to identify at-risk dairy herds likely to benefit from personnel training (e.g., calving management), conflict management, and development of preventive standard operating procedures.
Judicious use of antimicrobials in the feedyard
Authors: Sjeklocha David
Published: February 2023

Antimicrobial use in food animals has come under increased scrutiny over the past decade, due to concerns related to antimicrobial resistance. Some reports have indicated that the vast bulk of antimicrobial use occurs in food animals, although many question the accuracy of those reports. Beef cattle producers and veterinarians recognize that antibiotic use is a concern, and have taken steps to educate consumers about antimicrobial use. They have also taken steps to evaluate how they use antimicrobials, and worked to use antimicrobials in an even more judicious manner. Cattle Empire, a large cattle feeding company, has taken a proactive approach to judicious use principles in its animal health program.
BRD in preweaned calves
Authors: Woolums Amelia R.
Published: February 2023

Surveys of cow-calf producers indicate that undifferentiated bovine respiratory disease (BRD) in preweaned beef calves is recognized on approximately 20% of operations. In the US, BRD is reported to be the leading cause of death in preweaning calves 3 weeks of age and older. As compared to feedlot BRD or dairy calf BRD, relatively little information has been published regarding the epidemiology of preweaning beef calf BRD, or risk factors for the problem. However, the available information indicates that the annual incidence of preweaning calf BRD varies significantly between herds, and between years in herds that experience the problem. Calves identified with preweaning BRD have been found to weigh less at weaning than calves not identified with preweaning BRD. While more research is needed, evidence available to date indicates that at the calf level, male calves, calves born with a twin, calves born to a heifer, and calves that experience dystocia requiring major assistance are at increased risk for preweaning BRD. At the herd level, factors that have been associated with pre weaning calf BRD include those that may 1) increase the opportunity for introduction of pathogens new to the herd; 2) increase susceptibility of calves to infection; and/or 3) increase opportunity for close contact among cows and calves within the herd. Because risk factors to date have been identified in cross-sectional surveys and thus are not necessarily causative, more research is needed to confirm the factors that cause preweaning calf BRD, and to identify practices that can mitigate the disease in herds where it is a problem.
Antibiotic treatments for bovine mastitis
Authors: Ruegg Pamela L.
Published: February 2023

Mastitis is the most common disease of dairy cattle, and control of this disease is responsible for the majority of antimicrobials administered to adult dairy cows. Mastitis is detected subsequent to initiation of the immune response based on recognition of inflammation. Thus, most cases present with mild or moderate symptoms, and many cases are culture-negative. Most mastitis is treated by milking technicians without diagnosis of the etiology or review of the medical history of the cow. Obtaining a microbiological diagnosis is essential because some cases may spontaneously cure or respond to short-duration therapy, some cases may require longerduration therapy, some cases are culture-negative, and some cases are caused by pathogens for which there are no effective approved antimicrobials. Practitioners have an opportunity to reduce antimicrobial usage and improve mastitis treatment protocols by targeting treatments based on etiology and cow characteristics. Veterinarians should monitor selected outcomes after treatment and design treatment protocols based on etiological agents specific to individual cases or farms. Milking personnel should be trained to detect abnormal milk and aseptically collect milk samples, but treatment protocols should be performed by animal health managers based on etiology and review of the animal health history. The ability to achieve bacteriological cure is strongly associated with etiology and history of previous cases occurring in the affected cow. The need for antimicrobial therapy and the duration of treatment depend primarily on characteristics of the agent and the ability of the cow to initiate a strong immune response. Bacteria that have the ability to invade secretory tissue, such as Staphylococcus aureus, many environmental streptococci, and many strains of Klebsiella spp typically respond better to extended-duration therapy. In contrast, pathogens that infect superficial mucosal surfaces, such as coagulase-negative staph, Streptococcus agalactiae, and most strains of Escherichia coli) are typically cured with short-duration therapy. Producers should be trained to review the somatic cell count history of the cow and use that data to direct treatment decisions. Cows with a longer duration of subclinical infection prior to the clinical case are more likely to require antimicrobial therapy. The decision to administer antimicrobials should be based on determination of etiology by use of rapid-culture systems used either on-farm or in veterinary clinics. Many mild and moderate clinical cases that are culture-negative and detected in otherwise healthy cows can be successfully managed using a strategy of watchful waiting. Cows that are chronically affected and have frequent recurrences should not be repeatedly dosed with antimicrobials, but should either be culled or have the affected glands therapeutically dried off.
Group-housed feeding systems for dairy calves
Authors: Thomas Mark J. , Capel Michael
Published: February 2023

The practice of group, ad libitum feeding of preweaned calves has recently re-emerged in North America as an alternative to individual housing and management. The interest in these systems has largely been driven by the desire to optimize growth rates through the increased intake of milk or milk replacer, and to reduce labor and management requirements. The benefits of increased rates of gain in milk-fed calves have been well documented through a number of key research trials and meta-analyses. In addition to the apparent health benefits to the young calf, the long-term effect on future milk production has been recognized.

As calf feeding programs have evolved, there has often been the challenge of allowing the calf to consume sufficient milk to meet the needs of accelerated growth. Free access to milk or milk replacer has provided the opportunity to maximize intakes and capitalize on some of the potential benefits of early socialization in a group environment. Additionally, acidification of milk or milk replacer has been shown to have some direct benefits in reducing enteric diseases, and has made it easier to alter traditional management systems.

Some new challenges have also arisen with these feeding and management systems. The ability to provide sufficient ventilation, space, and bedding is a key aspect of minimizing the effect of disease in the group-housed environment. This paper reviews the practical application of group feeding of milk-fed calves, with emphasis on application of ad libitum, acidified milk or milk replacer feeding.
NCIS
Authors: Williamson Lisa H.
Published: February 2023

Haemonchus contortus wreaks havoc on small ruminant and camelid farms in many temperate parts of the world. Unlike many other trichostrongyle nematodes that primarily behave as thieves by robbing animals of body condition, Haemonchus contortus has the distinction of being a killer. This trichostrongyle becomes a "prime suspect" whenever complaints of anemia, weight loss, and death losses arise on farms. As a result, veterinarians need to know how to investigate the scene of the crime, and to help producers recognize and stop management factors that enable criminal behavior in the resident worm population. Control measures need to focus on not only sustaining animal viability, but also preserving anthelmintic efficacy.
Put your money where your mouth is
Authors: Mongini Andrea
Published: February 2023

An effective herd health program fulfills the same goals, regardless of the herd size and species. As a veterinarian, our goal is to educate clients and producers on how to implement a working management program that meets the needs of the animals and owners. Cost and ease of implementation are the 2 factors that are of greatest concern in any herd. While herds vary from small backyard herds to large commercial herds, the goal should be the same-maximize production, efficiency, and profits while minimizing disease, medications given, and involuntary culls. Large herds have different challenges due to less single-animal attention and a need for a total herd approach.
Comparison of the metaphylactic efficacy of gamithromycin, tilmicosin and tulathromycin in beef calves at high risk for BRD
Authors: Miller T. J. , Thomson D. U. , Reinhardt C. D. , Loest C. A. , Hubbert M. E.
Published: February 2023

Bovine Respiratory Disease (BRD) continues to be one of the major health concerns in the cattle industry. It is a multifactorial disease typically caused by infection of immune-compromised calves with both viral and bacterial pathogens. The purpose of this study was to compare the metaphylactic efficacy of various antimicrobials in high-risk beef calves.
Comparison of thoracic ultrasonography with analysis of bronchoalveolar lavage fluid for the diagnosis of subclinical bronchopneumonia in dairy calves
Authors: Ollivett T. L. , Kelton D. F. , Nydam D. V. , Caswell J. , Hewson J. , Duffield T. F. , Leslie Ken
Published: February 2023

The pathophysiology of bronchopneumonia (BP) is such that peripheral airways fill with neutrophilic exudate, which results in pulmonary consolidation and atelectasis. This exudate increases the proportion of neutrophils in bronchoalveolar lavage fluid (BALF), with proportions ranging from 10% to 20% suggestive of BP. Pulmonary ultrasonography (US), which differentiates between aerated and nonaerated lung tissue, has good sensitivity (Se = 85%) and specificity (Sp = 98%) for detection of BP in clinically ill calves and might be useful for diagnosis of subclinical BP. The purpose of this study was to compare thoracic US with BALF as a means to diagnose subclinical BP in dairy calves, with gross postmortem examination used as the gold standard.
Interpretation of repeated testing for Mycobacterium avium subsp paratuberculosis on Ontario dairy herds
Authors: Kelton D. F. , Godkin M. A. , Fairles J. , Roche S. , Van de Water D.
Published: February 2023

The Ontario Johne's Education and Management Assistance Program (OJEMAP) is a dairy industry-funded Johne's disease (JD) control program launched in January 2010. The program offers dairy producers a one-time opportunity to test their adult cow herd for antibodies against Mycobacterium avium subspecies paratuberculosis (MAP) by use of a milk or blood ELISA test. As herds completed their milking herd test, a common question from herd owners and veterinarians was "When should I test next .... how often should I test my herd?" A review of aggressive JD control programs around the world suggests that there are no standard recommendations regarding testing frequency. The Danish program, in existence for 7 years, is based on quarterly testing of the entire milking herd using a milk ELISA. Dr. Soren Nielsen, who developed the Danish Program and serves as its director, argues that given the relatively poor sensitivity of all JD tests, quarterly testing allows each cow to have at least 3 test results per year, the results of which can then be used to classify cows as at high-, moderate-, or low-risk for transmitting MAP to herd mates. Implementation of this strategy has led to a decrease in JD test-positive prevalence from 10% to 6% of cows in herds participating in the program. Unfortunately, this aggressive herd test program carries a high cost and the benefits of quarterly testing over a single annual test are difficult to quantify. The objective of this project was to evaluate and gain experience in the interpretation of repeated testing for MAP with currently available tests in Ontario dairy herds.
Evaluation of monthly individual cow somatic cell count data to predict the risk of exceeding a bulk-tank somatic cell count threshold of 400,000 c/mL
Authors: Fauteux V. , Roy J. -P. , Bouchard Émile , Scholl Daniel , Haine Denis
Published: February 2023

Since August 2012, the upper tolerance limit for bulk-tank somatic cell count (BTSCC) in Canada is 400,000 c/mL. Among Quebec's dairy herds in 2011, 13% of BTSCC analyses exceeded that limit and were at risk of financial penalties. Herd indices on the basis of individual-cow somatic cell count (SCC) variations around a threshold of 200,000 c/mL between 2 consecutive months in lactation have been described (proportion of cows cured, new 'intramammary infection [NIMI], healthy or chronic) and could be used to monitor the dynamics of herd udder health. The objective of this study was to use individual-cow udder health indices for the preceding 3-month period to develop a predictive model to estimate the risk of exceeding the BTSCC limit of 400,000 c/mL the following month.
Impact of uncertainty in foot and mouth disease indirect transmission probability on outbreak duration and number of herds depopulated
Authors: McReynolds S. W. , Sanderson M. W.
Published: February 2023

The central United States (US) has a large livestock population including cattle, swine, sheep, and goats that are susceptible to foot and mouth disease (FMD). Because FMD is a highly infective foreign animal disease, the only method to assess the impact of an introduction and the effectiveness of control programs is via modeling. We developed simulation scenarios to assess the impact of the introduction of FMD in the central US and the effect of vaccination strategies and variation in biosecurity on FMD outbreaks using the North American Animal Disease Spread Model (NAADSM), a spatially explicit, stochastic infectious disease model.
Impact of disease on individual culling risk and herd culling rate in dairy cattle
Authors: Haine D. , Carrier J. , Cue R. , Sewalem A. , Wade K. , Arsenault J. , Bouchard E. , Dubuc J.
Published: February 2023

A culling rate> 30% in dairy cattle is common in United States and Canada, despite general recommendations to lower cull rates in order to save on replacement costs. Also, higher cull rates are sometimes viewed as a sign of management failure, but the association between culling and disease at the cow level may not hold true at the herd level. Therefore, the objective of this study was to explore the relationship between disease events and individual-cow survival, and the relationship between herd-level disease incidence and culling rate.
Role of veterinary practitioners in industry-led dairy health and quality programs in Ontario
Authors: Godkin M. A. , MacNaughton G. , Barratt K. , Church C. , Kelton D.
Published: February 2023

The Ontario dairy industry has recently embarked on a series of health and quality improvement programs for dairy producers as mandated by the national organization, Dairy Farmers of Canada. Uniquely, in Ontario 3 of these programs have been delivered via successful partnerships with private veterinary practitioners. The objective of this research was to illustrate the role private veterinarians can play in industry-led programs, and demonstrate the positive impact of such collaborations.
prevalence of Tritrichomonas foetus in cull cows at a southeastern abattoir
Authors: Jones L. , Palomares R. , Rajeev S. , Ensley D.
Published: February 2023

Trichomoniasis is a sexually transmitted disease in cattle caused by the protozoa, Tritrichomonas foetus. This single-celled, flagellated parasite colonizes the preputial folds of bulls, who serve as asymptomatic carriers of the organism. It is a significant cause of infertility and pregnancy wastage in beef herds. Cows become infected by a carrier bull during breeding, frequently resulting in infertility because of embryonic or early fetal death, abortion, and occasionally pyometra and fetal maceration. Trichomoniasis can be masked by other factors such as poor nutrition, bull subfertility, drought, or other diseases such as leptospirosis and campylobacteriosis. Management practices that perpetuate trichomoniasis include introducing or keeping infected bulls or brood cows in the herd. In some cases, pregnant cows may carry the organism and be a source of infection after calving. Progress in controlling or eradicating trichomoniasis is hampered by the lack of knowledge of its true prevalence throughout the United States. Results of a 2004 report of beef herds in Florida indicated that 11.1% of herds had at least 1 T. foetus-positive bull. Reports documenting the prevalence of T. foetus in beef cows are lacking. Infertility due to infection with T. foetus may be a significant cause of culling in beef cows. However, because of the self-limiting nature of the disease and low sensitivity of culture in cows, testing for T. foetus is not routinely performed on the farm. The objective of this study was to determine the prevalence of T. foetus in the reproductive tracts obtained from cull cows at a Georgia slaughter plant.
Implementation of industry-oriented animal welfare and quality assurance assessment tools in commercial cattle feeding operations
Authors: Barnhardt T. Rooney , Thomson D. U. , Terrell S. P. , Rezac D. J. , Frese D. , Reinhardt C. D.
Published: February 2023

Consumer interest in production agriculture continues to prompt the beef industry to develop tools to increase the accountability of management practices. The purpose of this study was to implement an industry-driven assessment tool, which with the documentation of current practices within the commercial cattle feeding industry, could be used to establish benchmarks for animal health, welfare, and food safety. An assessment tool developed by veterinarians, animal scientists, and production specialists was used to objectively evaluate key areas of beef cattle production including but not limited to animal handling, antimicrobial residue avoidance, cattle comfort, and food safety in feedyards.
Comparison of flunixin pharmacokinetics and milk elimination in healthy cows and cows with mastitis
Authors: Kissell L. W. , Leavens T. L. , Baynes R. E. , Riviere J. E. , Smith G. W.
Published: February 2023

Flunixin meglumine (FLU) is a non-steroidal anti-inflammatory drug that is labeled for use in dairy cattle for regulation of inflammation in endotoxemia and for the control of pyrexia associated with bovine respiratory disease and acute bovine mastitis at a dose of 1.0 mg/lb (2.2 mg/kg), IV every 24 hours or 0.5 mg/lb (1.1 mg/kg), IV, every 12 hours. The milk withdrawal time for FLU is 36 hours. Currently, FLU is the second most common violative drug residue found in the dairy industry. The reason for the numerous illegal FLU drug residues remains unclear; however, prolonged clearance in cows with mastitis, compared with that in healthy cows is one possible explanation. Cows with mastitis may have prolonged elimination of 5-hydroxy flunixin (5OH), the marker residue for FLU in milk, which results in milk FLU residues greater than the tolerance limit of 2 ppb after 36 hours. The objective of this study was to determine if the pharmacokinetics and milk elimination of FLU and 5OH differed between healthy cows and cows with mastitis.
Artificial insemination in beef cow practice
Authors: Van Boening Jeremy
Published: February 2023

Even after a severe drought and a few very challenging years, there is still close to 30 million beef cows in the United States. It is estimated that less than 5% of producers are utilizing an AI program in their herds. Accordingly, there are about 4.1 million replacement heifers in the US with around 15% utilizing AI. The percentage of heifers being bred using AI is on the rise, and will continue to rise as we begin to rebuild the nation’s beef herd. With only 3 to 5% of herds utilizing AI across the United States, there is tremendous room for growth of these services.

We’ve seen the price of bulls go up exponentially over the past few years. The price of an AI program hasn’t changed that much. Semen prices and synchronization drugs have increased by less than 5%. It’s a lot easier to talk to producers about an AI program now than it has ever been in the past. I believe the veterinarian is the person best suited to offer the most complete services. From genetics consultation to synchronization programs to arm service to all the associated services, artificial insemination has the potential to be a profit driver for any bovine-associated veterinary practice.
Quality breeding soundness examination of bulls
Authors: Myers John L.
Published: February 2023

While the attributes of a breeding soundness examination (BSE) are well documented, there is inconsistency among practitioners in the extent, detail, precision, and quality of how this service is provided. There is a constant demand for veterinarians to provide a complete BSE, and producers recognize and appreciate when such an exam is done. By using the electronic breeding soundness exam (eBSE), standardizing examination methods and collecting large amounts of data on the bulls that are tested, the participating veterinarian will realize the advantage of academic and statistical support, professional satisfaction, and an enhanced economic benefit to both the practice and its clients.
Estimation of sensitivity and specificity of a novel clinical scoring system for on-farm diagnosis of bovine respiratory disease in pre-weaned dairy calves
Authors: Love W. J. , Lehenbauer T. W. , Van Eenennaam A. L. , Drake C. M. , Kass P. H. , Farver T. B. , Aly S. S.
Published: February 2023

Bovine respiratory disease (BRD) is an important economic disease of cattle in modern production systems. Control of BRD in calves is especially important because calfhood infections lead to reduced weight gain and productivity. Accurate detection of animals affected with BRD remains a significant hurdle for control and treatment. Several clinical scoring systems for BRD diagnosis have been proposed. One scoring system proposed by researchers at the University of Wisconsin-Madison (WI system, McGuirk, 2008) uses 5 clinical signs, each partitioned into 4 levels of severity. A second system (BRD3 system, Love et al, 2014) was developed at the University of California, Davis, to create a system that required less qualitative categorization of clinical signs and reduced calf handling. The BRD3 system used 6 clinical signs each classified as normal or abnormal. The goal of this study was to estimate and compare the diagnostic accuracy of these 2 clinical scoring systems.
Risk factors in beef cattle for terminal rectal mucosa colonization of Escherichia coli 0157:H7
Authors: Schneider L. G. , Erickson G. E. , Moxley R. A. , Smith D. R.
Published: February 2023

Escherichia coli 0157:H7 (STEC 0157) is an important foodborne pathogen of humans. Cattle are sub-clinically colonized with STEC 0157 at the terminal rectal mucosa (TRM). Live cattle serve as an important reservoir for human exposure, but it is unknown if health or performance characteristics of cattle predict their risk for colonization. Our objective was to test if disease during the finishing phase, growth performance, or carcass quality measurements at harvest increased the odds of E. coli TRM colonization at the time of slaughter.
Evaluation of a handheld device for the detection of β-hydroxybutyrate pre-calving in dairy cattle
Authors: Tatone E. H. , Gordon J. L. , LeBlanc S. J. , Duffield T. F.
Published: February 2023

Individual and herd ketone levels are commonly monitored in dairy cattle post-partum to identify individuals at-risk of metabolic disease and to identify potential improvements to management factors. The Precision Xtra handheld meter has been validated for use for β-hydroxybutyrate (BHBA) measurements post-calving as a convenient cow-side test for ketonemia. Recent research has identified BHBA cut points prepartum associated with increased risk of post-partum disease, but at much lower cut-offs than those indicating hyperketonia after calving: 0.6 to 0.8 mmol/L in comparison to 1.0 to 1.4 mmol/L. The objective of the current research is to validate the handheld device, Precision Xtra, in the measurement of BHBA in whole blood against the gold standard method, laboratory evaluation of serum, to assess its diagnostic accuracy in detecting BHBA pre-calving in the range of 0.6 to 0.8 mmol/L.
Comparison of 4-day vs 5-day controlled internal drug release (CIDR) + timed artificial insemination protocols in dairy heifers
Authors: Palomares Roberto A. , Fishman Heidi J. , Jones Arthur L. , Jenerette Matthew , Vaughn Aimee
Published: February 2023

Previous studies have demonstrated that during the application of a 5-day CIDR + Timed Artificial Insemination (TAI) protocol in dairy heifers, the initial GnRH at CIDR insertion and the second PGF2a 12h after CIDR removal are not essential to optimize pregnancy at TAI (P/TAI; J.Dairy Sci 2011 94:4997- 5004). A major factor limiting the development of these programs in dairy farms is to overlook the importance of applying the hormonal injections at the correct day and time according to the specific protocol. This situation becomes more critical when trying to avoid cattle management practices during weekends. The establishment of a 4-day CIDR+TAI protocol performed on a Monday-Friday schedule would simplify the routine reproductive management of heifers in dairy farms, since it would facilitate treatment administration (Monday: CIDR insertion; Friday: CIDR withdrawal+PGF2a; next Monday: GnRH+TAI). Moreover, in contrast to the 4-day CIDR protocol, both the 5-day and 7-day CIDR programs require handling of animals on three different days of the week. In a recent pilot study heifers treated with a 4-day CIDR+TAI protocol showed an optimal P/TAI (66.7%, 10/15) similar to that observed in the of 5-day CIDR+TAI protocol (46.7%, 7/15) or AI after PGF2a injection and heat detection (46.7%, 7/15). However; despite the numerical differences, in that study the sample size was not sufficient to show statistical differences among groups. The objective of this study was to evaluate the P/TAI in dairy heifers treated with a Monday-Friday 4-day CIDR+TAI protocol compared to that of heifers treated with a 5-day CIDR+TAI protocol.
Use of veterinarians on U.S. dairy operations
Authors: Lombard J. E. , Fossler C. P. , Adams A. E. , Gingrich K. F.
Published: February 2023

For the past 15-20 years, veterinarians have been focused on reproduction management on dairy operations. The introduction of relatively inexpensive pregnancy diagnostic tests could displace the veterinarian from this role on the dairy. There is also a trend for larger dairies to hire non-veterinarians to perform pregnancy exams and surgeries which have been traditionally reserved for veterinarians. Conversely, antimicrobial and other drug use in livestock is coming under increasing scrutiny and veterinarians are likely to have more oversight and responsibility in this area in the future. The objective of this study was to determine the percentage of US dairies that used veterinarians, how frequently veterinarians visited the operation and the services provided by the veterinarian.
Neonatal calf diarrhea
Authors: Miller M. R. , DeWitt S. , Muñoz L. , Habing G. G.
Published: February 2023

Due to concerns about the human health impacts of agricultural antimicrobial use and antimicrobial resistance (AMR), alternatives to conventional antimicrobials are being sought. As a natural component of colostrum, lactoferrin has antimicrobial and anti-LPS capabilities and may have a role for the treatment of calf diarrhea. Diaque™ (Boehringer Ingelheim Vetmedica, Inc., St. Joseph, Missouri) is an oral electrolyte and energy supplement that can be mixed with milk to administer to calves. Diaque may impact the intestinal flora, or may also be a viable option to aid mixture of lactoferrin with milk. This study measured the effects of supplemental lactoferrin and Diaque on concentrations of total and AMR fecal coliforms in two-week-old, Holstein dairy heifers. We hypothesized that supplementation of lactoferrin and/or Diaque would decrease the concentration of total and/or AMR coliforms. Additional objectives of this research included 1) validating a novel technique for measuring AMR coliform concentrations, 2) understanding the dynamics of AMR coliforms early in the calf’s life, and 3) determining the association between passive transfer of IgG on shedding of AMR coliforms.
Effect of milk intake and weaning strategy on measures of calf performance and feed utilization in group-housed Jersey calves
Authors: Michels L. , Godden S. , Ranum J. , Knauer W. , Fetrow J. , Chebel R.
Published: February 2023

Increased milk intake in the preweaning period has been associated with improved rate of gain, improved health, reduced age at first calving and improved first lactation milk production. However, feeding higher levels of milk may slow starter pellet intake, delaying rumen adaptation, which can result in reduced rate of gain and impaired health in the post-weaning period. The study objective was to describe the effect of milk feeding rate and weaning strategy on measures of growth, health, feed intake, feed efficiency and economics in group-housed preweaned Jersey calves.
Injuries and illnesses in performance-age bucking bulls
Authors: Smith J. S. , Angelos J. A. , Chigerwe M.
Published: February 2023

Over the past 2 decades, bull riding has emerged as a growing stand alone industry of domestic and international interest. Currently no studies have evaluated commonly diagnosed injuries and diseases of bucking and rodeo bulls.

The purpose of this study was to describe injuries and disease conditions diagnosed in performace bucking bulls presented to a veterinary medical teaching hospital.
Co-administration of meloxicam and gabapentin does not compromise beef bull semen quality
Authors: Cain A. J. , Comstock J. F. , King E. H. , Hopper R. M.
Published: February 2023

Feet and leg soundness are of critical importance for breeding bulls, and lameness is a common problem affecting bulls. Lameness pain in the bovine typically has both inflammatory and neuropathic components, and often coincides with a decline in fertility. As neuropathic pain is refractory to non-steroidal anti-inflammatory drugs (NSAIDs), y-aminobutyric acid (GABA) analogues are commonly used in conjunction with NSAIDs to treat lameness in cattle. Meloxicam, an NSAID, and gabapentin, a GABA analogue, are frequently used extra-label under the supervision of a veterinarian to mitigate pain associated with lameness. Though neither of these compounds is currently labeled for use in bovines in the United States, previous research has indicated that the pharmokinetic profiles of these drugs support further evaluation for clinical use as analgesics in bovines. A decline in fertility is often observed in lame bulls; however, the pathogenesis of this transient subfertility is unknown. Currently, no controlled studies have been conducted to evaluate the effects of meloxicam and gabapentin analgesics on bull fertility. Thus, the objective of the present study was to evaluate the effects of meloxicam and gabapentin combination therapy on beef bull semen quality. It was hypothesized that treatment with meloxicam and gabapentin might have deleterious effects on semen quality.
Benefits of intrauterine treatment with cephapirin in dairy cows with endometritis
Authors: Tison N. , Bouchard E. , Lefebvre R. C.
Published: February 2023

Reproductive performance of dairy cows (Sheldon et al, 2006) and farm economic efficiency (Bartlett et al, 1986, Drillich et al, 1994, Guard et al, 1994) are related to the health status of the uterus at the end of the voluntary waiting period. Uterine diseases affect about half of dairy cows in the postpartum period (Klucinski et al, 1990, Leblanc et al, 2008) and cause infertility by disrupting uterine and ovarian functions (William et al, 2005).

The hypothesis of the current study was that treatment with antibiotic would improve uterine health and reproductive efficiency in dairy cows with uterine infection. The objective was to assess the efficacy of cephapirin intrauterine treatment preceding a timed Al protocol in lactating cows with purulent vaginal discharge (PVD) and cytological endometritis (CYT).