bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevention of Bovine Viral Diarrhea Virus Persistent Infection after a Heterologous Type 1 or Type 2 Challenge in Animals Vaccinated with a Combination Modified Live Virus Vaccine Containing Bivalent BVDV
Authors: Fogarty-Fairbanks K. K. , Rinehart C. L. , Ohnesorge W. C. , Loughin M. M. , Chase C. C. L.
Published: February 2023

Bovine viral diarrhea virus (BVDV) infections in cattle result in a broad spectrum of clinical syndromes ranging from asymptomatic infections to peracute hemorrhagic disease with high mortality. Acute BVDV infection causes respiratory, gastrointestinal and/or reproductive disease that results in a febrile response along with leukopenia. Due to BVDV shedding, persistently infected (PI) animals are a long term threat to herdmates, and may develop mucosal disease resulting in the death of the animal.

Acute BVDV infection of pregnant cattle with either cytopathic (CP) or noncytopathic (NCP) BVDV can result in a variety of fetal syndromes, depending on the virulence of the strain and age of the fetus. In early gestation, BVDV infection can result in early embryonic death and fetal absorption. Between 40-125 days of gestation, infection with NCP BVDV can result in PI calves that shed NCP BVDV for their entire lives.

The purpose of this study was to determine the efficacy of a commercial MLV combination vaccine containing bivalent BVDV diluted to contain minimum protective levels of BVDV type 1 and 2 in providing fetal protection against a heterologous challenge with type 1 or type 2 BVDV. Two groups of animals were vaccinated with a single dose of the commercial vaccine. Protection against persistent infection of the fetus was measured following challenge.
Corn Silage And Haylage Variability Within Bunker Silos
Authors: Stone W. C. , Chase L. E. , Batchelder T. L.
Published: February 2023

Forages, and haylages in particular, have a large potential for variation. Variability in dry matter, fiber levels and fermentation profiles within a silo can influence herd performance and animal health. Degree of variation at a given dairy depends largely on its ability to manage cropping and harvesting systems. One advantage that bunker silos have over upright silos and bags is that ensiled feed from a given load or field is spread over a larger area of the silo. Thus, changes in forage dry matter (DM) or chemical measurements occur more gradually than in other storage systems. However, variation can still occur across the height of a silo. To estimate this potential variation, eleven corn silage and nine haylage bunker silos from nine dairies located in central New York were evaluated.
Milk And Plasma β-Hydroxybutyrate Concentrations in Holstein Transition Cows Supplemented with a Monensin Controlled-Release Capsule
Authors: Melendez P. , Goff J. , Risco C. , Archbald L. , Littell R. , Donovan A.
Published: February 2023

Ketosis is a common calving-related disorder affecting dairy cows during the transition period. Subclinical ketosis is characterized by serum β-hydroxybutyrate (BHB) levels > 1000 to 1400 μmol/L. The highest incidence of subclinical ketosis occurs within the first two to three weeks oflactation. The Ketolac® test (Nagoya, Japan) is designed for detection of BHB in milk. Therefore, it is a practical tool for diagnosing subclinical ketosis in early postpartum dairy cows. If prevention is not considered during the transition period, cows will be at higher risk of developing ketosis. Monensin is an ionophore that affects rumen fermentation, resulting in increased propionic acid production with a concurrent decrease in the molar proportion of acetate and butyrate. As a result, monensin has been used to prevent ketosis and calving-related disorders in dairy cattle.

It is hypothesized that dairy cows supplemented with monensin and fed diets containing citrus pulp would experience a decreased incidence of subclinical ketosis. Therefore, the objectives of this study were to determine the effect of a monensin controlled-release capsule applied at dry-off on the proportion of cows with concentrations of milk BHB > 200 μmol/L, and to associate these findings with the concentration of serum BHB at 14 d postpartum in Holstein dairy cows fed diets containing citrus pulp.
Evaluation of Three Cow-side Tests for Detection of Subclinical Ketosis in Fresh Cows
Authors: Carrier J. , Stewart S. , Godden S. , Fetrow J. , Rapnicki P.
Published: February 2023

Subclinical ketosis in dairy cattle can lead to economic losses through decreased milk production, decreased reproductive performance, increased risk of displaced abomasum and increased risk of clinical ketosis. For early detection of the disease, there is a need for rapid and accurate diagnostic tests.

The objective of the study was to evaluate the performance of three cow-side diagnostic tests for the detection of subclinical ketosis in fresh dairy cows, compared to the gold standard serum β-hydroxybutyrate (BHBA). The cow-side tests were: (1) a commonly used test strip detecting acetoacetate in urine (Ketostix, Bayer Corporation, Elkhart, Indiana, USA), (2) a commonly used powder test used on milk, also detecting acetoacetate (KetoCheck, Great States Animal Health, St. Joseph, Missouri, USA), and (3) a milk test strip detecting BHBA (KetoTest, Sanwa Kagaku Kenkyusho Co. Ltd., Nagoya, Japan, distributed by Elanco Animal Health/Provel, Guelph, Ontario, Canada).
Effect of a Monensin Controlled-Release Capsule Inserted At Dry-Off On Energy Status In Transition Holstein Cows Fed Typical Florida Diets
Authors: Melendez P. , Goff J. , Risco C. , Archbald L. , Littell R. , Donovan A.
Published: February 2023

The transition period in dairy cows (three weeks before and after calving) is characterized by tremendous physiological and metabolic changes. During this period, cows experience some degree of hypocalcemia, increased levels of non-esterified fatty acids (NEFA) and Bhydroxybutyrate (BHB), and decreased levels of glucose. Consequently, if prevention is not employed, cows will be at a higher risk of developing calving-related disorders (CRD).

Monensin is an ionophore that affects rumen fermentation, resulting in increased proprionic acid production and a concurrent decrease in the molar proportion of acetate and butyrate. Consequently, monensin as a controlled-release capsule has been used to prevent ketosis and other disorders in dairy cattle.

The hypothesis of the present study was that transition dairy cows supplemented with monensin and fed typical Florida diets would positively improve energy status. Therefore, the objective of this study was to determine the effect of a monensin controlled-release capsule inserted at dry-off on concentrations of NEFA, BHB and glucose during the transition period of Florida dairy cows.
Treatment of Persistent Escherichia coli Mastitis on a Large Dairy
Authors: Sears P. M. , Ackerman C. E. , Crandall K. M. , Guterbock W. M.
Published: February 2023

In our previous clinical mastitis study (Ackerman, AABP 2003), 39% of Escherichia coli intamammary infections persisted more than 21 days. Since E. coli is isolated from less than 20% of clinical cases, persistent E. coli infections make up less than 10% of clinical mastitis cases. A protocol that includes treatment of all cows to address these persistent infections is neither practical nor cost-effective. Currently, many larger farms are not treating E. coli mastitis with antibiotic therapy. However, these infections can be serious and painful with a persistent high milk somatic cell count. In herds where milk from clinical mastitis cases is cultured and pathogens identified before treatment, use of antibiotics for E. coli infections may be both practical and costeffective. These E. coli cases meet the AMDUCA criteria for extra-label treatment of an infection that threatens the animal's well-being and does not respond to approved intramammary antibiotics. In this study, we evaluated two antibiotic treatments for their effect on persistent E. coli infections.
Effect of Management Related Disease Control Methods on the Development of Johne's Disease in Dairy Cattle in Texas
Authors: Villarino M. A. , Jordan E.
Published: February 2023

With the primary objective of evaluating long-term effectiveness and feasibility of management-related disease control methods in large dairies and on beef operations on the development of Johne's disease (JD) in cattle in Texas, USDA-APHIS and Texas A&M University have initiated the Johne's Disease Control Demonstration Project for the Texas dairy and beef industries. The epidemiological and production analysis of one of the dairy demonstration herds (n=3534) is presented, and the effect of JD on the herd's production parameters is evaluated.
Salmonella Antimicrobial Resistance Patterns on Midwest and Northeast Dairy Farms
Authors: Ray K. , Warnick L. D. , Mitchell R. , Kaneene J. B. , Ruegg P. L. , Wells S. J. , Fossler C. P. , Halbert L. W.
Published: February 2023

Potential impact of antimicrobial use in livestock on the development of antimicrobial-resistant zoonotic pathogens is an ongoing and controversial public health issue. Our objective was to determine the prevalence of antimicrobial resistance among Salmonella isolates collected from dairy farms.
Can Mycobacterium avium subspecies Paratuberculosis be Transmitted from Cattle to Deer and Rabbits, and Vice Versa?
Authors: Raizman E. A. , Wells S. J. , Jordan P. A.
Published: February 2023

Mycobacterium avium subspecies paratuberculosis (MAP), the causal agent of Johne's disease (JD), infects both wild and domestic ruminants, especially dairy cows. In cattle, the usual route of infection is fecal-oral, with young cattle becoming infected by exposure to manure from infected adult cattle or their environment. The disease manifests in adult cows and results in economic losses. Clinical paratuberculosis has been diagnosed in a number of free-ranging wild ruminant species, especially in North America and Europe, such as Rocky Mountain bighorn sheep, red deer in the western Alps, key deer, and tule elk. In both cattle and wild ruminants, the gastrointestinal tract is the primary site of infection, predominantly the small intestine. In the United States, infected cattle herds have been considered to be an infection source for wild ruminants. In Scotland, MAP was found in rabbits (Oryctolagus cuniculus) that shared the same pasture infected by cattle, and a significant association was found between the presence of MAP in rabbits and cattle farms with JD. Despite the obvious link between JD in wild ruminants or rabbits and domestic ruminants, especially dairy cows, no study has evaluated the possible risk factors associated with cross infection between wildlife and domestic ruminants. The objectives of this study were to assess risk of transmission of MAP among dairy cattle, deer and rabbits, and to estimate prevalence of MAP among deer and rabbits surrounding infected and uninfected Minnesota dairy farms using fecal culture.
Evaluation of a Rapid Test for NEFA in Bovine Serum
Authors: Gooijer L. , Leslie K. , Duffield T. , LeBlanc S. , Perkins N. , Vernooy E.
Published: February 2023

Excessive or prolonged periparturient negative energy balance (NEB) is an important issue for dairy producers, and may be associated with increased risk of clinical disease and impaired production and reproductive performance. Affected cows commonly have elevated circulating levels of non-esterified fatty acids (NEFA) prior to calving and increased beta-hydroxybutyrate (BHB) postpartum. Monitoring the incidence of subclinical ketosis postpartum has been the recommended method of surveillance for this problem. Prepartum, blood NEFA concentration may be used to detect cows at risk for problems with severe NEB. Serum NEFA greater than 0.4 mEq/L NEFA has been proposed to identify excessive prepartum NEB. Measuring NEFA has traditionally involved submission of serum to a diagnostic laboratory. The DVM NEFA test (Veterinary Diagnostics. Newburg, Wisconsin, USA) is a new, rapid, spectophotometry method to determine NEFA concentration in serum through light absorbance. The objective of this study was to determine the test characteristics of the DVM NEFA test and its usefulness as a method of identifying problems with NEB in prepartum dairy cows.
Pharmacokinetics of Parenteral Vitamin E in Peripartum Dairy Cows
Authors: Bankert M. , LeBlanc S. J. , Leslie K. E.
Published: February 2023

Supplementation of peripartum dairy cattle with parenteral vitamin E has been reported to decrease the incidence of retained placenta and metritis. Our objective was to compare the effect of one subcutaneous (SC) or intramuscular (IM) injection of vitamin E on plasma and neutrophil a-tocopherol concentrations.
Preliminary Results from a Field Study to Investigate the Relationship between Colostrum Quality and Management and Serum Immunoglobulin Concentrations in Dairy Calves
Authors: Godden S. , Bey R. , Malmedal T. , Gerdes J. , Borjesson D. , Wells S. , Chester-Jones H. , Fetrow J. , Stewart S. , Rapnicki P.
Published: February 2023

Results of two large national studies indicate that the national preweaning mortality rate in dairy heifers has improved very little over the past ten years (10.8% in National Animal health Monitoring Systems (NAHMS), 1993, 8. 7% in NAHMS, 2002). Failure to reduce mortality in preweaned dairy heifers is partially attributable to poor colostrum management practices. In 1993 (NAHMS), 41 % of 2177 calves sampled between 24 and 48 hrs of age suffered from failure of passive transfer (FPT), or low serum immunoglobulin G (IgG) concentrations. Numerous studies have demonstrated that failure of passive transfer (FPT; calf serum IgG concentration< 10 mg/ml) is associated with a significant increase in risk for morbidity and mortality in the period between birth and weaning (Fowler, 1999; Wells et al, 1996). Conventional factors considered to be important in an effective colostrum management program have included quantity of colostrum fed, quality of colostrum fed (IgG concentration) and quickness (or age at first feeding). Offering a second feeding of colostrum is also frequently recommended. Recently, calf management experts have also begun to evaluate colostrum cleanliness (total bacteria count or total coliform count) as another potentially important factor. Limited studies have suggested that bacteria counts in colostrum not only serve as a pathogen source, but may also reduce efficiency oflgG absorption in the gut. The objective of the current study was to evaluate the relationship between serum IgG concentrations in dairy calves and the aforementioned colostrum management factors (colostrum quantity, quality, quickness, cleanliness).
Evaluation of the Efficacy of Halofuginone Lactate (Halocur®) as an Aid in the Prevention of Cryptosporidiosis in Ontario Dairy Calves
Authors: Jarvie B. D. , Leslie K. E. , Peregrine A. S. , Wallace M. M. , Duffield T. F. , Weese J. S.
Published: February 2023

Cryptosporidium parvum is a common cause of diarrhea in calves less than one month of age. Prevalence of shedding of C. parvum and clinical disease is high on many dairy farms. Control of cryptosporidiosis is difficult. There are currently no approved products in North America for prevention of this disease. In Europe, halofuginone lactate (Halocur®) is marketed for the prevention of cryptosporidiosis by reducing and delaying excretion of C. parvum oocysts and in preventing diarrhea. The objective of this study was to evaluate the efficacy of halofuginone lactate as an aid in the prevention of cryptosporidiosis in dairy calves.
Retrospective Study of Risk Factors that Affect Outcomes in Bovine Cesarean Sections (1998-2003)
Authors: Newman K. D. , Anderson D. E.
Published: February 2023

Bovine cesarean sections are one of the most commonly performed procedures in bovine practice with a variety of outcomes. A number of risk factors that affect outcomes have been proposed, but substantiated by clinical impression alone. The purpose of this retrospective study was to determine whether there was a difference between elective, emergency non-emphysematous and emergency emphysematous presentations.

The objective was to compare whether the ability to exteriorize the uterus during fetal delivery and/or calf viability at the time offetal delivery have effects on outcome.
Update on Veterinary Breeding Soundness Evaluation of Bulls
Authors: Wolfe Dwight F.
Published: February 2023

What is breeding soundness evaluation of bulls? The term breeding soundness evaluation is often used to describe a bull's ability to get cows pregnant. However, too often there are broad expectations when this term is used. This presentation will discuss those facets necessary to identify bulls that are capable of getting a reasonable number of cows pregnant in a limited breeding season.
Lameness in Cattle
Authors: Van Metre David C. , Wenz John R. , Garry Franklyn B.
Published: February 2023

Lameness remains a major cause of morbidity and economic loss in dairy, cow-calf and feedlot operations. The majority of bovine lameness involves structures of the digit, with digital dermatitis (hairy heel warts), sole ulcers, white line disease, subsolar abscesses and interdigital necrobacillosis (footrot) being among the most common disorders of the digit. Given that owner-initiated diagnosis and treatment appear common in many areas, veterinarians are well positioned to help owners develop protocols for lameness treatment. Application of a few very simple rules of thumb may aid owners in discriminating between cases appropriately managed by farm personnel versus those that warrant prompt veterinary examination. This review will cover guidelines for on-farm diagnosis and treatment of routine lameness cases as well as methods for prompt identification of problematic cases which may require veterinary examination.
Impact of Antimicrobial Use in Animals and Regulatory Response
Authors: Tollefson Linda
Published: February 2023

There is accumulating evidence that the use of antimicrobials in food-producing animals has adverse human health consequences. The use of these drugs in food animals selects for resistant pathogens and resistance genes that may be transferred to humans through the consumption or handling of foods of animal origin. Recent studies have demonstrated that antimicrobial resistance among foodborne bacteria may cause excess cases of illness, prolonged duration of illness, and increased rates of bacteremia, hospitalization and death.

The US Food and Drug Administration (FDA) is committed to resolving the public health impact arising from the use of antimicrobial drugs in food-producing animals. The FDA's goal is to ensure that significant human antimicrobial therapies are not compromised or lost while providing for the safe use of antimicrobials in food animals. The FDA published a guidance document titled "Evaluating the Safety of Antimicrobial New Animal Drugs with Regard to their Microbiological Effects on Bacteria of Human Health Concern" that outlines a pathway drug sponsors can use to address concerns about antimicrobial resistance prior to approval of their drug. 30 The process uses a qualitative risk assessment approach to assess the potential of the intended use of a product to develop resistance in bacteria that may harm humans. The level of risk determines the level of risk management that is required for the drug to be approved.
Effect of Free Stall Pen Design on Feeding Behavior
Authors: Mentink R. L. , Nordlund K. V. , Bennett T. B. , Cook N. B.
Published: February 2023

The purpose of this study was to determine if a difference exists in group feeding behavior in dairy cows housed in free stall pens with either 2-rows or 3-rows of stalls.
Strategies for Shortening the Dry Period
Authors: Grummer Ric R. , Rastani Robin R.
Published: February 2023

The decision to shorten the dry period is dependent on many factors, including milk yield and milk composition during the extra days of milking and into the subsequent lactation, calf survival, incidence of metabolic disorders, reproductive efficiency, and management factors, i.e. facilities and parlor capacity. Shortening the dry period to 30 days may be economically feasible due to only a 5 % loss in milk yield (vs. 60 days dry). However, eliminating the dry period results in a 20-25 % loss in milk yield in the subsequent lactation. Shorter dry periods can facilitate fewer group and diet changes and lead to increased dry matter intake and a more favorable energy balance. These beneficial changes may result in decreased metabolic problems, including reduced liver fat concentrations. Preliminary evidence indicates that reducing dry period length may increase conception rates, which can lead to greater flexibility in breeding programs. However, more replication is needed in field trials to verify potential benefits of short dry periods on reproduction.
Herd-based Testing for Infectious Diseases
Authors: Olson Jerry D.
Published: February 2023

The objective of herd-based testing for specific infectious diseases is to monitor for either the presence of the disease in the herd or the presence of individual animals in the herd with the disease. The information can be used to develop the appropriate control measures to prevent a disease from entering into a herd or to control a disease in the herd by reducing or eliminating the disease from the herd. The herd-based testing is part of the program for control of specific diseases within the herd and needs fit within the goals and objectives of the herd for the overall control of infectious diseases. The needs of herds for herd-based testing and types of herd-based tests used will vary depending upon whether the herd is a "closed-herd," producing its own replacements internally, or purchasing replacement animals from outside sources, whether the herd has had on-going control program and has reduced the prevalence of disease to low levels and needs to now monitor for the presence of the disease. The specific herd-based tests need to be selected based on the goals for the individual herd. For example, the objective of testing for Leptospira hardjobovis is to determine if the disease is present in the herd whereas the objective of tests for BVD may be to identify individual animals that are persistently infected.
Herd-based Testing for Young Stock
Authors: McGuirk Sheila M.
Published: February 2023

Investigation of calf morbidity or mortality problems usually requires an accurate assessment of the colostrum-feeding program as well as documentation of the potential enteric and respiratory pathogens to which the pre-weaned calves have been exposed. The approach to herd-based problem solving and assessment is quite different than testing individual calves. Conclusions and recommendations are based, not just on recent history, impressions, written protocols, examination of affected animals and post-mortem results, but on farm data collection. Accurate conclusions require appropriate sample sizes, discriminating tests and an appropriate population of calves to test. The purpose of this paper is to describe the farm data collection and analysis that determines whether there is a herd problem of failure of passive transfer of immunity (FPT), the level of calf exposure to potential fecal and respiratory pathogens and the determination of antimicrobial susceptibility of potential respiratory pathogens.
Diaphyseal Femoral Fractures in Cattle
Authors: Nichols S. , Anderson D. E. , Hull B. L. , Miesner M.
Published: February 2023

Diaphyseal femoral fractures in cattle often are regarded as unsuitable for treatment. In the past 15 years, several surgical techniques have been described. The age, weight, fracture configuration, intended production use and economic value of the individual influence treatment options. Open reduction and internal fixation may be the treatment of choice in young, lightweight cattle. Medical treatment (stall rest and antiinflammatory drugs) may be an option for older cattle with selected fractures. We hypothesized that diaphyseal fractures in cattle can be successfully managed with proper case selection. The objectives of this study were to evaluate different surgical techniques, to evaluate the risk factors associated with the surgical repair and to evaluate the medical approaches in cases of femoral fractures.
Evaluation of the Use of Cephapirin Sodium Intramammary Therapy in the Closeup Dry Period to Reduce Subclinical Mastitis in Adult Dairy Cattle
Authors: Cole D. , Graves W. , Smith R. , Ensley Doug , Fain J. , Rosenberg J.
Published: February 2023

Subclinical mastitis and milk quality are significant economic issues among dairies. It has been estimated that clinical mastitis can cost $110 per case, and the inclusion oflosses in milk production and discarded milk among subclinically affected cattle increase this estimate to $200. The prevalence of intramammary infections (IMls) peaks in the early and late dry periods, so these times are important to mastitis control programs. This study was designed to examine the potential benefit of intramammary therapy (IMT) administered in the late dry period on the incidence of IMIs in the first 180 days of lactation.
Association between Local (Udder) Clinical Signs and Important Outcomes of Clinical Mastitis Episodes in Dairy Cattle
Authors: Wenz J. R. , Elia R. , Whitman K. , Garry F. B.
Published: February 2023

Clinical mastitis (CM) is the most common infectious disease of dairy cattle and is responsible for significant economic losses. There are many local clinical signs associated with inflammatory changes of the mammary gland during bacterial infection. Treatment and prognosis of CM is often decided based on one or more of these clinical signs, however, there have been no studies evaluating the association of important outcomes associated with CM and the presence of these signs in cows with mild systemic disease.
Cumulative Cure Rates for the Major Pathogens Causing Mastitis
Authors: Lago A. , Gaska J. , Cook N. B.
Published: February 2023

Approaches to clinical mastitis treatment that utilize elements of a cow's history (Lago et al, 2004) and culture information from the affected quarter (Hess et al, 2003), have recently been described. Perhaps an optimal approach to treatment would be obtained by combining these two methods. Pathogen-specific somatic cell count (SCC) patterns before and after clinical mastitis have been documented by De Haas et al (2002). SCC was low before Escherichia coli mastitis cases and cases where bacteria were not isolated, and decreased quickly after a rapid rise. However, SCC was already high before cases associated with Staphylococcus aureus and the streptococci, and remained high afterward. The objective of this paper was to document the distribution of clinical cow cases of mastitis due to different pathogens by SCC status prior to clinical mastitis (Premast SCC) and to analyze Cumulative Cure Rate (CCR) for each of these sub-groups.
Effect of Management Systems on Growth Performance of Buffalo (Bubalus bubalis) Calves in Winter Season
Authors: Poudel R. P. , Gulati H. K. , Yadav R. S.
Published: February 2023

Buffalo (Bubalus bubalis) play an important role as a milk animals in the Indian national economy. India has nearly 57% of the world's buffaloes which contribute 56% of the total milk produced in India, i.e., 86 million tons per annum (FAO 2004). Economic rearing of replacement stock is a prerequisite for successful dairy farming. Buffalo traditionally are considered slow-growing animals, a trait which has a direct effect on early maturity and age of first calving. Low growth rate in young buffalo calves is by far the most important factor contributing to late maturity. The most efficient system of calf-rearing is one that gives higher body weight gain and low cost of feeding. Any management package that can induce early maturity without any detrimental effect on subsequent health of the calf will have a profound economic contribution.
Use of Bulk Tank Milk to Determine the Herd-level Prevalence of N. caninum in Dairy Herds on Prince Edward Island
Authors: Wapenaar W. , Barkema H. W. , Bartels C. J. M. , Van Maanen C.
Published: February 2023

The apicomplexan protozoan parasite Neospora caninum is one of the most frequently diagnosed causes of bovine abortion. Transmission of the parasite occurs vertically from cow to calf with great efficiency, sustaining the infection within cattle herds for many generations. The herd-level prevalence of N. caninum on PEI is estimated to be 20.3%. This is relatively high compared to other Canadian provinces and research is needed to aid in the control of this infection on dairy farms. Serology is the only method available to diagnose N. caninum infection in live animals, but herd surveillance, using serology, is expensive and time consuming, especially in large dairy herds. The use of milk as a diagnostic tool could be very beneficial to the dairy industry, as it would allow for a fast and inexpensive way to test herds for N. caninum exposure. Furthermore, because the majority of dairy herds in PEI collect milk samples monthly (DHI; Dairy Herd Improvement), Neospora surveillance using milk would result in less stress on the lactating cow, and no special visits would be required to collect samples.
Comparison of the Ovsynch Protocol and Exogenous Progesterone with Insemination at an Induced Estrus as Therapeutic Strategies for Ovarian Cysts in Lactating Dairy Cows
Authors: Crane M. B. , Melendez P. , Risco C. A. , De Vries A. , Archbald L. F.
Published: February 2023

It has been suggested that an underlying mechanism in the development of bovine ovarian cysts involves a hypothalamic lesion which causes follicular estrogen to be ineffective in inducing a GnRH/LH surge at the time of estrus. This lesion involves the estrogen receptor alpha (ERa). Furthermore, it has been speculated that treatment with progesterone may induce the ERa in the mediobasal hypothalamus which will foster a GnRH/LH surge in response to follicular estrogen. Collectively, this information suggests that therapeutic strategies for bovine ovarian cysts could involve either the use of GnRH or exogenous progesterone. An intra vaginal progesterone insert (EAZI-BREED™ CIDR®) has been approved for use in lactating dairy cows. The use of a CIDR to synchronize estrus detection is relatively simple and less labor intensive than the OvSynch protocol. Therefore, it could be a more acceptable treatment for ovarian cysts in lactating dairy cows. However, there is no information available concerning the comparative efficacy of these two treatment strategies. The hypothesis of this study was that lactating dairy cows with ovarian cysts treated with exogenous progesterone, a luteolytic dose of PGF2a, and inseminated at an induced-estrus, will have a higher pregnancy rate compared to cows with ovarian cysts subjected to the OvSynch protocol. The purpose of this study was to compare the effectiveness of these two protocols.
Evaluation of Environmental Sampling to Determine Distribution and Dairy Herd Infection Status for Mycobacterium avium subspecies paratuberculosis
Authors: Lombard J. E. , Smith R. L. , Wagner B. A. , McCluskey B. J.
Published: February 2023

An important component of the Voluntary Bovine Johne's Disease Control Program is to determine herd infection status for Mycobacterium avium subspecies paratuberculosis (MAP). To help prevent the transmission of MAP, dairy and beef herds providing replacement cattle should know their infection status. Herds acquiring cattle should be fairly confident that the source herd is at low risk for MAP infection. The current requirements for a herd to be considered Level 1 of the test-negative component requires ELISA testing 30 animals followed by fecal culture confirmation of ELISA-positive cattle. Since the ELISA is approximately 25-50% sensitive, many infected herds are classified as low risk and enter Level 1 based on this testing scheme.
Investigation of Bovine Respiratory Disease Pathogens using Immunohistochemistry Testing on Selected Samples
Authors: Booker C. W. , Janzen E. D. , Clark T. G. , Haines D. , Phil M. , Guichon P. T. , Jim G. K. , Schunicht O. C. , Wildman B. K. , Pittman T. J. , Felton R. K. , Perrett T. , Morley P. S.
Published: February 2023

During the fall of 2004, fall-placed feedlot calves that were diagnosed on gross postmortem examination with bovine respiratory disease (BRD) as the predominant cause of death were pathologically examined in detail using laboratory support to determine the microbiological agents involved in fatal BRD, and to determine if specific microbiological agents were associated with different pathological presentations of fatal BRD.
Building Better Barns
Authors: Weary Daniel M. , Von Keyserlingk Marina A. G.
Published: February 2023

Design and management of the feeding area are important. High stocking densities at the feed bunk increase aggressive competition and keep subordinate cows away from feed. Physical barriers between cows, including head lockers and feed stalls, can help reduce this competition and increase feeding time.

Cows like softer surfaces, for both lying down and for standing upon. Deep-bedded stalls work well for cow comfort, but require maintenance. When it comes to physical structures used to build freestalls, less is more - the hardware we place in the stall is for our benefit, and not the cow's. The more restrictive we design stalls, the less attractive they become for the cow. Use of restrictive stall designs can help keep stalls clean, but to avoid problems with hoof health these designs need to be accompanied by better flooring options, such as softer and drier flooring.
Ovarian Responses to Treatment of Non-Lactating Cycling Holstein Cows with a Combination of Progesterone and Either GnRH or Oestradiol Benzoate, Injected at Diestrus
Authors: Segwagwe B. V. E. , Macmillan K. L. , Mansell P. D.
Published: February 2023

Treatment of cycling cows with GnRH or ODB at the time of CIDR device insertion during diestrus (day 13) caused follicular turnover and a synchronized emergence of a new follicular wave. Thisfollicular wave emerged earlier in GnRH than in ODBtreated cows. Following the synchronized emergence of a new wave, there was a synchronized onset of estrus and ovulation. The onset of estrus and ovulation were not influenced by treatment. ODB caused atresia of every second dominant follicle, while GnRH could not consistently ovulate this second dominant follicle. The inability of GnRH to consistently cause follicular turnover may be a limitation to its use.
Preliminary Investigation on Identification of Lame Dairy Cattle Using Pedometer Measures
Authors: Mowrer M. E. , Epperson W. B.
Published: February 2023

Use of the commercial activity monitor described here had a limited ability to accurately diagnose lameness in this herd.
Update on Leptospira hardjo-bovis Control in Beef Herds
Authors: Wikse Steven E.
Published: February 2023

Leptospira hardjo bovis has emerged as the most common leptospiral infection of cattle in the United States and Canada. Its new name is Leptospira borgpetersenii serovar Hardjo (hardjo bovis), referred to as 'hardjo-bovis'. The main reason for the widespread prevalence of hardjo-bovis is that it is very efficiently transmitted by a chronic renal carrier/shedder state lasting a year or more. Also, traditionaJ 5-way leptospira vaccines have provided poor protection against hardjobovis because they contain a different hardjo organism, L. hardjo prajitno, which is not found in North America.

Experimental and natural infections of cattle with hardjo-bovis result in reproductive losses including embryonic death, abortion, stillbirths and weak calves. In addition, involvement of the mammary glands in hardjobovis infections can result in the "mastitis/flabby bag syndrome" of beef cattle. In the field, it has been extremely difficult to diagnose hardjo-bovis because traditional use of serology to diagnose leptospiral infections works very poorly for diagnosis of hardjo-bovis. As the maintenance host for hardjo-bovis, cattle mount a weak and transitory antibody response to infection. Identification of leptospires in urine correlated with antibody titers to hardjo-bovis and several other serovars of leptospira can overcome that obstacle to diagnosis. The combination of losses typically not noticed by ranchers, such as embryonic deaths, and the difficulties in diagnosing hardjo-bovis as the cause of obvious losses like abortions have made hardjo-bovis a "hidden disease".

Programs to control hardjo-bovis in beef herds are now possible because of the identification of two antibiotics that can clear the renal carrier state of hardjo-bovis and the availability of new leptospira vaccines that contain hardjo-bovis. Hardjo-bovis control programs have four parts: 1) enhancement of general herd resistance; 2) biosecurity; 3) antibiotic treatment to eliminate the renal carrier state; and 4) vaccination. The primary consideration in the decision on whether to implement a control program for hardjo-bovis in a beef herd is how great is the disease threat?

There are still gaps in our understanding of hardjo-bovis infection of beef herds. Diagnostic testing is still cumbersome. Hardjo-bovis-specific polymerase chain reaction (PCR) tests now being perfected will make possible accurate, fast diagnoses of hardjobovis in urine or tissue samples. That will greatly aid in identification of problem herds and in monitoring the success of control programs. Like most infectious diseases of cattle, clinical trials are needed in United States beef cow/calf operations to determine the herd-level economic impact of hardjo-bovis infection and efficacy of control programs.
Economic, Reproductive, and Performance Effects of PI BVD in Commercial Cattle Operations
Authors: Larson Robert L.
Published: February 2023

Bovine viral diarrhea virus (BVDV) infection can cause a range of reproductive, performance, and health problems in commercial cow herds. The primary reservoir of BVDV is cattle persistently infected (PI) with the virus, and BVDV is most commonly introduced into a herd through contact with a PI animal. The economic loss in a given herd varies due to factors such as herd immunity and the timing of PI introduction into the herd. Losses due to BVDV are minimized by initiating a biocontrol strategy that includes testing for PI cattle and vaccinating to enhance herd immunity.
Feedlot Lameness
Authors: Griffin Dee
Published: February 2023

Lameness affects approximately one of every six cattle in feedlots and accounts for 70% of all sales of non-performing cattle. Salvaged lame feedlot cattle only recover half of their original purchase price, and on average have approximately three month production costs included in their expense before salvage. This paper outlines prevention, treatment and management considerations for the more common causes of feedlot lameness.
Update on Parasite Control in Small Ruminants 2006
Authors: Kaplan Ray M.
Published: February 2023

Gastrointestinal nematode (GIN) parasites are the single most important health problem of sheep and goats. Traditionally, parasites have been controlled by frequent administration of anthelmintic drugs. However, the emergence of multiple-drug resistant parasites now threatens this paradigm of control and new approaches are required.

Anthelmintics can no longer be thought of as an inexpensive management tool to be used as needed to maximize animal productivity. Instead anthelmintics must be thought of as extremely valuable and limited resources that should be used prudently. In response to this changing paradigm of anthelmintic use, new recommendations for parasite control have been proposed. The basis of this approach is to use the knowledge we have about the parasite, the animal, and the drugs to develop strategies that maximize the effectiveness of treatments while also decreasing the development of drug resistance. The term "Smart Drenching'' is often used to describe this approach to worm control. Due to the complexities ofinstituting such a program, successful implementation will only be possible with the help and active involvement of small ruminant veterinarians and other animal health professionals. Additionally, new innovative schemes using novel and sustainable approaches must be implemented. There are a number of new non-chemical technologies that will become increasingly important in GIN control programs both in the short and long term future. However, it is highly likely that any new technologies or developments in non-chemical GIN control methods will be less effective than chemical control has been (prior to emergence of drug resistant parasites). Therefore, as novel non-chemical control modalities become available and widely applied, anthelmintics will still be required for life-saving therapy when control fails. Unless veterinarians take an active and leading role in the education of small ruminant owners and help to implement these new approaches to parasite control, there may be no effective anthelmintics remaining when that time comes.
Therapy of Diarrhea in Calves
Authors: Wagner Sarah
Published: February 2023

Diarrhea in calves can result in physiological derangements including dehydration, acidosis, hypothermia, septicemia and infection, systemically or elsewhere. A thorough physical examination of calves presented with diarrhea will help to determine which problems are present. Therapeutic options include include oral or intravenous administration of fluids containing electrolytes, energy sources and/or alkalinizing agents, warming the calf, antimicrobial drugs, and changes in feeding management.
Case Report
Authors: Currin J. F. , Blodgett D. J. , Rudolph J. S. M.
Published: February 2023

A catastrophic toxicology case involving a well managed herd of 168 beef cows is reported. During the course of this case several rule-outs were considered, and many diagnositc tests were run.
Correlation between Visual Locomotion Scoring System and an Electronic Locomotion Scoring System
Authors: Bicalho R. C. , Cheong S. H. , Warnick L. D. , Guard C. L.
Published: February 2023

Detection of lameness is a bottleneck on many dairy farms. Large dairy farms set goals to decrease the costs of labor. Lameness economic losses can be amplified by delayed detection and treatment. An accurate electronic lameness detection system could minimize losses caused by lameness. The objective of this study was to evaluate the correlation of a visual locomotion scoring system and an electronic scoring system (stepmetrix).
Survival of Commercial Dairy Cows after Digit Amputation or Arthrodesis Surgery
Authors: Bicalho R. C. , Cheong S. H. , Warnick L. D. , Nydam D. V. , Guard C. L.
Published: February 2023

Common digit diseases, such as sole ulcers, sole abscesses, foot rot and white line disease may become complicated by extensive corium and laminae tissue necrosis, leading to deep sepsis of the digit. Septic arthritis of the distal interphalangeal (DIP) joint constitutes 3 to 10% of all hoof conditions. Deep infection of the digit causes severe lameness and, in herds with high incidence oflameness, economic losses from this condition may be significant. Digit amputation is the standard treatment for deep sepsis of the bovine foot in the field. It is reported that cows that had digit amputation were retained in the herd for an average of 13 months, while cows that had arthrodesis surgery were retained for an average of 18 months. However, there were no control cows in those studies with which to compare the survival time. The objective of this study was to evaluate the effect of digit amputation and arthrodesis surgery on survival.
Economic Model That Assesses Costs and Impacts for Dairy Producers as a Consequence of Variable Antibiotic Treatment Compliance
Authors: Galligan D. , Saltman R. , Basse G. , Sorensen S. , Baker T. , Hollenbeak C.
Published: February 2023

The economic impact of partial or noncompliance to antibiotic medications for infections in dairy cattle has not been well studied. In humans, there are multiple published economic models that analyze the impact of treatment compliance with antibiotic effectiveness and resolution of patient symptoms. In cattle medicine, antibiotic agents with reduced-dosing regimes have become available that may result in better compliance relative to older agents. A decision analytic model was developed to examine the costs and consequences associated with antibiotic compliance across various antibiotic regimens from the perspective of the dairy producer.
Experimental Acute BVDV Infection in White Tail Deer Fawn
Authors: Ridpath J. F. , Mark C. S. , Chase C. C. L. , Neill J. D.
Published: February 2023

Bovine viral diarrhea viruses (BVDV) infect a number of domestic and wildlife species besides cattle. Because free ranging cervid populations are frequently in contact with domestic cattle in the US, possible transfer of BVDV between cattle and cervids has significant implications for proposed BVDV control programs. BVDV has been isolated from German roe deer, Scottish deer, white tail deer and mousedeer, but little information is available regarding clinical presentation and progression of infection in these species. Preliminary studies of experimental infection of deer with BVDV have noted seroconversion but no clinical signs. In this study we infected white tail deer fawns, negative for BVDV and antibodies against BVDV, with either a type 1 or a type 2 BVDV The clinical progression following inoculation in these fawns was similar to that seen in BVDV infections in cattle and included fever and depletion of circulating lymphocytes.
Investigation of the Role of Bovine Viral Diarrhea Virus (BVDV) in Undifferentiated Fever of Feedlot Cattle
Authors: Guichon P. T. , Haines D. , Jim G. K. , Booker C. W. , Schunicht O. C. , Wildman B. K. , Pittman T. J. , Perrett T. , Morley P. S. , Ellis J. , Appleyard G. , West K.
Published: February 2023

The undifferentiated fever (UF)/bovine respiratory disease (BRD) complex continues to be the single most important infectious disease entity in beef feedlot production. Current management practices have focused on successfully managing this disease complex through the use of prophylactic and therapeutic antimicrobial strategies, as well as vaccination programs targeting common viral and bacterial etiologic agents of feedlot UF/BRD described in the veterinary literature. In spite of these preventive and control strategies, there are substantial amounts of concrete and circumstantial epidemiologic, pathologic, serologic, and immunologic evidence that BVDV infection continues to play an important role in UF/BRD in commercial feedlot production, even though BVDV vaccination programs are in use.

The purpose of the project reported herein was to improve our understanding of the role that BVDV plays in the pathogenesis of pen-level UF/BRD. The specific objectives of this study were: to describe the frequency and character (Type I or Type II) of BVDV infections both persistent infection (PI) and acute infection (AI)) at feedlot arrival and at the time of initial UF diagnosis; to investigate the effects of BVDV PI animals on pen-level animal health and feedlot performance; to investigate the effect of BVDV viremia on subsequent animal health outcome; and to describe the frequency of BVDV identification in postmortem tissue samples using immunohistochemistry.