bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of a Milk Strip Test for Detection of Subclinical Ketosis at Cow Level
Authors: Bélanger Anne-Marie , DesCôteaux Luc , Couture Yvon , Baril Jean , Bagg Randal
Published: February 2023

Subclinical ketosis is a metabolic disease that has been associated with reduced milk production, and impaired fertility. Duffield et al (2001) have reported a median prevalence of subclinical ketosis of 41% among 25 Ontario Holstein herds, and a within-herd prevalence ranging between 8 and 80%. Our study was designed to evaluate the use of a milk strip test as a cow-side test for detection of subclinical ketosis, and to discuss its potential practical application to a herd health-monitoring program.
Prognosis for Survival after an Open Abomasal Surgery Following an Unsuccessful Toggle-Pin Fixation in Dairy Cows
Authors: Perkins G. A. , Nydam D. V. , Kimball S. A. , Fubini S. L.
Published: February 2023

Displaced abomasums are among the most common production-limiting conditions needing veterinary medical and surgical attention. Randomized clinical trials have shown an equally good prognosis for open surgical correction and toggle-pin fixation. Both procedures have advantages and disadvantages, complications and failures. There has been a perception that cows that have had toggle-pin fixation with bad outcomes may not be salvageable. The purpose of this study was to investigate the outcome of surgical correction following a failed roll-and-toggle procedure, and to identify prognostic indicators.
Effects of Sprinkler, Shade and Fan Cooling of Preparturient Holstein cows on Post-parturient Milk Performance during Summer Heat Stress
Authors: Urdaz J. , Overton M. , Moore D. , Santos J. E.
Published: February 2023

Heat stress has important consequences for animal welfare and production performance, and has been implicated as the most important reason for decreased milk production during summer time. Due to lower milk production, most research has targeted prevention of heat stress in lactating cows. Few investigations, however, have focused on cooling preparturient dairy cows during the non-lactating period, and no research has reported the effects of cooling during the last three weeks of gestation. The purpose of this study was to examine the effects of shades, fans, and sprinklers on the last three weeks of gestation of Holstein cows during summer heat stress. Outcome variables included post-parturient milk production, rectal temperature, body condition score (BCS) and incidence of post-parturient disorders.
Validation of a Monoclonal Antibody Capture ELISA to Detect Antibodies to Leptospira borgpetersenii serovar hardjo
Authors: Kavanagh O. V. , Skibinska A. , Mackie D. P. , Montgomery J. M. , Logan E. F. , Ellis W. A.
Published: February 2023

In this paper we will outline the validation of this ELISA and demonstrate its potential importance in the control of bovine leptospirosis.
Effectiveness of an Internal Teat Seal in the Prevention of New Intramammary Infections During the Dry and Early Lactation Periods in Dairy Cows When Used with an Intramammary Antibiotic
Authors: Godden S. , Rapnicki P. , Stewart S. , Fetrow J. , Johnson A. , Bey R. , Farnsworth R.
Published: February 2023

The practice of blanket dry cow antibiotic therapy has been very successful in eliminating many existing infections at dry-off and in preventing new intramammary infections (IMI) during the dry period. However, many new intramammary infections still occur during the dry period due to factors such as delays in keratin plug formation, poor sensitivity of some invading pathogens to intramammary antibiotic preparations, and decreases in antibiotic concentrations near the end of the dry period. The primary objective of this study was to describe whether quarters treated with an internal teat sealant in addition to an antibiotic (treated) at dry-off would develop fewer new intramammary infections during the dry period and early lactation, as compared to quarters treated with antibiotic alone (control). Secondary objectives were to describe the effect of treatment on the prevalence of intramammary infection after calving, the incidence of clinical mastitis events between dry-off and 60 days in milk (DIM), and linear score (LS) after calving.
Growth of female dairy calves fed neomycin and oxytetracycline in milk replacer
Authors: Warnick L. D. , Maul J. , Chan M. , Rosenbaum A. , Still K. , Reyher K. , Guard C. L. , Smith M. C.
Published: February 2023

Public concern about antimicrobial resistance of foodborne pathogens has led to a re-evaluation of the costs and benefits of feeding antimicrobial agents to livestock. The potential benefits of restricting antimicrobial feeding should be evaluated in light of effects on animal health, growth and economic efficiency of production. Previous experiments in research herds showed that feeding milk replacer containing antibiotics increased growth rates of calves, but data are lacking from commercial dairy farms. The purpose of our study was to evaluate the effect of feeding oxytetracycline and neomycin in milk replacer on growth in dairy heifers from birth to four months of age.
Ethics of Pirated Drug Use and How do You Deal with it in Your Practice
Authors: Bertone Joseph J.
Published: February 2023

Over the past 13 years, I have examined some 150 ethical issues that arise in veterinary medicine, either directly in my Canadian Veterinary Journal column or in the ethics column I edit for the Veterinary Forum. While some of these issues represent true dilemmas, with strong arguments that can be marshalled on each side, many others are quite straightforward and their ethical resolution is unambiguous.

I cannot think of a better example of an issue with clear ethical resolution than the one facing us in this discussion-the use of counterfeit (pirated) drugs where veterinarians dispense copies of established veterinary drugs. The basic reason this is a problem is that drugs compounded from bulk ingredients-unlike the branded (FDA approved) products or approved US generic equivalents-do not undergo FDA approved testing for safety and efficacy, and are not produced under conditions that conform to FDA's Good Manufacturing Practices. In my view, dispensing such drugs, as done by many veterinarians to increase profit well above what they can make with approved drugs, violates every sort of moral obligation inherent in veterinary medical ethics.
Practical Application of Epidemiology in Veterinary Herd Health/production Medicine
Authors: Booker Calvin W. , Loneragan Guy H. , Guichon P. Timothy , Jim G. Kee , Schunicht Oliver C. , Wildman Brian K. , Pittman Tom J. , Fenton R. Kent , Janzen Eugene D. , Perrett Tye
Published: February 2023

Practical application of formal epidemiology can be a very useful tool in private practice for food animal veterinarians working in the field of herd health/production medicine. Careful and deliberate determination of the outcome variables of interest in each production situation or application provides a logical starting point for establishing the information requirements necessary to measure the defined outcome variables. Subsequently, the collected data can be used for a wide variety of purposes, including disease investigation, monitoring, forecasting and commercial field trials. The successful application of formal epidemiology in herd health/production medicine can serve as a solid basis for establishing long-term productive business relationships with animal agriculture enterprises.
Epidemiologic Approaches for Measuring and Understanding Abortion in Dairy Cows
Authors: Thurmond Mark C.
Published: February 2023

This paper offers methods for measuring abortion risk and undertaking abortion diagnostic investigations. In addition, some of the associations found between demographic and reproductive features of the dam and subsequent abortion are described. The cohort life table method is used to compute risk of fetal loss (abortion) for pre-defined time intervals (eg. days or weeks) during the gestation period, as well as overall proportion of cows that abort. In contrast, the abortion density method calculates abortion risk for a defined calendar time (eg. per month) as the number of abortions per cowdays- at risk. Both methods are standardized to account for the changing number of cows at risk of abortion, as a result of culling, death, abortion, and calving. Thus, both methods will produce higher and more realistic estimates for abortion risk than are typically calculated. These measures and statistical modeling have been used to estimate the expected magnitude of abortion for dairies (ranging from 8% to 19%) and to identify associations between demographic or reproductive features of the dam and subsequent risk of abortion. Some factors discussed are effects of a previous abortion, dam gravidity and age, days open at time of conception, and season. Analytic methods also are presented for herd-based diagnosis of abortion related to infectious agents or other exposures. These methods permit estimates of the risk, or proportion, of abortions attributable to exposure to an infectious agent or to other putative abortifacient agents.
Controlling What We Can Control
Authors: BonDurant Robert H.
Published: February 2023

While there is sometimes a feeling of hopelessness when we are asked to solve a herd problem involving "occult" loss of pregnancies, there are a few things we as veterinarians can do to reduce the risk of embryonic and fetal losses. For many infectious causes of pregnancy attrition, there are vaccines of various safety and efficacy. Some of them are effective because elegant research on host-pathogen interactions has pointed the way to exquisitely specific and effective antigens and adjuvants; some are effective in spite of a lack of such information; and a few are not particularly effective. But not all pregnancy losses are the direct result of fetal infections. This paper will attempt to address the increasingly long list of causes of pregnancy disruption in cattle, and to point out some preventive measures reported to be effective, or in the case of some as yet unproven interventions, at least make pathophysiologic sense. Topics will include measures to diminish the impact of non-infectious causes of pregnancy disruption (trauma, heat stress, twinning, plant and other ingested toxins); a few infectious causes where preventive intervention is likely to pay off (e.g. infectious bovine rhinotracheitis (IBR), bovine viral diarrhea (BVD) venereal campylobacteriosis, leptospirosis); some "iffy"areas where the payoff is not as certain; and a discussion of the expectations of a vaccine against any reproductive pathogen. A brief mention will be made of some current thinking on efforts to reduce early pregnancy loss through nutritional management of dairy cows.
Rapid Detection of Bovine Viral Diarrhea Virus using a Conductometric Biosensor
Authors: Grooms D. L. , Muhamammad-Tahir Z. , Alocilja E. C.
Published: February 2023

Bovine viral diarrhea virus (BVDV) is one of the most important viral pathogens of cattle worldwide. A key to controlling BVDV is identifying and eliminating carriers of the virus, better known as cattle persistently infected (PI) with BVDV. PI's shed large amounts of virus and serve as the major source of virus transmission within and between farms. Several laboratory methods are currently available to detect PI's including virus isolation, antigen capture ELISA's, skin immunohistochemistry/fluorescent antibody and PCR. The development of a rapid and cost effective field based system to detect PI's would be beneficial for more practical implementation of BVDV control strategies. In this study, a conductometric biosensor previously developed for use in detecting foodborne pathogens was adapted to detect BVDV in cell culture media and blood. The architecture of this biosensor allows for rapid field based applications.
Periparturient Neutrophil Function Suppression is Associated with Endometritis and Fever in Lactating Dairy Cows
Authors: Hammon D. S. , Evjen I. M. , Goff J. P. , Dhiman T. R. , Walters J. L.
Published: February 2023

Endometritis and fever are common health disorders that affect dairy cows during the immediate postparturient period and are temporally associated with periparturient immune suppression. The aim of this study was to test the hypothesis that endometritis and fever in dairy cows are associated with suppressed neutrophil functions during the periparturient period.
Evaluation of Rectal Temperature and Calving Related Factors on the Incidence of Metritis in Postpartum Dairy Cows
Authors: Benzaquen M. E. , Risco C. , Archbald L. F. , Thatcher M. J. , Thatcher W. W.
Published: February 2023

Metritis is a serious condition in dairy cows since it affects production, fertility and can be life-threatening. A better understanding of calving-related factors that predispose cows to metritis would aid in prevention, diagnosis and treatment of this condition. The objectives of this study were to: 1) evaluate the association of calving status, parity and season on the incidence of postpartum metritis in lactating dairy cows; 2) examine the role of rectal temperature as a predictor of this condition; and 3) document the effect of metritis on subsequent reproductive performance.
Use of Environmental Sampling as a Herd Screening Diagnostic Tool for the Detection of Mycobacterium avium Subsp paratuberculosis on Minnesota Dairy Farms
Authors: Raizman E. A. , Wells S. J. , Godden S. M. , Bey R. F. , Oakes M. J. , Bentley D. C. , Olsen K. E.
Published: February 2023

Johne's disease (JD) is a chronic and progressive intestinal disease in ruminants caused by Mycobacterium avium subspecies paratuberculosis (Map). The usual route of infection is fecal-oral. The disease manifests in adult cows and results in economic losses. Although Map does not propagate in the environment, it survives for long periods in different environmental conditions expected on many dairy farms. Johne's disease control programs have been developed in different countries and in several US states with a goal to test and classify herds of cattle as infected or presumptively noninfected with maximum accuracy and least cost. Generally, these programs utilize recognized laboratory tests such as ELISA or direct microbiological individual fecal culture. However, these tests have several disadvantages, especially when applied in herds with subclinical disease or low prevalence. Since Map is shed into the environment by dairy cattle through fecal contamination and appears to survive well, a better understanding of Map distribution in the environment could lead to improved herd-screening alternatives.

Objectives of the study were: 1) to describe Map distribution and prevalence in the environment on Minnesota dairy farms, and 2) to assess the relationship between culture status of Map in the farm environment and fecal-pooled culture status on dairy farms.
Risk Factors for Johne's Disease in Ontario Dairy Herds
Authors: Hendrick S. H. , Duffield T. F. , Kelton T. F. , Leslie K. E. , Lissemore L. K. D. , Archambault M.
Published: February 2023

Treatment of Johne's disease is not efficacious or economical for a commercial dairy herd. Efforts should instead be placed into management of the disease. However, prevention and control of Johne's disease can only be achieved if the risk factors are clearly identified. The objective of this study is to evaluate herd-level risk factors associated with the prevalence of Johne's disease in Ontario dairy herds.
Relationship Between Disease Occurrence, Feeding Management and Return Over Feed in Ontario Dairy Herds
Authors: McLaren C. , Lissemore K. , Leslie K. , Duffield T. , Kelton D. , Grexton B.
Published: February 2023

On a worldwide basis, dairy industries of most countries are becoming increasingly concerned with factors that impact return on investment. Historically, research has focused on the relationship between management, production-limiting disease and milk production. However, few studies have quantified their association with herd economics.

The objectives of this research are to examine the relationship between profitability as measured by the Ontario Dairy Herd Improvement (DHI) Corporation's Return over Feed (ROF) index, and herd characteristics such as milk production, somatic cell count linear score and health management practices. The ROF index will also be used to assess on-farm health and disease information that includes lameness, clinical ketosis, clinical mastitis, retained placenta (RP), displaced abomasum (DA), milk fever, monensin use and ration particle size. Herd level incidence risks for subclinical ketosis and subclinical mastitis will be evaluated by using the California Mastitis Test and the KetoTestO ketone test in early postpartum cows. Subsequently, the associations between the risk of disease, management factors and ROF will be determined.
Mycoplasma in Beef Cattle in Ontario
Authors: Kotzeff Peter
Published: February 2023

Mycoplasma disease complex or Chronic Pneumonia Polyarthritis Syndrome (CPPS) has become widespread in North American feedyards. CPPS presents as a progressive, non-responsive pneumonia and/or an acute onset non-responsive tenosynovitis. In Ontario many producers, as a result of CPPS, now expect a 2-3% death loss (up from 1 %) in high risk cattle. Aggressive and varied feedyard vaccination and treatment strategies have not prevented the increase in health costs. That other management factors may be more important is evident because a subgroup of producers can start high risk cattle and consistently experience lower than average losses and health costs. The identifiable factors associated with improved animal health are described. Producers experiencing unacceptable animal health costs who are unable or unwilling to make the necessary management adjustments must either purchase lower risk animals or absorb the higher cost associated with CPPS.
Practitioners Experience with Mycoplasma bovis Outbreaks
Authors: Muller Fred J.
Published: February 2023

Mastitis due to infection with Mycoplasma bovis is a fairly common occurrence in large, expanding dairy herds. While mycoplasma infections eventually show up in almost all herds, including "closed" herds, it is more commonly seen in herds containing cattle purchased from unknown sources. Mycoplasma mastitis can be extremely contagious and has earned a reputation for causing major outbreaks of untreatable mastitis. Whether or not a single mycoplasma infection develops into a major herd outbreak depends largely on the milking and hospital procedures used by the dairy.
Labor Management
Authors: Shelton Ben
Published: February 2023

For many of us, the dairy industry has changed dramatically in the last 20 years. Herd sizes have become larger and technological development has changed the owner from a man taking care of a few cows to a man with a multi-million dollar business and many employees to get the work done. Managing cows has become managing people. Just like the large successful companies in this country, dairies are spending more time and money in training and motivating people to be productive in a wide range of skills.
Comparison of Three Therapeutic Methods of Cystic Ovaries in Holstein Cows
Authors: Bolourichi M. , Akbarshahi A. , Niasari-Naslaji A. , Hovareshti P. , Tajik P.
Published: February 2023

Hormonal preparations that release luteinizing hormone from the anterior pituitary or have luteinizing hormone-like action are used to treat follicular cysts. GnRH belongs to the former group and human chorionic gonadotrophin (hCG) hormone is in the latter group. Treatment with a luteolytic agent, prostaglandin F2a (PGF2a), is successful if a luteal cyst is diagnosed properly.
Signs and Prognosis of Male Cattle with Urethral Occlusion
Authors: Gronau S. , Rademacher G. , Klee W.
Published: February 2023

The causes for disturbances of emptying of the urinary bladder can be either neurogenic or mechanical. Among the latter, large empyemata ("abscesses") of the urachus (which inhibit emptying of the bladder), and reductions of urethral lumen (occlusions) are more common than obstruction of the bladder, at least among patients of our clinic. Urethral occlusions can have luminal (obstruction or stricture) or extra-luminal (compression stenosis, e.g. by a hematoma of the penis, or malformations) causes. Urethral obstruction (i.e. partial or complete blockage of the urethral lumen from within) is usually caused by urinary calculi. As there are other causes for urethral obstruction which differ from obstructive urolithiasis both in signs and prognosis, a prospective study was undertaken with the objective to create a detailed description of the clinical signs in cattle with urethral occlusion and to define prognostic indicators.
Relationship Between Antibiotic Susceptibility of Mastitis Pathogens and Treatment Outcomes
Authors: Hoe Fernanda G. H. , Ruegg Pamela L.
Published: February 2023

The efficacy of mastitis therapy depends on inherent characteristics of the pathogen, the duration of therapy, host factors and the concentration of antibiotic that can be maintained at the site of infection. Susceptibility tests of mastitis pathogens are often used to guide treatment decisions, but the clinical relevancy of susceptibility testing has been challenged. The objective of this study was to determine the relationship between minimum inhibitory concentration (MIC) of mastitis pathogens and outcomes of clinical mastitis.
Herd and Spatial Factors Affecting the Proportion of False-Positive Results on the Caudal Fold Tuberculin Test in Michigan Cattle
Authors: Norby B. , Bartlett P. C. , Kaneene J. B. , Grooms D. L. , Granger L. M.
Published: February 2023

Bovine tuberculosis skin tests have been used successfully for control and eradication of bovine tuberculosis in the United States since the eradication program was begun in 1917. In 1992, there were only 10 states that had not achieved tuberculosis-free status. Unfortunately, bovine tuberculosis has become endemic in the cattle population in certain areas in the United States, including the northern part of the Michigan's Lower Peninsula. The caudal fold test is a key element of herd-level and individual animal screening. The specificity of the caudal fold tuberculin test is not perfect, and has been estimated to be approximately 89-96%. It is also evident that the specificity of the caudal fold tuberculin test is not a constant in different cattle populations. Variation in specificity may be due to differences in the amount and concentration of the tuberculin used for the test, regional variation in cross-reacting mycobacteria that cause false-positive results on the caudal fold tuberculin test, and variation in the interpretation of the test results by the testing veterinarians. The objective of this study was to use available data from the bovine tuberculosis testing program in Michigan to evaluate possible associations between the proportion of false-positive results on the caudal fold tuberculin test, and factors regarding geography and type of herd.
Comparison of Bacteria Populations within Clean and Recycled Sand used for Bedding in Dairy Facilities
Authors: Kristula M. A. , Rogers W. , Hogan J. S. , Sabo M.
Published: February 2023

Sand is widely considered the best bedding for cow comfort and udder health. Advances in manure handling technology has enabled sand to be separated from manure by either active (mechanical sand separator) or passive (gravity) means. The objective of this study is to evaluate the safety of recycled sand as a bedding material for dairy cows.
Effect of Rubber Flooring on the Development of Claw Lesions in Lactating Dairy Cows Housed in Free Stall Barns
Authors: Vanegas J. , Overton M. W. , Sischo W. M. , Berry S. L.
Published: February 2023

With the increased numbers of confinement dairy production systems, lameness has become a major economic cost to the dairy industry. Housing factors, specifically related to concrete flooring in free stall barns, have been associated with an increased risk of claw lesions and clinical lameness. Research has suggested that alternative flooring surfaces may prevent or decrease the occurrence of lameness and claw lesions. The objective of this study was to determine the effect of rubber flooring on the occurrence of claw lesions, clinical lameness and hoof growth and wear.
Effect of Parturition Induction of Term Pregnancies on Calf Survival, Production and Reproduction in Holstein Dairy Cows
Authors: Villarroel A. , Lane V. M.
Published: February 2023

Longer gestations are correlated with higher birth weights, and larger calves are correlated with an increased rate of stillbirths and dystocias. Cows that experience stillbirths have a higher risk for periparturient diseases such as retained placenta (RP), downer cow syndrome, metabolic diseases, lower milk production, decreased fertility and higher risk of dying or being culled. Preventing long gestations via parturition induction may prevent delivery of larger calves and dystocia in cows. Parturition induction has been reported as a management tool to maximize utilization of pastures in Australia and New Zealand. In that situation, all cows are induced to calve or abort independent of their gestation length, causing high incidence of RP and lower milk production in the subsequent lactation.

We hypothesize that a single dose of dexamethasone given to induce parturition in cows that are past the average due date (1) will decrease perinatal calf and dam mortality; (2) will decrease the incidence of RP; and (3) will have no negative effect on milk production in the subsequent lactation when compared to non-induced cows.
Characterization of Bovine Viral Diarrhea Virus (BVDV) Genetics, Antibody Response and Viremia from a Group of BVDV Persistently Infected Calves
Authors: Chase C. C. L. , Braun L. J. , Holler L. , Neill J. , Ridpath J.
Published: February 2023

Bovine viral diarrhea virus (BVDV) infections cause major problems in the US cattle industry. BVDV persistent infections are the result of fetal infections in the first trimester of pregnancy. Persistently infected animals are a major reservoir of the virus in nature and  are extremely efficient at spreading the virus among cattle populations. Understanding the nature of persistent infections and developing diagnostics and surveillance schemes that eliminate PI animals is vital to the control of BVDV. In this study we look at variations in clinical presentation, viral spread, immune response and viral stability in a large group of calves infected with the same BVDV strain.
Seroprevalence of Johnes Disease, Neospora caninum and Bovine Leukosis Virus in Canadian Cow-Calf Herds
Authors: Campbell J. R. , Power C. , Hood R. , Olaloku N. , Mainar-Jaime R. , Waldner C.
Published: February 2023

The objective of the Canadian Beef Production Limiting Diseases project was to conduct provincial serological surveys across Canada for production limiting diseases in cow-calf herds. The diseases were chosen because they are three diseases known to occur in Canada and all have subclinical carrier states. Each of these diseases has significant economic implications in terms of trade or reduced productivity, and none are easily controlled using conventional treatment methods. The diseases chosen to estimate prevalence for were bovine leukosis virus (BLV), Mycobacterium paratuberculosis (Johne's Disease) and Neospora caninum (Neosporosis). Provincial surveys had already taken place in dairy cattle, and two provinces (Manitoba and Quebec) had already performed surveys of beef cattle.
Estimate of the Proportion of Beef Cattle Herds with Mycobacterium avium subspecies paratuberculosis-Infected Cattle and Associated Risk Factors
Authors: Smith David R. , Schomer Thomas J. , Hinkley Susanne , Clowser Sharon , Galeota Judith A. , Weiss James C. , Akin Kathleen J.
Published: February 2023

Mycobacterium avium subspecies paratuberculosis (MAP), the agent of Johne's disease, spreads through beef cattle herds with little awareness by beef cattle producers. The objectives of this study were to accurately estimate the proportion of beef cattle herds with 5% or more of the adult herd infected with MAP, and to identify herd-level practices and conditions associated with Johne's disease herd status so that veterinarians could help beef cattle producers accurately assess and/or modify their risk for introducing MAP into, and allowing it to spread within, their herds.
Relationship Between Pre-fresh NEFAs, Fresh Butterfat Percentage, Progesterone Levels Following Pre-Synch and Pregnancy Rates
Authors: McCarthy K. K. , Neuder L. M. , Joshi N.
Published: February 2023

As herd size and milk production increase on modern dairies, it seems to be at the expense of fertility, increasing days open, declining pregnancy rates and rising cost associated with each pregnancy. To determine which service was the best time to use more expensive semen, a large commercial dairy in central Michigan investigated progesterone levels in cows following a Presynch protocol. This was followed by a prospective study, beginning with cows in the dry period, with the objective of relating pre-breeding progesterone levels to risk factors in the transition period.
Owner-reported Incidence of Clinical Salmonellosis in Northeastern Dairy Herds
Authors: Rosa B. V. , Warnick L. D. , Cripps C. J. , Nydam D. V. , Reed K. E.
Published: February 2023

Bovine salmonellosis is important because of clinical effects and zoonotic potential. Our objectives were to determine the frequency of owner-reported salmonellosis in northeastern US dairy herds and to examine the relationship of salmonellosis with herd size and housing type.
Commingling Dairy Cows
Authors: Nordlund Ken , Cook Nigel , Oetzel Garrett
Published: February 2023

In modern confinement dairies, cows move between groups depending on management needs for special rations and special handling requirements. With each move, each cow must establish rank within the new group. Extended stays in pens characterized by new arrivals every day appear to present substantial health risks to some cows. Overstocked pens present challenges regarding both stall and feed bunk access. Provision of 30 inches (76 cm) of bunk space per cow in the weeks before and after calving, and minimizing pen moves, appears to be consistent with improved fresh cow health and productivity.
Case of Papillomatous Digital Dermatitis in Feedyard Cattle
Authors: Lubbers Brian V. , Apley Michael
Published: February 2023

Papillomatous digital dermatitis may be an emerging disease within the feeder cattle industry. This case report will review the presentation, diagnostic plan and some of the available treatment options as well as describe an atypical presentation of this disease.
Sync Programs and Ultrasound
Authors: Fricke Paul M.
Published: February 2023

Early identification of non-pregnant dairy cows and heifers post-breeding can improve reproductive efficiency and pregnancy rate by decreasing the interval between artificial insemination (AI) services and increasing AI service rate. Thus, new technologies to identify non-pregnant dairy cows and heifers early after AI may play a key role in management strategies to improve reproductive efficiency and profitability on commercial dairy farms. Transrectal palpation is the oldest and most widely used method for early pregnancy diagnosis in dairy cattle7 • However, a newer technology may someday replace transrectal palpation as the method of choice for pregnancy diagnosis in the dairy industry. Before this transition can occur, two events must transpire. First, a technology must be developed that exceeds transrectal palpation in one or more of the characteristics of the ideal early pregnancy test. Second and no less important, this new technology must be practically integrated into a systematic, on-farm reproductive management strategy and empirically demonstrated to exceed the status quo of the industry (i.e., transrectal palpation) in reproductive performance. Results from a recent study indicate that positive pregnancy outcomes diagnosed by transrectal ultrasonography conducted 26 days after timed AI (TAI) may be inflated due to pregnancy loss, compared to pregnancy outcomes conducted 33 days after TAI. Furthermore, fertility to TAI after re-sychronization of ovulation was greater when initiated 33 days after TAI compared to 26 days. These results suggest the counterintuitive notion that delaying pregnancy diagnosis from 26 to 33 days post-TAI may improve reproductive efficiency when using a hormonal protocol for timed AI to program non-pregnant cows for rebreeding. This is due to the high rate of pregnancy loss occurring in cows diagnosed pregnant at 26 versus 33 days post-TAI.
Improving Decision Making by Consideration of Type I and Type II Error Costs
Authors: Overton Michael W.
Published: February 2023

Dairy producers must make good decisions regarding potential new products or interventions in order to optimize profitability. Choosing to use a product that does not yield a profitable response is an example of a type I error. The concept of minimizing type I error cost by good decision making is usually intuitive. However, the concept of"lost opportunity cost" is a bit more nebulous. The choice of not using a product that in reality would have returned a profit is an example of a lost opportunity or a type II error cost. Calculation of the error costs for a single product with sound research is straightforward. Applying this concept to reproductive interventions is more problematic due to the difficulty in measuring the value of reproductive change. The model presented in this paper attempts to quantify the value of improved reproductive performance by estimating the value of the change in milk production, the value of calves produced, and the effects of culling changes. Application of type I and type II error theory to the question of "should TAI be used" yielded different results in the two examples. In the first scenario, the conclusion reached was that overall, herds with a baseline pregnancy rate (PR) of 16% or less utilizing AI based upon detection of estrus should carefully consider the use of TAI based on the large advantage of type II vs type I error costs. However, in scenario two, herds that have already achieved a PR of 17% have less to gain economically by making the reproductive management change.
Transitional Nutrition for Sinall Ruminants
Authors: Van Saun Robert J.
Published: February 2023

The time around parturition is the single most stressful event in a doe's or ewe's reproductive life cycle. Nutritional insults prior to and following parturition can result in exacerbation of key metabolic changes necessary to make the physiologic transition from pregnancy to lactation, resulting in a myriad ofnietabolic diseases. Current perceptions tend to focus attention on the lactating female and nutritional support of milk production; however, nutrition and management of the late pregnant female has more significant impact on her productive efficiency, both reproductive and lactational. Veterinarians can play an important role in their client's small ruminant transition program through nutritional monitoring of body condition score, forage quality and metabolic parameters of energy balance and protein status.
Case Study
Authors: Van Saun Robert J.
Published: February 2023

A large sheep flock was experiencing a high prevalence of metabolic diseases early in the lambing season. Pregnancy toxemia and secondary hypocalcemia were diagnosed based on history, physical examination and serum biochemistry results. A new approach to metabolic profiling, using pooled sera samples to reduce costs, was used to assess nutritional status of the flock. Ewes close to the time of lambing were found to be in severe negative energy balance, resulting in excessive fat mobilization and clinical signs associated with pregnancy toxemia and hepatic lipidosis. Inadequate amount of fermentable carbohydrates, which could provide glucose to support late pregnancy requirements, was determined by nutrient analysis. Lower cost by-product feeds had been substituted into the new pellet formulation. Although feed costs are a substantial component of production costs, feed changes based solely on cost may not be appropriate relative to nutritional needs and animal health.
Technician Utilization
Authors: Kral Jannell
Published: February 2023

The veterinary technician is an integral member of the veterinary health care team. We have been educated in the care and handling of animals, the basic principles of normal and abnormal life processes, and routine laboratory and clinical procedures. All veterinary technicians work under the supervision of a licensed veterinarian. While a veterinary technician can assist in performing a wide variety of tasks, they cannot diagnose, prescribe, perform surgery, or engage in any activity prohibited by a state's practice act.
Determination of Papillomatous Digital Dermatitis (PDD) Prevalence in the U.S. Feedlot Industry through Practitioner Survey
Authors: Lubbers B. V. , Apley M.
Published: February 2023

Papillomatous digital dermatitis has been recognized and studied within the dairy industry for nearly 30 years. Published literature describing the incidence, risk factors, treatment and probable etiology within dairies is readily available. Far less information is available concerning papillomatous digital dermatitis and its effects on the US feedlot industry. Although papillomatous digital dermatitis is rarely reported in feedlot cattle, there have been at least three confirmed cases in feedlots in Kansas and Iowa.
Effects of Two-Week Oral IGG Supplementation in Pre-Weaned Calves on Morbidity, Mortality, and Weight Gain
Authors: Moore D. A. , Berge A. C. B. , Acre S. , Sischo W. M.
Published: February 2023

Because of growing concern over antimicrobial resistance, alternatives to antimicrobial use in animal production are needed. One potential way to reduce treatment is to provide improved caloric and IgG supplementation in the neonatal period. The objectives of this study were to determine the effect of 14 days of an oral dehydrated colostrum supplement added to milk-replacer for pre-weaned calves on calf morbidity and treatments, mortality, feed intake and weight gain.
Use of a Fecal PCR Assay on Environmental Samples for Detection of Dairy Cattle Herds Infected with Johne's Disease
Authors: Cernicchiaro N. , Wells S. J. , Muñoz-Zanzi C. , Gaulke J. , Wees C.
Published: February 2023

The goal of this study was to evaluate the application of fecal PCR assay for diagnosis of Mycobacterium avium subspecies paratuberculosis in environmental samples and to determine its sensitivity for detection of dairy cattle herds infected with JD
New Device for the Collection of Bovine Semen
Authors: Dehn C. A. , Prien S. D. , Johnson D. L.
Published: February 2023

In general, the act of collecting semen for artificial insemination takes semen from its protected storage environment in the male and thrusts it into the unprotected environment of a specimen collection tube. Even with rapid processing, this leads to drastic shifts in temperature and pH, resulting in a quick deterioration of semen parameters and programmed cell death. This laboratory has developed a species-specific modified collection device (MCD), which was designed to optimize semen parameters by controlling temperature, pH and osmotic stress. In previous studies in the equine, canine, ovine and humans, using the new collection container/technique has resulted in improved semen parameters which are maintained over extended periods of time when compared to the traditional collection methods. Further, in a breeding trail in the equine, fertility rates of fresh semen were maintained for extended periods of time over the control. The objective of the current study was to further investigate the usefulness of the modified device in improving semen parameters and fertility rates in the bovine.
Parameters of Ear Notch Samples for BVDV Testing
Authors: Ridpath J. F. , Hessman B. E. , Neill J. D. , Fulton R. W. , Step D. L.
Published: February 2023

Infection with bovine viral diarrhea viruses (BVDV) is a major source of economic loss for the US cattle industry. Houe (2003) estimates that losses in areas where BVD is endemic range between $10 to 40 million per million calvings. Results of serology surveys in the US suggests that our losses are in the upper end of this range (Houe et al, 1995a; Houe et al, 1995b; Paisley et al, 1996). In 2004, 37.6 million calves were born in the US; thus, US losses by this estimate would be between $376 million to 1.5 billion for 2004. The 2005 calf crop was ~37.8 million, making the 2005 estimate very similar to that of 2004.

While BVDV infections are well recognized as reproductive pathogens among dairy producers, producers are less aware that BVDV infections are also associated with increased respiratory disease, increased severity of secondary infections and decreased milk production. Persistently infected (PI) animals are the major vectors for spreading BVDV within and among herds. Based on studies of dairies of 100 cows or more, Joly et al (2005) estimated that the presence of one PI animal in a herd resulted in a loss of $1.93/cwt of milk sold. Studies estimate that 10-15% of US herds have at least one PI animal (Houe et al, 1995c; Wittum et al, 2001). In 2004, US dairies produced 170,805 million lb (77,638 kg) of milk. If 10% to 15% of dairy herds have at least one PI animal, then the cost to milk production is between $330 to 494 million per year.

Control efforts in the US are geared towards identifying and eliminating Pis. Several tests based on detection of either antigen or viral RNA in blood, serum, bulk milk or skin biopsies are currently in use (Cornish et al, 2005; Fulton et al, 2006). Ear notch samples have become the tissue of choice for screening for PI animals because 1) they are easy to collect; 2) equipment requirements are minimal; 3) they are not affected by presence of passive antibodies; and 4) they can be used as the sample for a wide variety of tests including immunohistochemistry, real-time polymerase chain reaction and antigen-capture ELISA.

While ear notches have become one of the samples of choice, there is little information available regarding sample size requirements and stability. Further, while pooling of ear notch samples has been proposed for reducing the cost of surveillance programs (Kennedy et al, 2006), the viral load available for detection from ear notch samples is largely undetermined. The purpose of this study was to establish working parameters for sample size, viral detection limit and sample storage conditions for real-time PCR and antigen-capture ELISA.
Johne's Disease: Mycobacterium paratuberculosis Super-shedders
Authors: Whitlock R. H. , Gardner I. A. , Mangold B. L. , Smith J. , Sweeney R. W. , Schukken Y. , Van Kessel J. , Hovingh E. , Karns J. , Wolfgang D. , Fyock T.
Published: February 2023

This report further documents the critical importance of identifying super-shedders, since they contribute billions of MAP CFU daily to the environment, serving to disseminate MAP to susceptible cattle. In many herds, this results in significant numbers of culture-positive fecal samples through passive shedding. The frequency of super-shedders among culture-positive cattle in infected herds is unknown. However, our preliminary investigations have shown that each of three current herds has at least one super-shedder cow, with five super-shedder cows having been identified among the 7.1% ( 41 of 575) of culture-positive cattle in the herds. Our preliminary estimates are that 10% of heavy shedders (or about 2 to 3% of all culture-positive cattle at a single time-point) may be super-shedders, excreting >10 billion CFU MAP per cow per day.
Neospora
Authors: Gay John M.
Published: February 2023

Although more research is needed to improve our understanding of the epidemiology of bovine neosporosis, our current knowledge is likely sufficient for developing effective control and monitoring strategies. The decision of whether or not it makes sense to monitor and control the infection in a given herd depends on a complex set of factors that differ between herds and regions. Control likely should be considered in the light of resource limitations, management goals and other problems and opportunities faced by the herd. Several authors have suggested that practitioners should consider performing a cost-benefit analysis on each herd to determine the critical prevalence threshold for undertaking a herd control program and to determine the best strategy. Currently the optimal control method appears to be testing potential replacements for seronegativity prior to their selection, but the optimal strategy will likely change with increased understanding, and as improved vaccines and even therapies emerge.

Simplicity does not precede complexity, but follows it.

(Alan Perlis)
Comments on Classical and Atypical Scrapie in Domestic Sheep and Goats
Authors: Spraker Terry R. , O'Rourke Katherine I.
Published: February 2023

Scrapie is a neurodegenerative disease in domestic sheep and goats. Scrapie has a long incubation period that can vary from two to five years. The etiology is an extremely stable isoform (PrP8c) of the normal cellular prion protein (PrPc). The accumulation of this protein in the brain is thought to result in the spongiform encephalopathy that characterizes the disease. Scrapie has been reported in the United Kingdom, Ireland, most European countries, Canada, the United States, India and Japan, but not in Australia and New Zealand. Clinical signs are mostly neurological and diagnosis is usually made with immunohistochemical staining of the brainstem and retropharyngeal lymph nodes. Genetics plays a significant role in the susceptibility and incubation period of the disease and is used in control strategies. The primary method of prevention is maintenance of a closed ewe flock, purchase of sheep from uninfected farms enrolled in an approved flock certification program, or purchase of genetically resistant stock. Following diagnosis of scrapie in a flock, depopulation of genetically susceptible sheep is the only effective control measure at this time. If a sheep or goat flock is diagnosed with atypical scrapie the herd is depopulated.
Effect of Feeding One or Two Doses of a Colostrum-Derived Commercial Colostrum Replacer on Passive Transfer of Immunoglobulin Gin Newborn Dairy Calves
Authors: Godden S. , Haines D. , Bey R.
Published: February 2023

Colostrum is the single most important management factor determining calf health and survival. Calves experiencing successful passive transfer of colostral immunoglobulins (serum IgG > 10.0 mg/ml) have improved preweaning health and survival, improved growth rate and feed efficiency, reduced age at onset of puberty, reduced age at first calving, and improved first and second lactation milk production. Unfortunately, many producers continue to suffer significant losses related to poor colostrum management. Factors affecting the success of a colostrum management program include 1) Quality of colostrum fed, 2) quantity of colostrum fed, 3) quickness of providing the first colostrum feeding and 4) cleanliness of colostrum (i.e. bacterial contamination). Use of commercial colostrum replacement products may offer multiple advantages, including consistent quality, convenience, and cleanliness. However, it is important to evaluate the ability of commercially available colostrum replacement (CR) products to achieve successful passive transfer of immunoglobulin G (lgG) in calves managed under field conditions. The objective of this study was to describe passive transfer of lgG in newborn calves fed one or two doses ( 100 gm IgG or 200 g IgG) of a commercial colostrum-derived colostrum replacement (CR: Land O'Lakes Colostrum Replacement®, Land O'Lakes Animal Milk Products, St. Paul, MN) or 4 quarts of maternal colostrum (MC).