bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of castration on weight gain of beef calves
Authors: Baker J. F. , Strickland J. E. , Vann R. C.
Published: March 2023

Many management practices can be utilized to maximize weight and increase value of calves at weaning. Combining the two management practices of castration and implanting male calves allows producers to maximize weaning weights and avoid discounts for intact males. Crossbred bull calves were randomly assigned at birth to 1 of 3 treatment groups: castrated (n = 22), banded (n = 18) or left intact (n = 20). Calves that were castrated or banded within 24 h after birth received a zeranol implant at that time. Calves in the intact group were castrated at 150 days of age and then implanted, and the calves in the other 2 treatment groups were re-implanted at that time. There were no differences in weaning weight, average daily gain (ADG) or weight per day of age between the 3 treatment groups. Castrating calves shortly after birth reduced stress on the animal compared to castration at a older age (day 150 to weaning). Also, early castration may be more acceptable as an animal welfare issue. It is concluded that combining castration and implanting allows producers to maximize weaning weight of calves as well as reduce the stress of castration at an older age.
Hematologic abnormalities over 5 days in cows with acute Escherichia coli mastitis
Authors: Cebra Christopher K. , Cebra Margaret L. , Garry Franklyn B.
Published: March 2023

Haematological data from 45 adult Holstein cows with coliform mastitis and systemic clinical signs were studied retrospectively. They developed panleukopenia that resolved over several days, first through an increase in immature forms and later by an increase in mature neutrophils. Neutropenia lasted 3 days in most cows. The majority of cows in early lactation did not develop neutropenia for an unknown reason. Cows with fatal disease could not be distinguished based on haematological analysis, because most died early in the disease, while both surviving and non-surviving cows still had panleukopenia. Cows with coliform bacteraemia had prolonged neutropenia and higher metamyelocyte and myelocyte counts during the regenerative phase. These findings suggest that haematological analysis during the regenerative phase may be useful to identify cows with bacteraemia for more aggressive treatment.
Mycoplasma infection in cattle
Authors: Step D. L. , Kirkpatrick John G.
Published: March 2023

Mycoplasma spp. are unique microorganisms associated with several disease entities, including a pneumonia-arthritis syndrome in cattle. One of the challenges in determining the role of Mycoplasma spp. in bovine disease is that this organism has been isolated from both normal and diseased animals. When dealing with field cases of mycoplasma pneumonia, it is common to find mixed infections. Additionally, observations from research studies and clinical experience have indicated that the presence of mycoplasma increases the severity of respiratory disease. There are no pathognomonic signs for mycoplasma infections. Clinical signs associated with respiratory infections include tachypnea, dyspnea, ocular and nasal discharge, depression, decreased appetite, arched stance and fever. Clinical signs associated with joint infections includestiffness, lameness, difficulty when rising, swollen joints and tendon sheaths, decreased appetite and weight loss. The organism requires special growth media and conditions to be cultured in the laboratory. If a practitioner wants to confirm a diagnosis with a positive culture, he/she must specifically request a mycoplasma culture when samples are submitted to the laboratory. Besides determining the significance of Mycoplasma spp. in disease, the practitioner is faced with recommending appropriate and effective treatments. Response to therapy, both experimentally and under field conditions, is variable and frequently unrewarding. Since mycoplasma organisms are resistant to several therapies, sound biosecurity and biocontainment programs that minimize stress and exposure to the organism are the best recommendations that practitioners can discuss with producers for prevention and control.
Using teat endoscopy (theloscopy) to diagnose and treat milk flow disorders in cows
Authors: Geishauser Thomas , Querengasser Klaus
Published: March 2023

Theloscopy or endoscopic examination of the teat is used to diagnose milk flow disorders, visualize the cistern during surgery and monitor teat response to treatment. This article describes the procedure and equipment used for theloscopy of the bovine teat.
Mycoplasma infection in cattle
Authors: Step D. L. , Kirkpatrick John G.
Published: March 2023

Mycoplasma spp. have been associated with many disease entities in cattle including mastitis, keratoconjunctivitis, otitis media, decubital abscesses, meningitis, reproductive problems and the pneumonia-arthritis symdrome. Since there are no pathognomonic signs to aid in making a clinical diagnosis, diagnosis of Mycoplasma infections presents a challenge to practitioners. Culture with identification of the organism and other ancillary tests are required for definitive diagnosis. Failure to respond to treatment is common. Isolation/segregation and culling infected or carrier animals are the best recommendations for control and prevention of Mycoplasma infections in a herd. In a companion paper, the pneumonia-arthritis syndrome was discussed. This paper reviews other disease entities caused by Mycoplasma spp.
Importance of preventing bovine respiratory disease
Authors: Speer N. C. , Young C. , Roeber D.
Published: March 2023

Segmentation within the beef industry creates differing perspectives of the true worth of cattle. This is especially apparent for cattle that have been managed through some type of value-added health program. Understanding each segment?s role in value integration becomes increasingly important as vertical cooperation increases within the industry. Sickness, usually manifested as Bovine Respiratory Disease (BRD), in newly received calves illustrates the importance of preweaning health management to cattle buyers because it is directly related to economic risk. Morbidity rates can have a dramatic economic impact because of losses associated with mortality realizers, reduced performance and carcass value reduction. Health programs are designed to minimize morbidity risk of feeder cattle, and to provide some method of documenting the preventive management program conducted prior to sale. A variety of programs exist to compliment varying cow/calf management schemes. Preconditioning programs represent the most comprehensive tool to prevent morbidity upon arrival. Preconditioning programs address both sides of the morbidity equation: they are designed to reduce the incidence of BRD by increasing resistance, while simultaneously reducing stress prior to and after shipment. However, the cattle industry has been slow to adopt preconditioning programs. This has occurred primarily as a result of ranchers' efforts to reduce input costs, along with increasing consolidation within the feeding industry Nonetheless, source-verified, preconditioned calves generally are at reduced risk of morbidity, thereby potentially reducing feedyard operating costs. The cost of disease prevention programs and their effect on morbidity must be appropriately evaluated, however, within the given economic environment. Calf producers and practitioners are encouraged to understand the various factors that cause variability in feeder cattle prices in order to reduce exposure to excessive market risk, and maximize net return of the cattle that they produce.
Case report
Authors: Niles G. A. , Morgan S. E. , Edwards W. C.
Published: March 2023

A central nervous system disease occurred in a group of beef steers placed into confinement feeding pens during a period of prolonged drought and high environmental temperatures in Oklahoma, USA (September 2000). The steers began exhibiting neurological signs during the 3rd week after placement into the pens. Microscopic examination of brain tissue revealed lesions consistent with polioencephalomalacia. Tissue analysis for lead and evidence of water deprivation-sodium ion toxicity were negative. The steers had been drinking well water containing 3000 ppm sulfate. In addition, the total mixed ration contained 2950 ppm total sulfur. Total sulfur intake was calculated to be 77 g of sulfur per steer per day, which equated to 1% (10?000 ppm) of the ration on a dry matter basis. Based upon clinical signs, histopathology and high levels of sulfate and sulfur in the water and feed, respectively, a diagnosis of sulfur-induced polioencephalomalacia was made. No further cases occurred after the steers were provided water with low sulfate content.
Anatomical measurement of sole thickness in cattle following application of two different trimming techniques
Authors: Van Amstel S. R. , Palin F. L. , Shearer J. K. , Robinson B. F.
Published: March 2023

Thin soles with complications and lameness have become a major problem in large dairies within the US. The cause is multifactorial, including excessive removal of sole horn during maintenance claw trimming procedures. This study compared sole horn thickness after trimming, using two commonly practiced trimming methods. Cadaver legs were divided into 3 groups: group 1 (non-trimmed group, n=90); group 2 (Dutch Trimmed group, n=66); and group 3 (White Line Trimmed group, n=48). An adaptation of the Dutch trimming method resulted in significantly fewer thin soles as compared to the second method where the white line was used as an appraisal for sole horn thickness.
Dinoprost Versus Cloprostenol
Authors: Martineau Roger
Published: March 2023

This factorial study was conducted to determine the reproductive performance of402 dairy cattle treated with either dinoprost (25 mg) or cloprostenol (500 pg), intravenously (IV) or intramuscularly (IM), for synchronization of estrus in a randomized clinical trial. Breeding, conception and pregnancy rates were analyzed with multivariate logistic regression. The model included the treatments (2 types of prostaglandins and 2 routes of injection) as well as eight clinically-relevant covariables. Interactions between treatments were not significant and comparisons were made on the main effect. Comparisons between types of prostaglandins (PGF2a) showed similar breeding rates (82.6 vs 83.0%; P=0.93), but lower conception rate (38.6 vs 46.6%; P=0.13) and pregnancy rate (31.4 vs 39.2%; P=0.14) for dinoprost versus cloprostenol. When comparing routes of injection, a similar breeding rate (84.1 vs 81.4%; P=0.45), but lower conception rate (38.7 vs 46.7%; P=0.13) and pregnancy rate (32.5 vs 38.1%; P=0.23) were noted for IM versus IV injections. The statistical power of the study was 19%, which allowed detection (P<0.05) of a 5% difference or more in pregnancy rate between the main effect of treatments (200 animals per sample).Gender of calves was recorded on 117 calves and analyzed with univariate logistic regression. Overall, the male calf rate was not different from the expected population value (57.3 vs 53.0%; P=0.36). There was a greater proportion of male calves when using dinoprost compared to cloprostenol (72.3 vs 47.1%; P<0.01), when using IV rather than IM injections (66.1 vs 49.2%; P=0.07) and when inseminating cattle 4 days or later after PGF2 injection instead of earlier (69.4 vs 51.9%; P=0.08). It is concluded that the type of PGF2a used and the route of injection might affect conception rate and hence, pregnancy rate, and that the statistical power of the study was too weak to detect any significant differences. It is also concluded that the interval (days) from PGF2a injection to breeding, the type of PGF2a and the route of injection might influence the sex ratio of calves.
Review of Inherited Central Nervous System Dysfunction in Calves
Authors: Washburn Kevin E. , Streeter Robert N. , Panciera Roger J.
Published: March 2023

Differentiating inherited central nervous system diseases in calves from non-inherited disorders is important due to significant ramifications to the herd breeding program and the poor prognosis associated with them.Well documented and suspected inherited conditions that cause central nervous system (CNS) dysfunction in calves include progressive degenerative myeloencephalopathy, spinal muscular atrophy, degenerative axonopathy, spinal dysmyelination, citrullinemia, cerebellar abiotrophy, progressive ataxia, spastic paresis, maple syrup urine disease, neuraxial edema, bovine familial convulsions, storage diseases, neuronal lipodystrophy and myelodysplasias.This review briefly describes the signalment and common clinical signs of many proven or presumably inherited conditions that cause CNS dysfunction in calves. These diseases are categorized by localization of the predominant signs into dysfunction of the spinal cord, cerebrum, cerebellum or multiple regions of the central nervous system. Detailed descriptions of pathologic lesions are beyond the scope of this article, however, the general location of these lesions is described to facilitate selection of appropriate samples for diagnostic testing. A brief review of the location of lesions and their relationship to clinical signs is provided. Some non-inherited conditions are briefly discussed to differentiate the many causes of CNS dysfunction in calves.
Review of the relationship between persistent infection of cattle with bovine viral diarrhea virus and feedlot morbidity and gain
Authors: Moczygemba Larry
Published: March 2023

Bovine viral diarrhoea is an infectious viral disease of cattle. Persistently infected cattle result from in-utero infection of calves with the bovine viral diarrhoea virus during critical stages of gestation, and affected calves become lifetime carriers of the virus. Cattle persistently infected with the virus can be a source of infection to healthy pen mates in a feedlot setting. The feedlot industry is a cost-driven, low-margin business, and cattle need to perform efficiently to be profitable. Morbidity can have a significant impact on profitability. This paper reviews the relationship between calves persistently infected with bovine viral diarrhoea virus and the health and performance of feedlot cattle at the pen level.
Case report
Authors: Figueiredo M. D. , Perkins G. A. , Ospina P.A. , Brognano C. , Peters R.M. , DeLahunta A.
Published: March 2023

Two first-calf heifer Holstein herd mates were admitted to the veterinary teaching hospital with a one- to two-week history of hind limb weakness. Both heifers had recently freshened (25-30 d) and had their tails docked with castration bands at parturition. The chief presenting clinical signs for both cows were bilateral hind limb weakness, over-flexion of the hocks and occasional over-flexion (dorsal knuckling) of the fetlocks. Other pertinent physical examination findings included weak anal and tail tone. These clinical signs are diagnostic for tibial and sacro-caudal nerve damage. No significant abnormalities were found on preliminary blood examination. Due to the poor prognosis for return to function, both cows were euthanized and a postmortem examination was performed. Postmortem examination revealed chronic suppurative discospondylitis at the sixth lumbar vertebrae and first sacral vertebrae (L6-S1). Escherichia coli was cultured from the L6-S1 disk space of one cow (case 1); no other significant abnormalities were found on postmortem examination. It was uncertain if the infection was secondary to an ascending infection from the tail-docking site, however, there was no evidence of generalized bacteraemia or other sources of infection.
Evaluation of a treatment protocol for intramammary infections in early postpartum dairy cows based on a positive California Mastitis Test result
Authors: Wallace J.A. , Stipetic K. , Schukken Y. H. , Dingwell R. T. , Baillargeon P. , Bacic G. , Leslie K. E.
Published: March 2023

Recent studies have evaluated the use of the California Mastitis Test (CMT) in early postpartum cows to identify intramammary infections (IMI). Whether the CMT is used to identify cows for culture or for herd-level udder health monitoring, many producers are in a dilemma when faced with a positive CMT result. The purpose of the study was to evaluate the effectiveness of an intramammary treatment protocol based on a positive CMT result within the first three days of calving. In addition, the effect of early intramammary antibiotic therapy on cure rates, linear somatic cell score (LS) and milk production for the first three Dairy Herd Improvement (DHI) tests postcalving were assessed. A total of 1861 quarters, representing 561 cows from 24 commercial herds, were enrolled. All quarters from each cow were tested by the dairy producer using the CMT, and sampled aseptically for milk bacteriology between calving and three days-in-milk (DIM). Cows with a positive CMT (n=180) were randomly assigned to receive either intramammary (IMM) cephapirin sodium, or no treatment. A CMT with any reaction was considered positive. All CMT-positive cows were sampled for bacteriological culture between 10-16 DIM to determine cure of infections. Cure rates were evaluated using data from 138 treated and 117 control quarters. Cure rates for all major pathogens for the treated and control group were 84.6 and 71.7%, respectively. This difference was not statistically significant. However, cure rates for environmental streptococcal infections for the treated and control group, 89.4 and 70.82%, respectively, were statistically different (P=0.05). Cows that recovered from infection with a major pathogen had a decrease in linear score. As LS decreased, milk production increased. When milk production was evaluated, it was demonstrated that as the CMT score increased, cows had a 2.1-kg decrease in milk production per test date. The antibiotic treatment groups were not significantly different for LS or milk production by the third test date. In conclusion, this fresh cow protocol was most effective to reduce IMI due to environmental streptococci and reduce LS. Therefore, blanket therapy of all CMT-positive cows may not be justified. Udder health status and predominant mastitis pathogen within the herd need to be considered when developing treatment protocols.
Dairy production medicine in the United States
Authors: Fetrow John , Cady Roger , Jones Gordon
Published: March 2023

Consolidation of the dairy industry in the United States over the next decade will secure the transition of dairy farms to a new model of larger, "scale-adapted" dairies. With that change, the demand for dairy veterinarians in a traditional practice role will decline and the roles played by those that remain will change. Dairy veterinary medicine will largely shift from a "hands-on" technical role to a role in consultation, dairy management and at higher levels in the food and production chain. Veterinary education will need to change as well to respond to these trends.
Modified-live bovine viral diarrhea virus (BVDV) type 1a vaccine provides protection against fetal infection after challenge with either type 1b or type 2 BVDV
Authors: Schnackel John A. , Van Campen Hana , Van Olphen Alberto
Published: March 2023

The objective of the study was to determine the efficacy of modified-live virus (MLV) BVDV type la (BVDV1a) vaccine against BVDV type 2 (BVDV2) or type 1b (BVDV1b) virus in fetal calves. The experimental vaccine administered to the cows and heifers had a minimum antigen load dose of MLV BVDV1a and a full (commonly marketed) antigen dose of infectious bovine rhinotracheitis (IBR), parainfluenza-3 (PI3), bovine respiratory syncytial virus (BRSV), and Leptospira serovars canicola, grippotyphosa, hardjo, icterohaemorrhagiae and pomona (Lepto-CGHIP) bacterin. In Trial A, 25 pregnant vaccinated cows and heifers and 10 pregnant unvaccinated controls were challenged with BVDV2. In Trial B, 25 pregnant vaccinated cows and heifers and eight pregnant unvaccinated controls were challenged with BVDV1b. In both trials, fetuses were obtained by Cesarean section, which was performed after ?150 days of gestation (range 148-174 days), and the presence or absence of fetal BVDV infection was determined. All control fetuses were infected with BVDV. In Trial A, all fetuses (n=25) of vaccinated dams were free of BVDV infection. In Trial B, one cow did not have a fetus at 150 days of gestation, and out of the 24 fetuses, 23 were negative and one fetus was positive for BVDV. These results suggest that vaccination with MLV BVDV1a vaccine significantly reduce fetal infection following challenge with BVDV2.
Herd prevalence and risk factors of Leptospira infection in beef cow/calf operations in the United States
Authors: Wikse Steven, E. , Rogers Glenn M. , Ramachandran Satheesh , Engelken Terry J. , Epperson William B. , Larson Robert L. , Maas John , Richey Ed , Bolin Carole
Published: March 2023

The herd prevalence of Leptospira borgpetersenii serovar hardjo infection and associated risk factors were determined for beef cow/calf operations in California, Florida, Mississippi, Missouri, South Dakota and Texas, USA. Three veterinary practitioners randomly selected in each state completed a questionnaire on herd management practices, and collected blood and urine from 10 to 15 cows in four randomly selected herds. Serum samples were tested for antibodies against Leptospira borgpetersenii serovars grippotyphosa, hardjo, icterohaemorrhagiae and pomona using the microscopic agglutination test. Urine sediments were stained with a non-serovar specific fluorescein-labeled anti-Leptospira antibody conjugate. Herd infection with L. borgpetersenii serovar hardjo was inferred if one or more cows had leptospires in their urine accompanied by either high antibody titres to the organism, or low titres to it and low titres against L. borgpetersenii serovars grippotyphosa, icterohaemorrhagiae and pomona. 28 (42%) of the 67 herds had results compatible with infection with L. borgpetersenii serovar hardjo. Herds in South Dakota had a significantly lower prevalence than herds in other states (P=0.01). A greater likelihood of infection with L. borgpetersenii serovar hardjo was found in herds with higher mean annual temperatures (P=0.02) and longer breeding seasons (P=0.02). It is recommended that altering risk factors that predispose herds to infection, such as shortening length of breeding season will increase the effectiveness of programmes to control this disease.
Management of infertility due to unilateral segmental aplasia of the paramesonephric (Mllerian) duct in Holstein Friesian cattle
Authors: Riley Christopher B. , Kulik Kim , Crane Melvin , Robbee Frank , McKenna Shawn B. L.
Published: March 2023

Segmental aplasia of the paramesonephric (Mllerian) duct (SAP) is an infrequently reported cause of infertility, with few cases reported in North America in the last 30 years. The objectives of this paper are to report the findings and outcome of 17 Holstein Friesian cows recently diagnosed with this condition, and to review and discuss the current genetic and economic considerations in managing this condition in breeding dairy cattle. The possible genetic basis of this condition in the Holstein and other breeds is reviewed, as are the possible molecular aetiologies. Management challenges and options are discussed, as are the needs for centralized reporting and elucidation of SAP in North American Holsteins.
Efficacy of a new sustained-release intraruminal selenium bolus
Authors: Renquist B. J. , Oltjen J. W. , Sween M. L. , Flavell D. K. , Maas C.
Published: March 2023

Our objective was to test the efficacy of a new sustained-release selenium (Se) bolus versus negative and positive control beef cattle. Fifty-five English breed heifers (mean initial body weight 546ñ46 lb; 248ñ 21 kg) were randomly assigned to one of four treatment groups: one 120-day, sustained-release selenium (Se) bolus on day 0 (A-1X); one 120-day, sustained-release Se bolus on day 0 and a second bolus on day 121 (A-2X); one 365-day, sustained-release Se bolus on day 0 (B); and control (C), no supplemental Se. Heifers grazed Se-deficient native foothill range without any additional supplement. Body weights and blood samples were taken for Se analysis from animals in all four groups at days -28, 14, 28, 49, 63, 121, 183, 293 and 365. No evidence of excess Se intake was observed. Both blood and weight data were analyzed in a model with Se treatment as the main effect; a log transformation for blood Se was used to make variances across treatments similar. Blood Se concentrations were similar amongst treatment groups on day -28. However, on days 14, 28, 49, 63, 121, 183, 293 and 365, blood Se concentrations were higher for the three supplemented groups relative to the control group (P<0.0001). On day 121, Groups A-2X and B had higher blood Se levels than Group A-1X (P=0.0001 and 0.0046, respectively). At days 183 and 293, Group A-2X had the highest blood Se concentrations (231.1ñ22.7 and 133.4ñ13.4 ng/ml), with Groups B (136.8ñ23.0 and 75.8ñ17.9 ng/ml), A-1X (114.3ñ16 and 34.8ñ8.8 ng/ml), and C (21.26ñ2.8 and 15.53ñ2.7 ng/ml) having descending Se blood concentrations, respectively. On day 365, Groups A-2X and B had blood Se concentrations above the 50 ng/ml that is considered deficient. Groups A-1X, A-2X and B gained 25.1, 51.0 and 25.7 lb (11.4, 23.2 and 11.7 kg) more than the 219.6 lb (99.8 kg) gain of the control group (P<0.001). Selenium supplementation provided sufficient mineral to raise blood Se concentrations above deficient levels. When compared with a single 120-day bolus, the single 365-day bolus prevented blood Se concentrations from falling to deficient levels for a longer period of time.
Effects of frequent functional foot trimming on the incidence of lameness in lactating dairy cattle
Authors: Smith B. I. , Kristula M. A. , Martin D.
Published: March 2023

A 36-month field trial was conducted to determine the effect of frequent functional foot trimming on lameness. Six hundred and thirty-eight (638) lactating dairy cattle in a southwestern Pennsylvania commercial herd were subjected to functional foot trimming either once a year (control group - CG) or three times a year (foot treatment group - FTG). FTG cattle were trimmed as a group in May, September and January; CG cattle were trimmed at dry-off. All cattle were managed the same during the trial period. The overall reduction in all foot lameness by treatment was 27% when controlling for a previous history of lameness and lactation number, but results were not significant (P=0.15). Cows in the FTG group were 52% less likely to develop a sole ulcer compared to CG cows (P=0.05). Overall, cows with a previous history of lameness were 6.4 times more likely to become lame and 3.1 times more likely to develop a sole ulcer. There was no difference in risk of being culled between FTG and CG cows. In addition, there was no difference in lameness for first-lactation heifers (prospective heifers) assigned to either the FTG or CG after the study began, suggesting that more research is needed to establish the benefit of a single functional foot trimming compared to an untreated control group in first-lactation heifers. Although results from this study and others suggest a reduction in lameness for cows trimmed more frequently than once a year, further studies with larger numbers of cows from multiple herds are needed to make definitive conclusions regarding the overall benefit of frequent functional foot trimming.
Tolazoline
Authors: Lin Hui-Chu , Riddell M. Gatz
Published: March 2023

The objective of this study was to investigate the dose response effects of intravenous administration of tolazoline and to characterize the side effects associated with these doses in Holstein calves. Six healthy calves (mean body weight 352.7 ± 87.8 lb; 160.3 ± 39.9 kg) were used in the study. Seven doses (0.23, 0.45, 0.68, 0.91, 1.82, 3.64 and 4.55 mg/lb; 0.5, 1, 1.5, 2, 4, 8 and 10 mg/kg) of tolazoline administered intravenously via jugular vein were studied. Calves were allowed to recover over a period of seven days between each experiment. Heart rate, respiratory rate, mucous membrane color and capillary refill time were recorded before drug administration and at 10 minute intervals for 90 minutes after drug administration. Signs of adverse effects such as anxiety, excitement, CNS depression, salivation, bright red mucous membrane color, sweating, piloerection, trembling, hyperesthesia on the head and neck, muscle weakness, recumbency, dyspnea, abnormal breathing patterns, abdominal pain and diarrhea were recorded. At lower doses (≤0.68 mg/lb; 1.5 mg/kg), administration of tolazo-line caused coughing, increased frequency of defecation and mild increase in breathing effort. At higher doses (0.91-4.55 mg/lb; 2-10 mg/kg), adverse effects such as bright red conjunctival mucous membrane, coughing, nasal discharge, salivation, increased breathing effort (labored breathing), CNS depression, signs of abdominal pain, straining, head pressing, restlessness, increased frequency of defecation and diarrhea were observed. All calves recovered.
Comparison of 3-, 5-, 7- and 10-day Post-metaphylaxis Evaluation Periods on Health and Performance Following On-arrival Treatment with Tilmicosin in Feeder Cattle
Authors: McClary David G. , Corbin Marilyn J. , Carter Brandon , Homm Justin , Vogel Gary , Platter William , Gunthrie Carl A.
Published: March 2023

Two 60-day studies were conducted comparing various post-metaphylaxis evaluation periods (PMEPs) following administration of tilmicosin to beef feeder cattle at arrival-processing. Calves in Study I were randomly assigned to a control group (no metaphylaxis) or administered tilmicosin at label dose (4.55 mg/lb; 10 mg/kg BW) and assigned to a 3-, 5- or 7-day PMEP (n=160 calves per treatment). Morbidity due to bovine respiratory disease (BRD) was reduced (P <0.01) in calves treated metaphylactically with tilmicosin compared to controls (9.6 vs 33.8%, respectively). Average daily gain (ADG) was improved ( P <0.05) in all three PMEP groups compared to gain of calves in the control group. Calves in Study II were randomly assigned to a control group (no metaphylaxis) or administered tilmicosin at label dose and assigned to one of four PMEP (3-, 5-, 7- or 10-days) groups (n=140 per treatment). Morbidity caused by BRD was reduced ( P <0.05) in all tilmicosin metaphylaxis groups compared to controls (55.7, 56.4, 52.1, 39.3 and 69.3% for the 3-, 5-, 7- and 10-day PMEP groups and controls, respectively). The morbidity rate due to BRD was lower ( P <0.01) in the 10-day PMEP group compared to other PMEP groups, however, mortality in this group was numerically higher than the other PMEP groups. There was no difference in ADG among treatments. Calves diagnosed with clinical BRD following the PMEP and control calves showing signs of BRD were treated with tulathromycin (1.14 mg/lb; 2.5 mg/kg BW) in both studies. Treatment success was similar across all treatments in each study, but was numerically higher in Study I (88.0%) compared to Study II (66.8%).
Voluntary Colostrum Intake in Holstein Heifer Calves
Authors: Urday Kelvin , Chigerwe Munashe , Tyler Jeff W.
Published: March 2023

An observational study was done to determine voluntary colostrum intake at the first feeding in nipple bottle-fed Holstein heifer calves. Thirty-two Holstein heifer calves resulting from observed births were hand fed using a nipple bottle for a total of 15 minutes at two hours of age. Each calf was offered a maximum of 3 liters (L) total intake. Median colostral intake was 2.34 L with a range of 0.0 to 3.0 L. Ten (31.25%) calves consumed less than 2 L and 14 calves (43.75%) consumed the maximum 3 L offered. Exclusive voluntary intake using a nipple bottle is an inadequate method of colostrum administration unless more rigorous feeding practices than those described are used. Under conditions of limited labor availability, bottle-fed calves should be offered an unlimited volume of colostrum at the time of the first feeding, and tube fed using an oroesophageal feeder if they fail to ingest a minimum of 2 L in a timely manner. This practice improves the likelihood that calves will achieve consistent, adequate passive transfer of colostral immunoglobulins.
Characterization of sulfur and sulfate toxicosis in cattle
Authors: Lamm Catherine G. , Richter Grace , Taylor Jared D. , Morgan Sandra E.
Published: March 2023

Sulfur and sulfate toxicoses are important causes of polioencephalomalacia (PEM) and feed refusal in cattle, resulting in decreased weight gain and increased death losses. The purpose of the study was to characterize the demographics of cattle with sulfur/sulfate toxicosis (ST), describe clinical signs and pathology associated with disease, and to identify potential sources of high sulfur/sulfate. Cattle submitted between August 2005 and April 2009 were separated into three groups: Group A had neurologic signs or histologic evidence of PEM, as well as confirmed exposure to elevated concentrations of sulfur/sulfate; Group B had neurologic signs and/or histologic evidence of PEM but no confirmed exposure to elevated concentrations of sulfur/sulfate; Group C had confirmed exposure to high sulfur/sulfate although no record of any pathology or clinical signs associated with ST. The following information was recorded when available: age, gender, production type, month of submission, clinical signs, pathology, and source of elevated concentrations of sulfur/sulfate. Statistical analysis was performed on data from Group A. Affected cattle were more likely to be females between three and 16 months of age (age, P<0.001; gender, P=0.022). A seasonal trend was not detected. Clinical signs in Groups A and B included neurologic signs and gastrointestinal problems (18/29); sudden death was reported in 11/29 cattle. Cattle in Groups A and B had PEM (16), meningoencephalitis (2), cerebral edema (1), gliosis (1), abomasitis (3), and/or cardiac or skeletal muscle degeneration, necrosis, and/or inflammation (5). Undifferentiated feeds were the most common source of sulfur/sulfate toxicosis.
Survival of bovine viral diarrhea virus on materials associated with livestock production
Authors: Stevens Elliot T. , Thomson Daniel U. , Wileman Ben W. , O'Dell Sean , Chase Christopher C. L.
Published: March 2023

Fomites have been shown to play a role in the transmission of bovine viral diarrhea virus (BVDV). However, there are no published reports on the length of time BVDV can survive on fomites. In the current study, we applied a type 1b, non-cytopathic (NCP) BVDV isolate to clothing, materials common to livestock production settings, and various feedstuffs. Additionally, we created a synthetic mucus phosphate buffered saline (PBS) solution and added BVDV to determine whether mucus impacted BVDV survival. Overall, the ability to recover BVDV after application to potential fomites decreased as the length of incubation increased. The BVDV strain tested in this study exhibited longer survival times in two aqueous solutions (water and PBS), two non-porous materials (latex and enameled metal), and one porous material (paper) than in other potential fomites. One non-porous material (galvanized metal) and two porous materials (soil and pine) tended to have a lower chance of BVDV recovery. No virus was recovered from denim, cotton t-shirt, mineral and salt blocks. For the total mixed ration, BVDV was recovered in one replicate, for up to eight hours post-application; however, all other replicates were negative. The molasses-urea lick in all three replicates was contaminated, therefore they were not tested. Based on these findings, a type 1b, NCP BVDV was capable of surviving after application to various materials used in livestock production. In the presence of mucus, BVDV was protected from degradation for longer periods of time.
Current challenges in the diagnosis and control of bovine anaplasmosis
Authors: Kocan Katherine M. , Coetzee Johann F. , Step Douglas L. , De la Fuente Jose , Blouin Edmour F. , Reppert Emily , Simpson Katharine M. , Boileau Melanie J.
Published: March 2023

Bovine anaplasmosis, caused by the intracellular rickettsia Anaplasma marginale, continues to impact cattle production in the US. Control and management of bovine anaplasmosis is influenced by our understanding of the complexity of this pathogen, interactions with both cattle and tick hosts, and the disease. A. marginale is maintained in nature through biological transmission by ticks and mechanical transmission by any means of blood transfer from infected to susceptible cattle. The major surface protein 5 (MSP5)-based cELISA, approved for use in the US and Canada, has proven to be a sensitive serologic test. However, more recently this test has been shown to be cross-reactive with closely related organisms, including A. phagocytophilum, because of the conservation of MSP5. Therefore, additional molecular tests may be required in some situations to confirm the identity of the infective agent. While tetracycline antimicrobials are approved by the US Food and Drug Administration for prevention or treatment of acute anaplasmosis, no antimicrobials are labeled for elimination of persistent A. marginale infection. Administration of tetracyclines is an important means of preventing clinical anaplasmosis, but does not prevent cattle from becoming infected with A. marginale. The mode of action of tetracycline is bacteriostatic rather than bactericidal, and its long-term use does not consistently clear cattle of persistent A. marginale infections. USDA approved vaccines for anaplasmosis are currently unavailable. The challenges of vaccine development include the antigenic variation of A. marginale that occurs during persistent infections and the increased antigenic diversity of A. marginale strains, especially in areas of ongoing cattle movement. The overall goal of this and a previous overview is to summarize the current status of knowledge and research on bovine anaplasmosis, and to provide veterinarians with answers to frequently asked questions.
Evaluation of FTA cards as a sample collection method for detection of BVDV in persistently infected beef cattle
Authors: Foster Celeste , Hoar Bruce , Hessman Bill E. , Crossley Beate
Published: March 2023

The accuracy of test outcome is directly related to the quality of samples arriving at the diagnostic laboratory. However, in certain field situations sample storage conditions may be less than optimal. Flinders Technology Associates (FTA) cards are a sample collection and storage tool suitable for field conditions. For the evaluation of FTA cards, nasal swabs and EDTA blood samples were collected by traditional methods from a group of known bovine viral diarrhea virus (BVDV) persistently infected (PI) animals, as well as from animals in a herd never diagnosed with BVDV infection. Diagnostic performance parameters of the reverse transcription real-time PCR assay (RT-r PCR) were compared between whole-blood and nasal-swab samples collected onto FTA cards from the same animals taken at the same time. Sensitivity and specificity based on the dichotomous classification of BVDV-positive or negative were 100% for the samples collected using traditional methods, and for those collected onto FTA cards. Real-time PCR cycle threshold values demonstrated a lower analytic sensitivity for samples collected onto FTA cards, although samples from FTA cards correctly identified all PI animals tested. One animal from the PI group tested BVDV-positive only in the nasal specimen, suggesting the positive resulted from contact exposure rather than from systemic viral production. To further evaluate the potential of the FTA cards, a subset of BVDV-positive samples (n=29) were sub-typed by direct sequencing of the BVDV qRT PCR products obtained from the case material. BVDV-1 was detected in 75.9% (22/29) of cases, BVDV-2 in 13.8% (4/29) of cases, and both serotypes were simultaneously detected in the remaining 10.3% (3/29) cases. Time savings associated with use of FTA cards for sample collection was calculated to be 23.5 seconds per blood sample. The FTA cards provide a method for diagnostic sample handling that helps overcome sample quality issues associated with improper storage conditions and shipping concerns.
Current feedlot cattle health and well-being program recommendations in the United States and Canada
Authors: Lee T. L. , Terrell S. P. , Bartle S. J. , Apley M. D. , Rethorst D. , Thomson D. U. , Reinhardt C. D.
Published: March 2023

Feedlot consulting veterinarians (n=23) in the United States and Canada participated in a beef cattle health and well-being recommendation survey. The objective of the survey was to determine the recommendations of consulting feedlot veterinarians in the United States and Canada for cattle health and well-being, and to compare these recommendations to those made in a survey conducted in 2009. Participants answered 78 questions on feeder cattle husbandry, health, and preventative medicine recommendations. Survey results showed that veterinarians visit feedlots in their practice an average of 1.7 times/month. Feedlot veterinarians train employees on pen riding, processing procedures, necropsy, and many other areas of cattle health and well-being. The majority of veterinarians use Beef Quality Assurance concepts as part of employee training. Veterinarians also give recommendations on routine surgical procedures, such as dehorning and castration, metaphylaxis, feed-grade antibiotics, vaccination programs, and treatment regimens. Morbidity and mortality rates for feedlots consulted were obtained, along with other information about risk factors for morbidity rates. Cattle health risk was considered the most important factor for predicting morbidity in both 2009 and 2014. This survey provides valuable information on the current recommendations of feedlot consulting veterinarians in the United States and Canada, helps track industry changes over time, and offers benchmarking data for the industry.
PregCard study: assessing the impact of routine management strategies on reproductive performance of beef herds in the upper Great Plains
Authors: Dahlen Carl R. , Stoltenow Charles L.
Published: March 2023

Summary data from pregnancy examinations were submitted by participating veterinarians over a 2-year period to assess the impacts of routine management decisions on reproductive performance in beef herds. Upon completion of pregnancy examination, the PregCard was completed by indicating the number of females evaluated, number non-pregnant, female age (cows, heifers, or both), number and age (yearling, mature, or mixed) of bulls used, breeding season dates, and whether groups were exposed to artificial insemination. Data were reported by 8 clinics and included 242,967 females in 1,782 groups. Number of females/bull and breeding season were calculated for each group. Each group was also assigned to categories for females/bull, breeding group size, breeding season length, and age class of breeding bulls. Groups consisting of only cows had greater (P less than or equal to 0.01) reported pregnancy rates compared with groups consisting of only heifers (90.1% and 86.6%, respectively). Reported pregnancy rates were also influenced (P less than or equal to 0.01) by breeding group size, breeding season length, and bull age. Females/bull decisions were impacted (P less than or equal to 0.01) by breeding system (artificial insemination or natural service), and reported pregnancy rates were impacted by a breeding system x females/bull interaction (P less than or equal to 0.001). The PregCard system provided an excellent platform to gather benchmarking data and to assess the impact of routine management practices on reported pregnancy rates in beef herds in the upper Great Plains.
Efficacy and safety of a novel DNA immunostimulant in cattle
Authors: Nickell Jason S. , Keil Daniel J. , Settje Terry L. , Lechtenberg Kelly F. , Singu Vijayakrishna , Woolums Amelia R.
Published: March 2023

Four studies were performed to evaluate efficacy (Studies 1 and 2) and safety (Studies 3 and 4) of a novel DNA immunostimulant (Zelnate, Bayer Healthcare) in cattle. Zelnate (ZEL) was administered concurrently with (Study 1) or 24 hours after (Study 2) a Mannheimia haemolytica (Mh) challenge. Holstein steers (3 to 4 months of age; n=32/treatment, Study 1; n=40/treatment, Study 2) received either ZEL or a negative control (CON) on day 0 (Study 1) or day 1 (Study 2). Calves were challenged intratracheally with 60 mL of Mh (10 to the 7th power CFUs/mL, Study 1; 10 to the 8th power CFUs/mL, Study 2) on day 0 and clinically observed to day 5. Lung scores were obtained at the time of premature death or after necropsy on day 5. ZEL mitigated lung lesions in this Mh model, compared to the CON (Studies 1 and 2), and significantly reduced mortality compared to the CON (P < 0.05; Study 2). ZEL was shown to be safe at the injection site (Study 3) and among large populations in different field scenarios (Study 4). ZEL demonstrated efficacy by mitigating lung lesions (Studies 1 and 2) and decreasing mortality (Study 2) in this Mh disease model. Studies 3 and 4 confirmed that ZEL is safe for use in cattle.
Effect of modified-live bovine viral diarrhea virus type 2 vaccine on performance, health, temperature, and behavior response in high-risk beef heifer calves
Authors: White Brad J. , Theurer Miles E. , Goehl Dan R. , Thompson Peggy E.
Published: March 2023

The objective of this study was to determine performance, health, vaginal temperature, and behavior differences in calves vaccinated upon feedlot arrival with a multivalent modified-live virus (MLV) vaccine which included bovine viral diarrhea virus (BVDV) type 2 antigen and calves vaccinated with a vaccine which did not include BVOV type 2.   Eightythree beef heifer calves were randomly assigned to receive a multivalent MLV vaccine containing either bovine herpesvirus-1, BVDV type 1, bovine respiratory syncytial virus, and parainfluenza type-3 virus (n = 42; 4-WAY), or a MLVvaccine of similar formulation which also contained a BVDV type 2 antigen (n = 41; 5-WAY). Performance outcomes were evaluated at 30 and 60 days. Vaginal temperatures were evaluated hourly and daily. Cattle behavior activity was monitored with a real-time location system. Calves in the 5-WAY group had greater average daily gain (P = 0.026) at 60 days, excluding dead animals, compared to 4-WAY group. Treatment group was not associated with vaginal temperature. Calves in 5-WAY spent a greater (P ~ 0.01) amount of time at the feed bunk on days 0, 2, 3, and 4 compared to 4-WAY. Results of this study indicate no adverse effects from administering an additional strain of BVOV type 2 to high-risk heifers. Behavioral responses indicate a potential advantage to administer 5-WAY vaccine compared to 4-WAY vaccine.