bluuebunny/crossref_metadata_2025 huggingface dataset:
Selection and Management of Natural Service Sires in Dairy Herds
Authors: Overton Michael W. , Risco Carlos , Dalton Joseph C.
Published: February 2023

Dairymen and veterinary consultants alike should be aware of the unique management factors associated with use of bulls in dairies as compared to beef herds, as well as the additional safety concerns. Management factors that should be considered when using bulls in dairies include the high calcium, high energy and relatively lower fiber rations of lactating dairy cows, the use of potentially high risk by-product feed ingredients such as cottonseed, and the potentially harmful effects of confinement housing and concrete on estrus detection and service rate. Other considerations are general health, difference in average age of bulls being used as compared to beef herds, and the resulting issues regarding libido, and the potentially high risk of turnover in service sires as a result of the combination of these factors. The objective of this paper is to provide veterinarians with information to help dairy producers improve the management of their natural service sire programs. While this paper doesn’t discuss the specific economic costs associated with use of natural service sires, it does offer suggestions to improve the efficiency of their use.
Implementing and Managing Reproduction Programs
Authors: Day John D. , Kral Jannell
Published: February 2023

There are a number of programs available to help in the implementation of new technologies. These utilize standardized management processes to identify potential problems before they occur. The desired critical control point management is accomplished through a combination of team building, employee education, proactive listening, and process analysis. The team meetings result in standard operating procedures and monitoring processes that are implemented to achieve management goals.
Prevalence and Risk Factors of Pathogenic E. coli, including 0157:H7, in Western Canadian Cow-Calf Herds
Authors: Gow Sheryl , Waldner Cheryl , Ngeleka Musangu
Published: February 2023

There is increasing concern about the potential impact of intensive livestock operations on the environment and the risk that they potentially pose to human health. The purpose of this project was to identify the prevalence of pathogenic Escherichia coli in calves at calving and the risk factors associated with infection.
Reproductive Performance Following Timed Artificial Insemination in Silage-fed Beef Cows
Authors: Wichtel Jeff , Charmley Ed , Richardson Gavin , Lofstedt Rob
Published: February 2023

Many studies have examined methods for estrous synchrony in beef cows, yet very little controlled research has addressed the interaction between postpartum energy intake and synchrony system. The objectives of this study were to compare the effectiveness of two estrous synchronization methods (Ovsyilch or CIDR®) for use in timed artificial insemination (TAI) programs in silage-fed beef cows, and to examine interactions between synchronization method and postpartum energy intake.
Relative Comparison of Diagnostic Tests for Johne's Disease
Authors: Hendrick S. , Duffield T. , Kelton D. , Leslie K. , Lissemore K. , Archambault M.
Published: February 2023

Prevention and control of Johne's disease would be much improved if diagnostic tests were able to reliably determine the infection status of subclinically infected cows both rapidly and economically. Serology-based tests offer the convenience of quick diagnosis at a low cost, but their precision and accuracy remain questionable. The objective of this study is to evaluate a commercially available milk ELISA test relative to other diagnostic tests, and determine if it offers any improved test characteristics.
Comparison of Two Techniques for Laparoscopic Abomasopexy for Correction of Left Displaced Abomasum in Dairy Cows
Authors: Newman K. D. , Anderson D. E.
Published: February 2023

Laparoscopic abomasopexy has been described to reduce the incidence of complications associated with traditional laparotomy and the blind, roll-and-tack corrective techniques for left-displaced abomasum in cattle. As originally described, this surgical technique involved left paralumbar fossa laparoscopy in standing cattle for placement of the abomasopexy suture, followed by right paramedian laparoscopy for suture retrieval. We hypothesized that laparoscopic abomasopexy could be performed successfully in cattle through a right paramedian laparoscopy alone. The purpose of this study was to compare the "two-step" procedure to a "one-step" procedure for laparoscopic abomasopexy.
High Prevalence of Subclinical and Clinical Mastitis Caused by Environmental and Minor Pathogens in a Large Dairy Herd in Iran
Authors: Bolourchi M. , Kasravi R. , Hovareshti P. , Farzaneh N.
Published: February 2023

Environmental and minor pathogens seem to be of increasing significance, especially in situations where major contagious pathogens (Streptococcus agalactiae and Staphylococcus aureus) have been controlled using post-milking teat disinfection and dry cow therapy. Herd management practices that successfully control contagious pathogens fail to control coliforms and many streptococcal bacteria. Coagulase-negative staphylococci (CNS) are the most prevalent bacteria isolated in herds using currently recommended control measures and Corynebacterium bovis ( C. bovis) was identified as the cause of up to 20% of all cases of clinical mastitis in some herds.
Exotic Disease Threats
Authors: Torres Alfonso
Published: February 2023

The term "exotic disease" or "foreign animal diseases" (or FADs) is used to group more than fifty animal diseases that are not currently in the US. Thirteen of them have been eradicated from our country after intensive, expensive and long duration campaigns. Many of these diseases are important zoonotic diseases.

This presentation will review thirteen exotic diseases that affect cattle, grouped into three categories:1. Highly contagious diseases.2. Non-highly contagious diseases.3. Vector-borne and parasitic diseases

The following information will be summarized for each disease: definition, etiology, global epidemiology, clinical signs and lesions.
Breeding Soundness Evaluation
Authors: Warner Gary D.
Published: February 2023

The bull breeding soundness evaluation (BSE) should be an integral part of any herd health management program to maintain and promote herd profitability and health. Physical examination of the bull is a very important aspect of the overall evaluation, and should be given careful consideration by the practitioner. The bull must be fit and in condition to properly identify and service the cows presented to him. It is the veterinarian's responsibility to evaluate body condition, foot and leg structure, reproductive system, temperament and quality. Other considerations, such as breed selection, evaluation of expected progeny differences (EPD), ultrasound data evaluation and feed trial performance may be requested of the veterinarian.

Proper equipment to conduct the evaluation and facilities for restraint of the bull are important. Mature bulls, particularly those of questionable disposition, require substantial facilities for evaluation. Selection and maintenance of the proper equipment is of major importance to the success of the examination. Malfunctioning equipment or lack of adequate restraint can seriously limit the veterinarian's ability to properly collect and evaluate a semen sample. A proper and complete exam can be of direct benefit to the owner, whether it be the consequence of a sale or a part of an annual exam before the breeding season. It should be considered as an insurance policy against the financial loss of a failed breeding season.
Near Infrared Spectroscopy as a Potential Method to Detect Bovine Respiratory Disease
Authors: Fox J. T. , Spire M. F.
Published: February 2023

Bovine respiratory disease (BRD) continues to bethe leading cause of illness and death loss from weaning through finishing. There is no objective method to evaluate a live animal's severity of sickness or their response to treatment. A pilot study was conducted at a commercial feedyard to evaluate the ability of near-infrared spectroscopy to differentiate between cattle identified as healthy and those identified as having undifferentiated bovine respiratory disease. At processing, 215 randomly selected 900 lb (409 kg) heifers were evaluated to determine tissue oxygen saturation (StO2) levels. Mean ranks of the StO2 values were found to be 176.86+/- 5.50. One-hundred head of cattle pulled for clinical signs of bovine respiratory disease were evaluated in the hospital. Animals were classified as first pull, second pull and third pull based upon clinical observations. First pull animals were those with no previous history of being treated for respiratory disease and having signs of BRD with rectal temperature at or above 104 ° F ( 40° C). Second pulls and third pulls were those animals failing to respond to either a first treatment or a second treatment for BRD as evidenced by no improvement in clinical appearance or rectal temperature remaining above 104.0 F. Mean StO2 ranks were 110.42 +/- 11.29, 120.08 +/- 14.48 and 132.83 +/- 19.00 for first, second and third pulls, respectively. A significant difference was found between the rank of the StO2 values in cattle at processing and those classified as first, second or third pulls (P<0.05). No difference was found between the three pull classifications. The authors feel that the results shown in this study provide the basis for further research in the evaluation of BRD with near-infrared spectroscopy.
Study to Compare the Efficacy of Three Oxytetracycline Regimens for the Treatment of Anaplasma Marginale Carrier Status in Beef Cattle
Authors: Coetzee J. F. , Apley M. D. , Kocan K. M. , Knowles D. P. , Donkersgoed J. V.
Published: February 2023

Anaplasmosis is a blood-borne disease of cattle and other ruminants caused by Anaplasma marginale. Animals recovering from clinical anaplasmosis and those treated with therapeutic doses of oxytetracycline remain persistently infected with microscopically undetectable levels of the organism. These animals serve as reservoirs of the disease which can be spread mechanically or through arthropod vectors. Tetracyclines are the only compounds approved for treatment of acute anaplasmosis infections in the United States; however no compounds are approved for eliminating the carrier state. This has contributed to the restricted movement of cattle from endemic areas of the US to anaplasmosis-free territories such as Canada. Anaplasmosis is estimated to cost the US cattle industry $100 million per year, with some estimating the cost of resticted trade to be near $300 million annually. The objective of this study was to compare the effects of three oxytetracycline treatment regimens on eliminating Anaplasma marginale infection from carrier beef steers.
Comparison of J-5 Vaccinates and Controls for Clinical Severity, Milk Production Change, Etiologic Agent, and Survival in the Herd Following Naturally Occurring Cases of Clinical Mastitis
Authors: Wilson D. J. , Mallard B. A. , Burton J. L. , Grohn Y. T. , Schat K. A. , Schukken Y. H.
Published: February 2023

Naturally occurring cases of clinical mastitis (CM) were studied among J-5 vaccinates or controls on three commercial dairy farms. Measures of clinical severity, milk production change and survival in the herd were evaluated for differences between the two groups. Particularly the study looked at protection against being culled with mastitis as the primary reason, including time-to-event analysis.
Single Subcutaneous Dose of a Combination Vaccine Containing Bovine Herpes Virus- 1 (BHV-1) Provides Protection Against an Intranasal BHV-1 Challenge 72 Hours Later
Authors: Fogarty-Fairbanks K. K. , Campbell J. , Chase C. L.
Published: February 2023

Bovine herpesvirus 1 (BHV-1) is associated with several disease syndromes in cattle. The BHV-1 respiratory infections can result in several clinical manifestations that range from inapparent to severe respiratory disease, infectious bovine rhinotracheitis (IBR). Signs include pyrexia, anorexia, conjunctivitis with lacrimal discharge, dyspnea and nasal discharge. BHV-1 respiratory infection in calves and feedlot cattle can lead to the bovine respiratory disease complex (BRDC), with secondary bacterial infections that cause significant economic losses to the livestock industry.

Vaccination programs are a routine practice in US feedlot operations to protect cattle against BHV-1 associated disease. Unfortunately, many calves are not vaccinated prior to weaning or commingling into backgrounding lots, feedlots or pasture operations. These animals are at increased risk of BHV-1 infection and are predisposed to secondary bacterial pneumonia. The time from vaccination to onset of protection can play an important role in subsequent management of newly arrived cattle against IBR.

An experiment was conducted to determine the onset of protection against an intranasal BHV-1 challenge following a subcutaneous injection of a commercial modified-live virus (MLV) vaccine containing attenuated BHV-1.
Effect of Milk Urea Nitrogen and Nutrition on Reproductive Performance in Commercial Dairy Herds in Prince Edward Island, Canada
Authors: Arunvipas P. , VanLeeuwen J. A. , Dohoo I. R. , Keefe G. P. , Burton S. A. , Lissemore K. D. , Leger E. R.
Published: February 2023

The objective of this study was to investigate the impact of nutritional and management factors and milk urea nitrogen levels on reproductive performance in a large number of commercial dairy herds in Prince Edward Island (PEI), Canada.
Preliminary Study to Evaluate the Feasibility of Chemical Ablation of the Seminal Vesicles in the Bull
Authors: Waguespack R. W. , Schumacher J. , Wolfe D. F. , Sartin E. A. , Heath A.
Published: February 2023

Bulls affected with septic seminal vesiculitis are often classified as unsatisfactory potential breeders due to leukocyte contamination, poor sperm motility and other abnormalities noted during the breeding soundness examination.1,2 The prognosis of chronically affected bulls for resolution of this condition using antimicrobial therapy, sclerosing agents or surgical removal is guarded at best.1,2,5 Because of this poor response to present treatment options, we performed a preliminary study investigating a method of chemically ablating the entire seminal vesicle with a 4% formaldehyde solution. In horses, ablation of ethmoidal hematomas and salivary glands using a 4% formaldehyde solution is successfully documented.3,4 The goal of this study was to determine the feasibility of injecting the seminal vesicles of healthy bulls, percutaneously, with a 4% solution of formaldehyde, and the efficacy of this procedure in ablating the parenchyma of the seminal vesicles as a potential treatment of chronic septic seminal vesiculitis.
Variation of Virulence Factors Associated with Clostridium Perfringens Type A in Cattle
Authors: Porter M. C. , Simonson R.
Published: February 2023

Clostridium perfringens Type A is implicated in several cattle diseases including abomasal ulcers and tympany, gas gangrene and possibly jejunal hemorrhage syndrome. Recently, there has been an increased incidence of enteric disease case reporting due to this organism. Pathogenesis of disease includes colonization and production of large amounts of alpha toxin. In addition, debate continues to surface concerning the alleged role of beta2 toxin in bovine disease. Until there is conclusive evidence that beta2 is not involved in pathogenesis, it cannot be ignored in preventative strategies or vaccine technology. The increased prevalence of this organism and the range of disease severity led to the examination of toxin production and growth variation between strains.
Present and Future Control of Cryptosporidiosis in Cattle
Authors: Nydam Daryl , Peregrine Andrew S.
Published: February 2023

Cryptosporidiosis continues to be a problem for dairy calves and a perplexing public health risk, despite recent advances in molecular biology that have contributed to our knowledge of the pathobiology of the causative organism. Cryptosporidium infects at least 155 mammals, including humans and dairy cattle, primarily resulting in diarrhea. Unfortunately, the somewhat unique lifecycle of this protozoan and the armor of its oocysts leaves us little defense. This paper reviews aspects of transmission, disinfection, treatment, prophylaxis, nomenclature, and zoonotic concerns of cryptosporidium.
Siderophore Receptor and Porin Protein Technology for Control of Salmonella and Escherichia coli 0157:H7 in Cattle
Authors: Stevens E. T. , Thomson D. U.
Published: February 2023

Siderophore receptor and porin protein vaccine technology is a new tool to control clinical and subclinical bacterial disease in cattle through protection of exposed animals and decreased shedding in animals with enteric bacterial colonization. Data in this review have shown that the immune system of animals normally doesn't recognize SRP proteins. However, if primed the immune system will continue to increase the titer against these proteins without re-vaccination. These novel subunit Escherichia coli and salmonella vaccines have shown to decrease mortality and condemnation while increasing the performance in fed turkeys. The salmonella and E. coli 0157:H7 vaccines have shown to prevent mortality and decrease shedding of both salmonella and E. coli 0157:H7 in mice and cattle. The decrease in shedding and protection from subsequent disease leads to increased production, as illustrated by the results in dairy cow studies. After effectively demonstrating control of salmonella and E. coli, it is exciting to think of the potential that SRP vaccine technology has for control of numerous bacterial disease complexes in cattle such as bovine respiratory disease complex (BRDC), liver abscesses, footrot and pink eye.
Effects of Growth Hormone Releasing Hormone Delivered by Plasmid Injection and Electroporation on the Immune Function and Body Condition Scores in Holstein Heifers
Authors: Brown Patricia A. , Davis William C. , Draghia-Akli Ruxandra
Published: February 2023

Novel DNA-based technologies were recently introduced for various purposes, including to direct the in vivo production of hormones and other peptides for therapeutic or preventative applications. Growth hormone releasing hormone (GHRH) is a hypothalamic hormone with both direct and indirect effects on the maintenance of health and immune status under an array of conditions. Our previous studies have shown that delivery of optimized plasmids by intramuscular injection followed by electroporation is scalable and represents a promising approach for long-term stable production of GHRH in pigs and dogs. We have now tested this approach to optimize GHRH levels in Holstein heifers, and characterized the effects of the therapy on the immune and health status of the treated subjects and controls.
Production Effects of Mycobacterium avium subspecies paratuberculosis Infection Based on Diagnostic Test Results
Authors: Lombard J. E. , Wagner B. A , McCluskey B. J. , Garry F. B.
Published: February 2023

Several studies have evaluated the production effects of Mycobacterium avium subspecies paratuberculosis (MAP) infection with various outcomes. Some studies have reported up to an 18% reduction in milk production for fecal-culture-positive cows compared to fecal-culture-negative cows. A4% reduction in milk production was observed in serum-ELISA-positive cows compared to test-negative cows in one study, while other studies have reported no differences between test-negative and test-positive cows. Most of these studies were restricted to a small region of the US and a relatively small number of operations.
Uterine Bacterial Isolates and Reproductive Performance in Lactating Holstein Cows with Uterine Health Disorders, Large Calves and Fever
Authors: Hammon Doug , Johnson Heidi , Wareham Cory , Stott Rusty
Published: February 2023

Uterine health disorders are common in dairy cows and result in reproductive inefficiency and economic loss in dairy herds. Specific uterine bacteria associated with some uterine health disorders have been described. However, information regarding the relationship between calf birth weight and uterine bacteria is lacking. The aim of this study was to evaluate relationships between uterine bacterial isolates during the first four weeks after calving, uterine health disorders (metritis, retained placenta [RP], clinical and subclinical endometritis), fever and calf birth weight. The impact of uterine health disorders on reproductive performance was also evaluated.
Effect of Different Prostaglandin Treatment Protocols on Luteolysis and Ovulation in Dairy Cows
Authors: Szenci O. , Répási A. , Sulon J. , Reiczigel J. , Beckers J. F.
Published: February 2023

During the past 25 years, several methods were developed to synchronize estrus in dairy cattle. Synchronization with prostaglandin F2α (PGF2α) is successful when cows are bred at a detected estrus because estrus detection rates and artificial insemination (Al) are more efficient than daily detection of estrus (Stevenson and Pursley, 1994). The success of estrous induction with PGF2α depends on the presence of a functional corpus luteum (CL). In case of a palpable CL, Archbald et al (1994) found that the percentage of milking cows observed in estrus within seven days after treatment (25 mg of PGF2α) was 55% (61/111). This management tool still does not control the time of AI, because estrus detection continues to be necessary, which is evidenced by the lower pregnancy rate after timed AI compared with AI after detected estrus. This might be partially explained by the variation in time of ovulation over periods of five days with respect to time of AI (Stevenson et al, 1987). Various attempts have been made to overcome this variability in response to PGF2α treatments. The administration of other hormones in conjunction with PGF2α, such as progesterone, estradiol benzoate, human chorionic gonadotropin (hCG) and gonadotropin releasing hormone (GnRH) (Deletang 1975; De Rensis and Peter 1999; Pursley et al, 1996), have been attempted. There was a better degree of synchronization but the pregnancy rate was similar to that of untreated cows. Similarly, two prostaglandin injections at an eight-hour interval was more effective on the incidence of luteolysis than a single injection (Archbald et al, 1993). There are several studies dealing with the effect of prostaglandin on the area changes of corpus luteum and follicles in heifers (Kastellic and Ginther 1991), on corpus luteum size and plasma progesterone concentrations in cattle (Assey et al, 1993), and the effect of different doses of PGF2α on fertility (Lagar 1977), however the effect of different doses of PGF2α on the area changes of the corpus luteum, the largest follicle and the progesterone (P4) concentration has not been examined. The objective of our study was to compare the effect of different doses of PGF2α (first trial-0 mg, 25 mg, 35 mg; second trial-2 x PGF2α treatment at an eight-hour interval) on the corpus luteum, the largest follicle and the progesterone concentration in dairy cattle. The time to ovulation after AI in PGF2α-treated and untreated cows (third trial) was also determined.
Factors Associated with ELISA Sample/Positive Ratio Scores for Paratuberculosis in an Angus-Brahman Multibreed Herd of Beef Cattle
Authors: Elzo M. A. , Rae D. O. , Lanhart S. , Wasdin J. , Dixon P. , Jones J.
Published: February 2023

Paratuberculosis is a chronic disease of ruminants that causes economic losses in beef and dairy cattle due to diminished production and eventually death. Dam and calf genetic and environmental factors were evaluated for their association with enzyme-linked immunosorbent assay (ELISA) sample to positive ratio scores for paratuberculosis in a multibreed beef cattle population.
Research Summaries - French Translations
Authors: Vinet Louise , Beauchamp Guy , Brochard Hubert , Smith Pierre-Paul , Bovine Practitioners American Association of
Published: February 2023

Comptes Rendus de Recherche 1-4
Establishing and Managing an In-House Mastitis Lab
Authors: Mills Bradley W.
Published: February 2023

Milk culture is another mastitis detection tool that has been used for numerous years in udder health management. It is usually considered the gold standard for diagnosing subclinical and clinical intramammary infections in dairy cattle. Private veterinarians should seriously consider setting up a milk microbiology laboratory in their practice for the benefit to the clients, the diversification of their services and the economic return to their practice.
Influence of Using Fan and Sprinkler Cooling Systems on Physiological Responses of Heat-Stressed Holstein Cows
Authors: Baei S. F. Rezazadeh
Published: February 2023

Lactating dairy cattle produce large amounts of heat due to digestion and metabolic processes; this heat must be exchanged with the environment to maintain normal body temperature.

The Temperature Humidity Index (THI) could be used to evaluate thermal stress caused by the environment. This index combines relative humidity (RH) and ambient temperature (Ta) into a single value to estimate the potential environmental heat load. An environment is generally considered stressful for cattle when the THI exceeds 72. Sprinkling and supplemental airflow -to-reduce heat stress (HS) has been evaluated in many studies.

Thirty Holstein dairy cows were used in this study to evaluate the effect of three different cooling systems on physiological responses, including rectal temperature (RT), respiration (RR) and heart rate (HR), during August and September, with daily average Ta between 73 and 86°F (23 and 30°C) and Rh between 67 and 91 % at Sari City, Northern Iran.

Control cows had access to six fans (C). A second group was cooled with twelve fans (F), and the third group of cows was cooled with twelve fans and sprinklers (F/S). The maximum THI during the trial ranged from 73.1 to 99.7 (83.63 ± 3.333).

Ta, and as a result THI, were less (P<0.05) in F/S (77.8 ± 6.58°F and 74.9 ± 5.62) and F (82.4 ± 7.44°F and 78.8 ± 6.44) groups compared to the C group (83. 7 ± 7. 71 °F and 79.9 ± 6.64).

The average of RT (103.1 ± l.02°F; 39.5 ± 0.566°C), RR (79.2 ± 10.2 breaths/min) and HR (79.4 ± 4.32 beats/ min) of cows in the C group were higher (P < 0.05) than those in the F (102.6 ± 0.96°F [39.2 ± 0.638°C], 67.7 ± 12.8 and 77.3 ± 3.98) and S/F (101.7 ± 0.94°F [38.7 ± 0.521°C], 55.1 ± 12.7 and 76.7 ± 4.60) groups, respectively.

These results indicate that a cooling system based on spray and fans is an effective alternative to alleviate the negative effects of HS on physiological responses in lactating Holstein cows under warm and humid conditions.
Growing Your Cattle Practice by Building "Management-Partner" Relationships
Authors: Groves John T.
Published: February 2023

Veterinary practitioners serving beef producers are faced with the challenge of providing expert services in an environment where many veterinarians have opted out of agriculturally-based practices, leaving an increased demand for services. In an effort to adapt to a rapidly changing beef industry, some practitioners have fundamentally changed the way they practice. This paper describes the changes made in my rural Missouri practice that have helped me develop a thriving practice based on serving beef producers' needs.
Field Trial of Vaccination against Leptospira borgpetersenii serovar hardjo bovis in a Single New York Dairy Herd
Authors: Guard C. L. , Nydam D. V. , Eicker S. W.
Published: February 2023

Dry cows and late gestation heifers were assigned randomly to receive a monovalent vaccine against L. borgpetersenii serovar hardjo-bovis at about 220 days of gestation or nothing. A second dose of vaccine was administered about 28 days later to the vaccinated group. Before the trial, the herd was determined to be infected. Five of 45 lactating animals chosen by convenience were shedding leptospires in urine by fluorescent antibody testing. The herd was milking about 2600 cows during the duration of the trial. There were 1208 animals enrolled in the trial, 601 controls and 607 vaccinates. The reproductive management of the herd was not changed during the study period. Outcome measures were first service conception rate: 27% for controls, and 36% for vaccinates, chi square test, p=0.004. Survival analysis of days to conception: 50% were pregnant at 105 days in controls, and 90 days in the vaccinated group, Wilcoxon rank sum of Kaplan Meir estimates p<.001. Overall pregnancy rate from DC305 for controls was 19%, and 21 % for vaccinates. There were nearly equal abortions after first pregnancy palpation at 35-41 days after breeding, 56 in the control group and 58 in the vaccinates. Vaccination in this herd improved reproductive performance by increasing the apparent conception risk to first service.
Animal Welfare Audits
Authors: Reynolds Jim
Published: February 2023

Consumers of dairy products look to veterinarians and producers to ensure humane care is provided to farm animals. Animal welfare is a consensus of opinions, and what is considered acceptable welfare, or husbandry, changes over time. Animal welfare can be assessed or described in three different approaches: animal bodies (physiologic, production, disease), animal natures (comparison to similar animals in nature) and animal minds (feelings, suffering).

All three approaches should be considered when judging animal welfare. Audits are structured events so they can be repeatable and defendable. Auditors should have education in the given species and experience in the industry to evaluate different housing and management systems. The goal of an auditor is not to pass or fail the farm, but to determine if the agreed-on processes are being carried out. The auditor is verifying the welfare of the animals to consumers and retailers and is neutral to the farm. Training for auditors covers the welfare issues of the species, some industry standards, and how to perform an audit and comply with that company's requirements. The Professional Animal Auditor Certification Organization (PAACO) will certify the training of individual auditors and also the actual audit forms or processes of companies doing audits. PAACO will, in the future, provide training for people wanting to be certified to audit each species of farm animal, but who have not received training elsewhere.
Cash Flows of Instituting Reproductive Programs
Authors: Overton Michael W.
Published: February 2023

Economic returns associated with improved reproductive performance in dairy herds depend upon a wide variety of factors, including initial level of reproductive performance, future value of milk and of the calves produced, cash cost of replacement heifers, and many other factors. A variety of synchronization programs have been developed that may help improve the overall pregnancy rate (PR) of the herd, but the profitability of each program varies. A spreadsheet model was designed to compare the potential profitability of an improved estrus-detection program, an estrus-detection program combined with presynchronization and a single timed insemination, and a program relying completely upon timed insemination. Each of these scenarios was compared to a baseline program based upon estrus-detection and AI. The baseline herd was designed to have an estrus-detection risk and conception risk of approximately 50% and 31%, respectively, consistent with herds at or slightly above average reproductive performance in the US. Each of the modeled scenarios predicted better future returns than the initial baseline program, but the two involving timed AI also incurred substantial costs upfront. Adoption of either of these programs carries significant potential risk if not properly implemented and managed. Poor compliance to either timed AI program dramatically decreases both the resulting PR and the predicted economic returns. Dairies that implement programs such as these should work diligently to ensure that compliance levels consistently exceed 90% in order to maximize the profitability of either approach.
Pathogenesis of Diarrhea in Calves
Authors: Wagner Sarah
Published: February 2023

Calf diarrhea (scours) remains an important cause of illness and death in both dairy and beef herds. There are several viral, bacterial and protozoal pathogens that cause diarrhea in calves; many clinical cases of diarrhea result from infection by more than one pathogen. Infection with diarrhea- causing pathogens causes tissue damage and malfunction, which may lead to dehydration, electrolyte imbalances, acidosis, hypoglycemia, hypothermia, and other problems.
Effect of Castration Upon Arrival on Health and Performance of High Risk Calves During a 44 day Receiving Period
Authors: Burciaga-Robles L. O. , Step D. L. , Holland B. P.
Published: February 2023

The interaction between stress, the immune system, disease and performance of domestic animals has been reviewed (Breazile, 1998; Colditz, 2002). For beef cattle, the major stressor occurs when cattle are weaned, transported to a new environment, commingled and exposed to different pathogens, especially respiratory pathogens. In recent years, preconditioning programs have been developed, and although the specific components of each preconditioning program vary, they generally include weaning, castration, dehorning, deworming and vaccination against common respiratory pathogens (Peterson et al, 1989). According to Capucille et al (2002), beef cattle are castrated to prevent aggressive male behavior, control unwanted matings and to avoid consumer prejudices against beef from intact males. Based on a 1997 US National Animal Health Monitoring System report, surgical castration is the preferred method used by US cow-calf producers before weaning; however, post weaning techniques were not surveyed. This survey also reported that 25.5% of the cow/calf operations do not castrate their bull calves before selling them. Intact males represent a challenge for veterinarians and producers involved in backgrounding, stocker and finishing operations. Potential stress associated with post-weaning castration may include depressed immunity, expressed through the suppression of lymphocyte blastogenesis (Muratta, 1997) and interferon gamma production (Fisher et al, 1997). The objective of this study was to evaluate, in a controlled field study, health and performance of weaned calves arriving as bulls or steers during a 44-day receiving period.
Use of Treatment Records and Lung Lesion Scoring to Estimate the Effect of Respiratory Disease on Growth during Early and Late Finishing Periods in South African Feedlot Cattle
Authors: Thompson P. N. , Stone A. , Schultheiss W. A.
Published: February 2023

Bovine respiratory disease (BRD) is the most important disease of feedlot cattle worldwide, which, even in its subclinical form, negatively affects calf growth and therefore feedlot profitability. In order to accurately estimate the impact of BRD in the feedlot, it is necessary to account for both clinical and subclinical disease. Although most clinical cases occur during the first 3-6 weeks after arrival at the feedlot, the various persistent lung lesions may affect growth for a longer period of time. However, the effects of lesion type and extent and the time period during which they affect growth are uncertain. This study was done to estimate the effect of clinical and subclinical BRD, lung lesion type and lung lesion extent on growth during the early and late finishing period in South African feedlot calves.
Effects of Testing and Removal of Persistently Infected Bovine Viral Diarrhea Virus Feeder Calves on Morbidity and Mortality of Home Pen-associated Feeder Calves
Authors: Stevens E. T. , Thomson D. U. , Lindberg N. N.
Published: February 2023

Crossbred feeder calves (2,868 head 20 lots) were tested for bovine viral diarrhea virus persistent infection(BVD PI). The effects of testing and removal of persistently infected bovine viral diarrhea virus feeder calves on morbidity and mortality of home pen-associated feeder calves were determined.
Systematic Review of Johne's Disease Vaccination
Authors: Robbe-Austerman S. , Stabel J. R.
Published: February 2023

Johne's disease (JD) is a major health concern for the cattle and small ruminant industries world wide. Vaccination against JD has been in use since 1926, but has been controversial. Our objective was to conduct a systematic review of JD vaccination and do a metaanalysis of the data.
Effect of Sub-Clinical Manifestations of Bovine Paratuberculosis in Beef Cattle
Authors: Villarino Mario A. , Wikse S. E. , Jordan E. R.
Published: February 2023

Bovine paratuberculosis (Johne's disease) is a chronic, debilitating disease of cattle. Although widely known in the dairy industry, the effect of the disease in extensive ranch operations is unknown. Currently, testing techniques for bovine para tuberculosis in beef cattle are few, costly and somewhat inaccurate.We conducted the study of a beef herd located in Texas with the objective of evaluating the effect of subclinical manifestations of bovine paratuberculosis in beef cattle.
Quantifying Johne's Disease Infectivity in Dairy Herds in Indiana
Authors: Wu C. C. , Alinovi C. A. , Ward M. P. , Raizman E. A. , Lin T. L.
Published: February 2023

Infectivity is a critical parameter that determines how Johne's Disease agent (Mycobacterium avium subspecies paratuberculosis, MAP) survives in the population. Infectivity, in conjunction with contact rate, determines the numbers of new infection and, therefore the incidence and prevalence of infection in the population.
Immunology and Genetics
Authors: Mallard Bonnie A.
Published: February 2023

The immune system integrates innate and adaptive host defense mechanisms and is largely responsible for control of infectious disease. This system is under the tight genetic regulation of hundreds of genes. Some disorders are controlled by one or a few genes, while other more complex infectious diseases are controlled by many genes. Infectious diseases of livestock, including cattle, have become one of the most hazardous and expensive problems facing the agri-food industry. Many of these emerging and re-emerging diseases are zoonotic, causing concern to both animal and human health. Certain infectious diseases can be controlled by traditional methods; however, increasing restrictions on antibiotic use and the sizable costs associated with new drug development are making it more challenging to manage animal health. Therefore, alternative strategies are required for disease prevention that address these concerns for improved food safety and animal well-being. Given the role of the immune system in control of infectious disease, its genetic regulation, and that it is often possible to identify naturally immune individuals within a population, implementing thoughtful genetic strategies to enhance the immune system should help to improve inherent disease resistance. The emerging solutions integrate a variety of molecular and quantitative genetic approaches with both immediate and longterm improvements to animal health. This manuscript describes some of the strategies involving genetic regulation of the immune system.
Limited Intakes, Low Milk and Lost Income
Authors: Oetzel Garrett R.
Published: February 2023

Dairy practitioners can solve problems of low milk production in dairy herds by following a systematic approach to diagnose the underlying herd problems. Important steps in this evaluation are determining the herd signalment, objectively characterizing herd milk production and carefully evaluating herd nutritional management. Cows within the herd can then be observed for body condition score, cud chewing activity, manure characteristics, locomotion and evaluated for sickness. Important additional diagnostic information can be gleaned from herd turnover records and measures of cow comfort. Herd based testing for ketosis (BHBA and NEFA), subacute ruminal acidosis and urea nitrogen may be indicated depending on findings up to this point in the investigation. Fresh cow health problems (usually triggered by fatty liver and ketosis) or lameness (usually caused by a combination of cow environmental problems in combination with subacute ruminal acidosis) are the two most common mechanisms for low herd production. Expect to find multiple causes for low herd milk production, and put the most confidence in diagnostic conclusions that are supported by more than one measure of herd performance.
Monitoring of Rumen pH in Cattle Pulled for Bovine Respiratory Disease Complex with Normal or Elevated Rectal Temperatures in a Commercial Feedlot
Authors: Thomson D. U.
Published: February 2023

Cattle pulled to the hospital system for BRDC treatment did not have different rumen pH values regardless of their rectal temperature. Acidosis and BRDC both cause anorexia due to an undefined period of feed refusal or decreased feed intake in cattle. Possibly by measuring rumen pH after anorexia was detectable, cattle may have been off feed for a period of time long enough for rumen pH to normalize due to decreased substrate available for rumen fermentation. More researchin this area is warranted.
Effect of Bovine Viral Diarrhea Virus (BVDV) Persistent Infection on Gene Expression and Pro- and Anti-inflammatory Cytokine Levels
Authors: Tigabu B. , Kattelmann L. E. , Braun L. J. , Chase C. C. L.
Published: February 2023

This research indicates that eliminating the PI animal after diagnosis is likely the most prudent practice.
Diarrhea in Llama and Alpaca Crias
Authors: Cebra Christopher
Published: February 2023

Neonatal and juvenile diarrhea are common complaints among owners of cattle, sheep, pigs, horses, and goats. Microbial causes are usually blamed, although in some cases nutritional or other considerations come in to play. The most commonly identified pathogens are viruses and protozoa. These are relatively self-limiting, and clinical signs are more related to fluid and electrolyte loss than anything else. For ruminants and pigs especially, various products have been developed which specifically address water, base and salt loss. Various antibody and vaccine preparations are available to directly combat the causative organisms, but with the exception of Eimeria, antimicrobial treatment is usually not considered necessary.
Vaccination Practices in Cattle
Authors: Wagner Sarah
Published: February 2023

Veterinary technicians should have an understanding of how vaccines work and diseases for which cattle are commonly vaccinated. When the immune system responds to stimulation by an antigen contained in a vaccine, the animal actively acquires immunity. Attenuated (modified-live) or killed viruses or bacteria are antigenic; certain pieces (subunits) of bacteria are also antigenic. Vaccines must be handled with care, as sunlight, heat and disinfectants will decrease efficacy of vaccines. Animals which are malnourished, poorly housed, or otherwise under stress will have a decreased benefit from vaccination, as their immune systems will not properly respond. Vaccines in cattle are most commonly used to prevent respiratory, reproductive and clostridial diseases. Tetanus and blackleg are clostridial diseases. IBR, BVD, Pl3 and BRSVare viral respiratory and reproductive diseases which are commonly combined in one vaccine; the IBR and BVD components may be modified-live or killed. Brucellosis is not a common disease, but vaccination of cattle against brucellosis, a zoonotic reproductive disease ("Bang's disease") greatly facilitates interstate shipment. Products are available to vaccinate cattle against just about every infectious disease they can get, but not all available vaccines have proven efficacy. Decisions regarding vaccines to use on a particular farm should be based on the risks, management and unique needs of the farm. When properly selected, administered and used in conjunction with sound management practices, vaccination is a valuable tool to help maintain herd health.
Necropsy Techniques in Cattle
Authors: Wagner Sarah
Published: February 2023

Necropsy is used to diagnos disease in individual animals and to make decisions about the health and management of the herd. Veterinary technicians can and should participate in the performance of necropsy in cattle. Prior to beginning a necropsy, the veterinarian and technician should discuss which systems will be of particular interest during the necropsy examination, based on the history of the animal and the herd. The nearest veterinary diagnostic laboratory can describe which samples should be submitted for diagnosis of particular diseases, and how samples should be shipped to the lab. The most important tools for bovine necropsy are a sharp knife, pruning shears and a good working knowledge of the anatomy of cattle. It is always best to perform the necropsy as soon as possible after death, especially when the weather is warm. In both the chest and the abdomen, internal organs should first be examined as they lay in the body cavity; then they may be removed for further examination. Cattle with neurologic signs that test negative for rabies must be tested for Bovine Spongiform Encephalopathy, which requires submission of the obex area of the brainstem to a veterinary diagnostic laboratory. A thorough examination of an animal by gross necropsy can provide useful information in a relatively short time. Veterinary technicians can make a meaningful contribution to their practices by providing assistance with necropsy procedures.
Management Risk Factors Associated with Stillbirth
Authors: Vernooy E. , Leslie K. , Kelton D. , Hand K. , Muir B. , Duffield T.
Published: February 2023

The success of parturtion depends on a variety of cow and herd factors. It has been previously documented that the rate of stillbirth in Holstein cattle is approximately 10-15% in first parity animals and 5-7% in multiparous animals. Stillbirth is defined as delivery of a dead calf or a calf that is born alive but dies within the first 24 hours of life. Stillbirth can have both direct and indirect impacts on cow and calf health. Therefore, identification of key risk factors and implementation of changes to routine protocols aimed at reducing the occurrence of these calving disorders will benefit the dairy operation.
Trace Mineral Deficiencies (Cu, Se, Mg) Causing Reproductive Losses in a Purebred Angus Beef Herd
Authors: Schneider C. S.
Published: February 2023

Reported here are results of a herd investigation that was undertaken to resolve chronic poor herd reproductive and neonatal calf performance in a sixty head purebred Angus beef herd.
Effect of Varied Amounts of PBS and Time Before Application of PBS on the ACE for Detection of Calves Persistently Infected with Bovine Viral Diarrhea Virus
Authors: Funk R. A. , Thomson D. U. , Rust R. L. , White B. J. , Renter D. G.
Published: February 2023

The identification and removal of persistently infected (PI) animals from a production system is a key component to controlling BVD. In order to achieve this, a reliable method of testing for PI animals must be used. Ear notching is a common and easy way to obtain diagnostic samples in a relatively non-invasive manner. Previously these tissue samples were examined by immunohistochemistry for the presence of the BVD virus in the epithelium. Recently, advancements have been made that allows the testing of a phosphate buffered saline ear notch extract by enzyme linked immunosorbent assay (ELISA). This technique of detecting BVD infected animals is much more rapid than the conventional IHC testing. Additionally, ELISA testing methods do not require the level of specialized equipment or number of personnel that other methods such as ear-notch immunohistochemistry or polymerase chain reaction require, and readily adapt themselves to automation.