bluuebunny/crossref_metadata_2025 huggingface dataset:
Etiologic mastitis agents of high somatic cell count dairy herds in Tennessee
Authors: Roberson Jerry , Mixon Josh , Oliver Stephen , Rohrbach Barton , Holland Robert
Published: March 2023

The objective of the study was to determine etiologic agent(s) of intramammary infections (IMI) in high somatic cell count (SCC) dairies in Tennessee. This was a prospective study utilizing 2,444 dairy cows from 20 high SCC dairy herds. Composite milk samples were aseptically collected from lactating cows in 20 dairy herds with a rolling herd average SCC >400,000 cells/mL. Milk samples were cultured and mastitis pathogens identified following procedures recommended by the National Mastitis Council. The average herd percentage (average of the 20 herd averages) of culture-negative cows was 49%. The average herd percentages of positive-culture cows were 28% for coagulase-negative staphylococci (CNS), 15% for Staphylococcus aureus, 10% for environmental streptococci (ES), and ?2% for gram-negative organisms. Among cows with individual SCC >1 million cells/mL, 30% of cultures yielded Staph. aureus, 23% CNS, 26% no growth, 26% ES, and 5% gram-negative organisms. Among cows with individual SCC >400,000 cells/mL, cultures yielded 26% CNS, 30% no growth, 28% Staph. aureus, 21% ES, and 4% gram-negative organisms. Staph. aureus was the most common major pathogen, or equally common major pathogen, in 75% of high SCC herds. Environmental streptococci were the most common major pathogen, or equally common major pathogen, in 45% of high SCC herds. Staph. aureus is the major pathogen, followed by ES, among Tennessee dairy herds with high SCC. Coagulase-negative staphylococci are common, but their significance needs to be determined. Gram-negative organisms do not appear to be significant pathogens of Tennessee dairy herds with persistently high SCC.
Survey to determine relevance of online continuing education for bovine practitioners.
Authors: Thomson Daniel U. , Grooms Daniel L. , Wileman Ben W. , Twedt Kristen , Wallace Richard , Gerloff Brian , Bolton Michael , Willis Lisa , Riddell Gatz , Thomson John U.
Published: March 2023

A survey focused on distance education and online continuing education was completed by 727 bovine practitioners. All study participants were members of the American Association of Bovine Practitioners (AABP). Participants were invited through the AABP listserv. Bovine veterinarians were asked a series of demographic questions, followed by questions specific to developing an online continuing education program. The majority of the respondents (57%) had high speed or DSL internet access readily available to them, and less than 10% had dial-up internet access. Bovine practitioners indicated that they want an online continuing education system that is easy to use, provides quality presentation of relevant information, and is available 24 hours a day. Herd health, animal husbandry, and business management are topics with the highest interest by the dairy and beef-focused AABP members. The survey indicated that 37% of the AABP member respondents have attended more than one AABP annual conference in the last five years. Additionally, the survey indicated that an online system would not affect the decision of AABP members to attend the annual conference. This technology adaptation has the potential to expand member services for AABP, and deliver timely topics to practitioners in rural areas.
AABP Association News
Authors: American Association of Bovine Practioners
Published: March 2023

News and notices of interest to the bovine community.
Profitability of Preconditioning
Authors: Hilton W. Mark , Olynk Nicole J.
Published: March 2023

The objectives of this study were to assess the profitability of preconditioning calves in a commercial beef cow setting, and to determine factors associated with profit from preconditioning. The herd owner identified an overarching goal within the project: to supply a higher quality calf to the feedlot and capture the increased value of that calf to improve profitability. Results indicated that preconditioning was profitable for this example herd, with an average return to labor and management of $80.70 per calf per year for preconditioning. Returns ranged from $26.04 to $116.48 per calf per year, and profitability improved as the manager's experience with managing the preconditioning component of the operation increased. The preconditioning enterprise was profitable in each of the 11 years of the study. Factors related to profit from preconditioning included average daily gain, days-on-feed, cost of gain, and feed cost of gain. Health concerns in this example were minimal; morbidity was 0.09% (1 of 1,103) and mortality was 0.27% (3 of 1,103). Overall, returns to preconditioning were primarily due to added weight sold (63% of return to preconditioning) with the preconditioning health sales price advantage adding the remaining 37%.
Effect of trivalent modified-live virus respiratory vaccine on performance, health, and carcass traits of lightweight feeder steers
Authors: Bryant T. C. , Nichols J. R. , Rogers K. C. , Farmer T. D. , Miles D. G. , Campbell J. , Richeson J. T.
Published: March 2023

A total of 3,615 lightweight feeder steers were used to compare the effects of trivalent (infectious bovine rhinotracheitis virus and bovine viral diarrhea virus types 1 and 2) modified-live virus (MLV) vaccine products on performance, health, and carcass traits of cattle in a commercial feedlot setting. The three trivalent MLV vaccination products compared were Express? 3 (Boeh-ringer Ingelheim Vetmedica, Inc., St. Joseph MO), Bovi-Shield GOLD? IBR-BVD (Pfizer Animal Health, New York, NY), and Vista? 3 SQ (Intervet/Schering-Plough Animal Health, Summit, NJ). No differences (P?0.30) in feed conversion, final weight, or gain performance were detected among vaccination treatments. The percentage of BRD morbidity was similar (P=0.15) among treatments, averaging 12.3% overall. Furthermore, no vaccine treatment differences (P?0.36) were observed for relapse percentage, mortality or railer incidence, regardless of cause. All cattle used in the study were tested for persistent infection (PI) with BVDV, and the prevalence of cattle testing positive for PI-BVDV was similar (P=0.56) among the vaccine treatments and averaged 0.27% overall. Cattle which tested positive for PI-BVDV were not removed from the study pens, and after data were pooled, health and performance did not differ for pens with or without a PI-BVDV pen mate. When utilizing lightweight feeder steers with relatively low BRD-associated morbidity and mortality, there was no difference in performance, health, and carcass trait observations among the three trivalent MLV vaccine products evaluated.
Accuracy of a new milk strip cow-side test for diagnosis of hyperketonemia
Authors: Denis-Robichaud Jose Denis-Robichaud , DesCoteaux Luc , Dubuc Jocelyn
Published: March 2023

The objectives of this study were to determine the accuracy of the PortaBHBTM milk strip for detection of hyperketonemia in early lactation cows, and to compare the agreement of results from quarter and composite samples. A total of 577 Holstein cows of all parities, from 88 commercial herds, were sampled once during this study. Cows were sampled simultaneously for blood and milk between one and 60 days-in-milk. Blood samples were collected from coccygeal vessels, and were analyzed on-farm using an electronic ?-hydroxybutyrate (BHBA) hand-held meter. Milk samples were collected from one quarter (n=577), as well as from four quarters (composite; n=299). All milk samples were tested using PortaBHBTM milk strips (0, 50, 100, 200, and 500 æmol/L). Blood BHBA concentration was considered to be the gold standard, with hyperketonemia denned as a blood BHBA concentration ?1400 æmol/L. With this cut-point, the true prevalence of hyperketonemia in the study population was 24.6%. Using a threshold of 100 æmol/L, sensitivity and specificity of PortaBHBTM milk strips was 89.2% and 79.6%, respectively. Using a threshold of 200 æmol/L, sensitivity and specificity of PortaBHBTM milk strips was 40.3% and 99.5%, respectively. The kappa coefficient for agreement between milk results from quarter and composite samples, using a threshold of 100 æmol/L, was 0.95. Study results suggest that PortaBHBTM has good accuracy, and that there is no benefit to collect milk samples from four quarters compared with sampling one quarter.
Review of methicillin-resistant Staphylococcus aureus (MRSA) in dairy cattle
Authors: Ferreira J. Pinto , Correa M. T. , Lyman R. , Anderson K. L.
Published: March 2023

Methicillin-resistant Staphylococcus aureus (MRSA) has emerged globally as a significant public health/antimicrobial resistance nosocomial problem, both in human and veterinary medicine. In recent years, the so-called livestock-associated MRSA has become an additional focus. A literature review indicates few reports of MRSA in dairy cattle. Work from our laboratory supports previous studies indicating that MRSA is rare in milk of dairy cattle in the United States. Recent and sporadic isolation of MRSA and related staphylococci from cattle in countries other than the United States, and the similarity between some of the human and animal isolates found, provide rationale for monitoring MRSA occurrence in cattle. Considering the importance of S. aureus in human infectious disease, its highly contagious behavior among dairy cows, and the current gaps in knowledge about potential human-bovine connections, the epidemiology of MRSA (and other staphylococci) should represent an area of attention by the scientific community.
Case report
Authors: Thomson Daniel U. , Moore Eric S. , White Brad J. , Reinhardt Chris D.
Published: March 2023

A total of 202 Angus steers with an average body weight (BW) of 678ñ73 lb (308ñ33.2 kg) were used to evaluate the effects of undifferentiated bovine respiratory disease (BRD) on feedlot performance and carcass quality in cattle marketed at a common yield grade end-point. Calves were fed in a single pen in a commercial feedyard. Individual weights were collected on arrival, at 75 days on feed, and immediately prior to shipment at time of harvest. Cattle were harvested in three different groups based on day 75 BW and ultrasound evaluation: 122, 156, or 178 days on feed. Cattle treated two or more times weighed less upon feedlot arrival, had greater mortality, lower average daily gain (ADG), lower day 75 BW, and less external fat deposition on day 75 than cattle not requiring treatment for BRD (P less than 0.05). Overall ADG was lower for cattle requiring either one or two or more treatments compared to cattle requiring no treatments; however, ADG from day 75 through harvest was similar among cattle requiring zero, one, and two or more treatments. There was no effect of BRD treatment on hot carcass weight, carcass quality, or yield grade (P less than 0.05). Lengthening the feeding period to attain a comparable body composition for cattle that were treated for BRD, compared to cattle never treated for BRD, resulted in similar quality grades.
Caseous lymphadenitis
Authors: Simpson Katharine M. , Washburn Kevin E.
Published: March 2023

Caseous lymphadenitis, caused by the bacterium Corynebacterium pseudotuberculosis, is of importance to small ruminant producers worldwide. The chronic persistent nature of the disease process makes it challenging to effectively treat or control once endemic in a herd or flock. This article discusses the recent advances and time-honored methods utilized in the management of caseous lymphadenitis in sheep and goats, as well as the associated advantages and disadvantages of each.
Outbreak of bovine stomatitis in a feedlot due to Setaria lutescens (yellow foxtail)
Authors: Campbell John R. , Jelinski Murray D. , Petreny Joe , Jones Corey , Perry Allen
Published: March 2023

A case of poor-doing cattle in a feedlot in the prairie region of western Canada was investigated. Clinical examination revealed mild to severe chronic ulcerative stomatitis. Histopathological examination confirmed plant material embedded within the lesions. Yellow foxtail (Setaria lutescens) was grossly visible in clover silage fed to the cattle. This case highlights the need to consider plant awns as a potential cause of outbreaks of ulcerative stomatitis.
AABP Conference (2012): Receptions
Authors: Bovine Practitioners American Association of
Published: March 2023

Description of the 45th American Association of Bovine Practitioners Conference, 2012.
Vaccine associated mucosal disease case study
Authors: Miller Myrna M. , O'Toole Donal , Cavender Jacqueline L. , Cornish Todd E. , Dawson Timothy G. , Smylie J. Maxwell , Fox Jonathan H. , Hill Kevin L. , Montgomery Donald L. , Vazquez Marce , Schumaker Brant A.
Published: March 2023

Mucosal disease (MD) affected a single-source group of 461 recently purchased yearling steers shortly after vaccination with a multivalent vaccine containing 2 strains of modified-live bovine viral diarrhea virus (BVDV). Terminal disease affected 21 steers at 18 to 66 days post-vaccination, and was confirmed as mucosal disease in 3 carcasses examined postmortem. An additional 17 animals identified as persistently infected remained asymptomatic during the study A laboratory study was undertaken to determine whether mucosal disease was triggered by a BVDV in the multivalent vaccine. Purified cytopathic BVDV isolates from 2 animals that died early in the outbreak were genetically identical (>99%) to the vaccine type 2 BVDV strain 125a in 3 genomic regions: 5â²-untranslated region to the Npro, E2, and NS2/3. This genetic identity combined with the presence of a single peak outbreak occurring soon after vaccination suggests that the vaccine BVDV was the cause of mucosal disease in these steers. The investigation underscores laboratory challenges in determining the role of vaccinal BVDV when mucosal disease affects multiple animals within 2 months of vaccination, and the need for laboratory testing to identify all persistently infected animals.
Effects of administration of a modified-live virus respiratory vaccine and timing of vaccination on health and performance of high-risk beef stocker calves
Authors: Richeson J. T. , Beck P. A. , Poe K. D. , Gadberry M. S. , Hess T. W. , Hubbell D. S.
Published: March 2023

A randomized, controlled field study was conducted to evaluate the efficiency of various management regimens using a pentavalent modified-live virus (MLV) respiratory vaccine containing bovine herpesvirus-1, bovine viral diarrhea virus types 1 and 2, parainfluenza-3 virus, and bovine respiratory syncytial virus. Crossbred beef calves (n=370) weighing 466 +/- 5.5 lb (212 +/- 2.5 kg) were acquired from auction markets. Calves were stratified by castrate status on arrival and assigned randomly to 1 of 3 experimental treatments: (1) initial MLV vaccine on day 0 (AMLV), (2) initial MLV vaccine on day 14 (DMLV), or (3) no vaccination with MLV vaccine until the end of the 42-day receiving period (NMLV). Least-squares means were evaluated using the contrasts: (1) vaccinated (VAC) vs NMLV, and (2) AMLV vs DMLV. Body weight was recorded on days 0, 14, 28, 42, and at the end of the grazing period, and health was monitored daily. Average daily gain was greater for DMLV vs AMLV from days 14 to 28 (P less than 0.01), and VAC vs NMLV from days 28 to 42 (P=0.04). However, performance was not different (P greater than or equal to 0.16) between VAC and NMLV from days 0 to 42. The overall incidence of clinical bovine respiratory disease did not differ (P greater than or equal to 0.82); however, there was a tendency (P=0.08) for increased relapse rate in NMLV calves compared to VAC. Results suggest that MLV vaccine administered to high-risk stacker calves on day 0 or 14 may reduce relapse rate; whereas, gain was reduced transiently when MLV vaccine was administered at day 0.
Case report
Authors: Ferro Pamela J. , Fearneyhough Malcomb G. , Calvert Clint , Neill John D. , Ridpath Julia F.
Published: March 2023

Bovine viral diarrhea virus continues to have significant economic impact on the cattle industry worldwide. The virus is primarily maintained in the cattle population due to persistently infected (PI) animals. Herd surveillance, along with good vaccination programs and biosecurity practices, are the best way to mitigate losses and production of PI animals. Two PI calves were identified in a semi-closed beef herd with excellent management practices, highlighting the continued significance and persistence of this virus in the cattle population.
Survey to describe beef producer opinions on antibiotic use and consumer perceptions of antibiotics in the beef industry
Authors: Lee T. L. , Thomson D. U.
Published: March 2023

Beef producers and veterinarians work together to improve cattle health and well-being. Antibiotic use and resistance is of interest to all involved in the beef industry, including beef consumers. A 26-question survey was developed by veterinarians at Kansas State University to explore antibiotic use and opinions on contemporary issues at the beef producer level. The survey was advertised throughout the United States and Canada via popular industry outlets. A total of 260 surveys were completed by beef producers from 43 states and 1 province in Canada. Beef producers operating cow-calf operations represented 88% of the respondents. Producers managing stocker, backgrounder, and feeder operations were represented in equal proportions in the remaining survey responses. Eighty-five percent (85%) of beef producers indicated they use the services of a veterinarian regularly, while only 23% reported that they have a written, documented, and signed veterinary-client-patient relationship. Participants indicated that they rarely use oral and injectable antibiotics. The most common indication for antibiotic use in cattle managed by respondents was for the treatment of bovine respiratory disease, foot rot, and pinkeye. Seventy-two percent (72%) of producers indicated that Beef Quality Assurance is an important industry program for addressing antibiotic use and prevention of antibiotic residues. When asked if familiar with the Veterinary Feed Directive rule, 81% of respondents indicated they had knowledge of the law. These data illustrate that beef producers are willing to share information about their production systems and management strategies, including information on antibiotic use in cattle.
Alternative ingredients in calf milk replacer
Authors: Thornsberry R. M. , Wood David , Kertz A. F. , Hutcheson David
Published: March 2023

Non-dairy source ingredients for calf milk replacer formulations have been evaluated in North America and Europe, and are routinely used in European milk replacer formulas. Dairy origin ingredients are increasingly less economical for use in animal feed due to increased global demand for these high-quality foodstuffs. As an alternative, specific non-dairy ingredients are satisfactory for neonatal calf diets when properly incorporated into calf milk replacers. Plant-sourced proteins and oils must be properly processed for efficient utilization. Feeding spray-dried bovine plasma results in calf performance comparable to feeding milk protein when incorporated at recommended levels in calf milk replacers, and it reduces calf morbidity and mortality. Replacing milk lactose is more problematic because pre-ruminant calves lack intestinal enzymatic activity to digest plant-based polysaccharides. The objective of this review is to provide cattle veterinarians detailed information about alternative ingredients that are acceptable for formulation into calf milk replacers.
Case report
Authors: Beidel Curtis R. , Kristula Michaela A. , Aceto Helen W. , Smith Billy I.
Published: March 2023

Calves fed milk infected with Mycoplasma bovis are at risk of developing mycoplasma-associated diseases such as pneumonia, otitis media, and arthritis. This study was conducted to determine if acidification of milk cultured positive for M. bovis would consistently result in complete elimination of the organism. Three consecutive daily milk samples were obtained from 8 cows with confirmed M. bovis mastitis. An aliquot of each milk sample was submitted for culture and enumeration of M. bovis as colony-forming units per milliliter (cfu/mL). Dilute (9.8%) formic acid was used to acidify the remainder of each sample, after which culture and enumeration of M. bovis was repeated. Prior to acidification, M. bovis was detected in all milk samples, but the levels present were highly variable both between cows on a given day and within cow between days. On day 1, the median was 418 cfu/mL of M. bovis (interquartile range (IQR) 25th and 75th percentile (125 to 1,445; range 15 to 3,640 cfu/mL)). Equivalent results for day 2 were median 155 cfu/mL (IQR 30 to 1,330; range 20 to 2,280 cfu/mL), whereas day 3M. bovis levels were median 35 cfu/mL (IQR 27 to 230; range 15 to 440 cfu/mL). Each of the samples collected on days 1 to 3 was culture negative for M. bovis following acidification. Results from the current study demonstrate that formic acid is effective for consistently eliminating M. bovis from culture-positive milk.
Description and justification of a consistent technique for euthanasia of bovines using firearm and penetrating captive bolt
Authors: Dewell Reneé D. , Dewell Grant A. , Bear Douglas A. , Weber Wolfgang , Griffin D. Dee , Rowe Eric W.
Published: March 2023

Firearms and penetrating captive-bolt devices are commonly used to euthanize cattle of all ages, and result in rapid unconsciousness and death due to lethal brain damage when properly conducted. Several reports have described methods to determine the appropriate point of entry when using firearms or penetrating captive bolts for bovine euthanasia. However, some previously described techniques to determine the point of entry may be difficult to remember, necessitate multiple steps to ascertain the point of entry, require adjustment based on breed type, and/or may be challenging in polled cattle if the suggested protocol uses horn anatomy as part of the guidance. A simple, reliable description for an appropriate point of entry and trajectory course for a firearm or captive bolt is to direct the trajectory perpendicular or slightly downward to the frontal sinus plane on midline between the base of the ears at the level of the external acoustic meatus. The orientation of the brainstem and ear is not altered by variables considered in some other protocols. The objective of this report is to describe and justify an uncomplicated, repeatable protocol to consistently determine an appropriate point of entry and line of trajectory for firearm or penetrating captive-bolt euthanasia of domestic bovines across a variety of breeds, ages, skull types, and polled or horned cattle, thus increasing the likelihood that the procedure will be conducted quickly and humanely with minimal stress to the handler and the animal.
AABP Conference (2016): President's Reception
Authors: Bovine Practitioners American Association of
Published: March 2023

Description of the 2016 American Association of Bovine Practitioners Conference.
Comparison of meat quality characteristics, growth, and feed efficiency of intact and castrated post-pubertal bovine males
Authors: Thomson D. U. , Youngers M. E. , Schwandt E. F. , Bartle S. J. , Siemens M. G. , Reinhardt C. D.
Published: March 2023

Yearling Red Angus or Black Angus bulls (n = 24; initial BW = 1,336 ± 25.1 lb; (606 ± 11.4 kg); average 16 mo of age) were used to evaluate the effects of castration and use of growth promoting technology (STR) on performance, carcass traits, and meat quality characteristics when compared to intact (BULL) post-pubertal male cattle. The STR treatment included administration of a combination 120 mg trenbolone acetate + 24 mg estradiol growth-promoting implant on d 0 and feeding ractopamine hydrochloride the last 28 d on feed. Cattle were individually fed a corn-based finishing diet for 62 d and harvested at a commercial abattoir. Intact bulls had greater average daily gain (4.08 vs 3.19 lb or 1.85 vs 1.45 kg/d; P = 0.02) and feed:gain ratio (8.54 vs 10.97; P = 0.02) than STR. There were no treatment differences for dry-matter intake, quality or yield grade, hot carcass weight, back-fat thickness, or dressing percent (P < 0.05). Longissimus muscle area was greater in BULL compared to STR carcasses (16.6 vs 15.0 in2 or 106.9 vs 96.8 cm2; P < 0.01). Warner-Bratzler Shear Force was not affected (P > 0.05) by treatment. Intact bulls had improved performance with no differences in carcass characteristics, tenderness, or sensory panel measurements compared to STR treatment.
Pilot study
Authors: Patel K. E. , Godden S. M. , Royster E. E. , Timmerman J. A. , Crooker B. A. , McDonald N. E.
Published: March 2023

The study objective was to evaluate the effects of applying a culture-guided, quarter-level selective dry cow therapy (SDCT) program on udder health and antibiotic usage as compared to blanket dry cow therapy (BDCT). Two days prior to dry-off (DO), 56 cows were randomly assigned to a BDCT or SDCT group and aseptic quarter milk samples were collected for laboratory culture. For cows in the SDCT group, milk from each quarter was also cultured using a rapid culture system, with results recorded as bacterial "growth" or "no growth". On the day of DO, cows in the BDCT group were infused with an antibiotic and an internal teat sealant in all 4 quarters. For cows assigned to the SDCT group, quarters with bacterial growth were infused with an antibiotic plus internal teat sealant, while quarters with no growth were infused with internal teat sealant only. Quarter milk samples were collected days 1 through 7 after calving for laboratory culture, and clinical mastitis events were recorded between DO and 30 days-in-milk. Logistic regression was used to evaluate the effect of treatment on measures of udder health after calving. Results showed no effect of treatment on quarter level risk for presence of infection after calving ( 42.1 % vs 39.6%), cures (82.3% vs 88.0%), or new infection ( 41.5% vs 40.2%) for the SDCT and BDCT group, respectively. Antibiotic use was reduced by 48% in the SDCT group. Results of this pilot study suggest that a culture-guided quarter-level SDCT program can achieve equal udder health compared to BDCT, while significantly reducing antibiotic use at DO.
Evaluation and validation of a paralumbar fossa transabdominal rumen fluid sampling technique
Authors: Roberson Jerry R. , French Hilari E. , Robinson James Q.
Published: March 2023

A simple method to obtain rumen fluid via the left paralumbar fossa was evaluated on 58 adult cattle. Using a 16-gauge 1.5 inch (3.8 cm) needle, rumen fluid was successfully collected and evaluated from 45 of 58 head (78%). The primary reason for failure was body wall thickness exceeding the 1.5 inch (3.8 cm) needle (P = 0.0002). Average rumen pH of the 45 cattle samples was 7.9; the test cattle were primarily fed guinea grass with occasional brewer's grain supplement. An average 3 protozoa per field under 40 x magnification were seen. No external hematomas or other swellings were seen during the 3-week follow-up observations, and no complications were noted. Eleven of the 58 cattle (19%) had increased body wall thickness, based on ultrasonographic follow-up. The average length of time required to obtain a rumen sample, measured by introduction of the needle to the withdrawal of the needle, was 3 seconds (range< 1 to 8 sec). We conclude that the left paralumbar fossa trans-abdominal rumen fluid sampling technique is a safe and efficient method to obtain rumen fluid in cattle with a moderately thin (~ 30 mm) body wall.
Prevalence and associated factors of injury in bovine practitioners in the United States and Canada
Authors: Sander William E. , Raizman Eran A. , Humphrey C. Scott , Johnson April J.
Published: March 2023

A cross-sectional online survey was administered to American Association of Bovine Practitioner members to determine the prevalence of injuries to veterinarians due to performing rectal palpation or other common work-related injuries among bovine practitioners. Basic demographic information was collected on veterinarians related to their time in practice, gender, physical attributes that may be risk factors for injury, characteristics of their practices, and geographic information. From the surveys, 1158 responses were analyzed. Seventy-seven percent of respondents experienced pain while rectally palpating cattle, of which 42% reported severe pain. Multiple locations were reported as the source of pain (80% arm/elbow, 70% shoulder). Fifty-two percent reported that pain limited performance slightly, and 7% moderately or severely. On average, pain started 12 years after beginning practice. Years in practice, herd size, and changing palpating arm due to pain were associated with experiencing pain. Surgical treatment of the practitioner was positively correlated with increasing age, a higher average number of beef herds visited daily, increased average number of palpations daily, the use of a stall for palpation, use of analgesia, and predominantly using the left hand. Pain for practitioners during bovine rectal palpation is a common occurrence. Veterinary students as well as practitioners should be educated about ways to mitigate these potential occupational hazards, and further research should be conducted on how practices can be modified to reduce these outcomes.
What dairy veterinarians should know about bovine leukemia virus
Authors: Barlett Paul C. , LaDronka Rebecca M. , Ruggiero Vickie J. , Hutchinson Holden M.
Published: March 2023

Bovine leukemia virus (BLV) is now present in almost all US dairy herds, and the prevalence among cattle in our milking herds is now approaching 50%. Most dairy producers know that BLV can cause tumors in a small percentage of cattle, but the associations now being observed with reduced milk production and cow longevity are not yet appreciated by most dairy producers. Over 20 nations have eradicated BLV from their cattle populations by removing all antibody positive animals. This is economically impossible for all but a small percentage of farms that have very low BLV prevalence. Management interventions to reduce transmission have not been promising. New diagnostic methods may be helpful to better target culling and segregation to those animals that are most infectious to herd mates. Producers interested in determining BLV prevalence in their herd are advised to conduct a BLV herd profile, which involves milk or serum ELISA testing of the 10 most recently calved cattle in lactations 1, 2, 3, and 4+. More information is available on our website at www.BLVUSA.com.
Comparison of three vaccine programs on the health, growth performance, and carcass characteristics of high-risk feedlot heifers procured from auction-markets
Authors: Hagenmaier Jacob A. , Terhaar Brett L. , Blue Ken , Hoffman Bruce W. , Fox J. Trent , Theurer Miles E.
Published: March 2023

A total of 2,575 beef heifers (BW = 568 ± 28.1 lb; 258 ± 12.7 kg) at high-risk of developing bovine respiratory disease (BRD) were enrolled in a randomized complete-block design study at a commercial feedlot to evaluate the effect of 3 vaccine programs on health, growth performance, and carcass characteristics. Dates of arrival to the feedyard served as the blocking factor and 10, 3-pen blocks were enrolled in the study (n = 10 replications per vaccine program). Chute- order randomization was used during arrival processing to assign heifers to 1 of 3 vaccine programs that differed by vaccine products or timing of the pentavalent modified-live viral vaccination: 1) Pyramid® 5 and Presponse® SQ during arrival processing (PRE), 2) Titanium® 5 and Nuplura® PH during arrival processing (TNA), and 3) Nuplura® PH during arrival processing with Titanium® 5 delayed until 28 days- on-feed (TND). No booster vaccinations were administered. Overall mortality, BRD morbidity, and BRD treatment success risks did not differ among the vaccine programs (P>0.13). There were numerically fewer mortalities attributable to acute interstitial pneumonia in TNA heifers than the TND and PRE heifers (probability of difference = 0.99 and 1.00, respectively). Mortality attributable to BRD did not differ between vaccine programs (probability of difference < 0.48). Endotoxin concentrations were measured in the Mannheimia haemolytica vaccines, and were lower in Nuplura® PH than Presponse® SQ. An arrival vaccine program implementing Titanium® 5 and Nuplura® PH had similar efficacy on BRD- related health outcomes as vaccinating with Pyramid® 5 and Presponse® SQ. Delaying a pentavalent viral vaccine until 28 days-on-feed did not affect health or growth-performance outcomes in this study.
Case series
Authors: Furman Thomas J. , Grotelueschen Dale M. , Knudsen Durt , Furman Jim , Furman Seophanie , Griffin D. Dee , Theurer Miles E.
Published: March 2023

Laryngeal diphtheria is a contributor to morbidity and mortality in feedlot cattle. Medical treatment has resulted in great success; however, advanced cases often do not successfully respond to systemic antimicrobials. The purpose of this report is to describe a surgical procedure performed in field settings on feedlot calves with diphtheria that failed to respond to medical treatment. Forty-five medically nonresponding clinical diphtheria cases were selected for surgery. The calves were restrained in a chute, surgically prepped, and local anesthesia was administered. A surgical incision through the skin, subcutaneous tissues, and a transverse incision between tracheal rings was performed. A tracheostomy tube was placed inside the tracheal incision to provide a patent airway. A total of 42 surgical cases (93%) with diphtheria completed the balance of the feeding period to harvest. Complications including obstruction due to organic material and loss of tube were managed successfully when identified early. Surgical treatment of calves failing to respond to medical therapy in feedlot cattle provides a practical option to perform in field settings with minimal risk for complications. While the incidence of non-responding diphtheria cases is small, surgical treatment of calves failing to respond to medical therapy provides an option to impact mortality of the affected population and allow preservation of resources.
Case report
Authors: Kleinhenz Michael D. , Ydstie Joshua A. , Gorden Patrick
Published: March 2023

Mastitis caused by Klebsiella spp is an emerging issue associated with contaminated environments, often with poor response to therapy. This case report highlights 42 cows with 50 cases of clinical mastitis caused by Klebsiella spp. Eight cases of clinical mastitis were from 4 cows with repeat cases. The mean days-in-milk (DIM) at diagnosis was 135; 38% of cows were within the first 100 DIM. Cows diagnosed with mastitis had a 65% decrease in milk production. Severity scores assigned to each case were 24% mild, 33% moderate, and 43% severe. The majority of cows were either culled (38%) or euthanized (19%) as a result of the mastitis. Many of the cows that developed clinical mastitis had been good producing animals with low somatic cell counts prior to the case. Environmental control and cow hygiene are key to prevention of mastitis.
Multiple bovine abortions with evidence of fetal locoism from pre-clinically intoxicated dams
Authors: Betley Michael J. , Stegelmeier Bryan L. , Niles Gene , Frank Chad B.
Published: March 2023

Chronic consumption of specific plant species from the genera Oxytropis, Astragalus, lpomeoa, and Swainsonia, commonly known as locoweeds, is well known to induce locoism in grazing animals. Locoism in cattle is characterized by sensory deficits, ataxia, behavior changes, loss of condition, and failure to grow. The toxic principle swainsonine is rapidly absorbed and distributed through the bloodstream to multiple organs where it inhibits cellular lysosomal alphamannosidase and Golgi mannosidase II, leading to lysosomal dysfunction and disruption of glycoprotein processing. Excessive mannose-rich oligosaccharide accumulations cause cytoplasmic vacuolation and cellular dysfunction. In addition to neurologic disease, chronic consumption of locoweeds is known to induce abortion and embryonic death in neurologically affected dams. We describe multiple cases of bovine abortion associated with chronic locoweed ingestion in non-clinical dams from a herd in southeastern Colorado. Neurons from the cerebral cortex, brainstem, cerebellum, and renal tubular epithelial cells displayed the characteristic cytoplasmic vacuolation observed in adult cases of locoism in the aborted animals. Although chronic ingestion of locoweed is widely known to cause early gestation embryonic death, late-term hydrops amnii, and fetal fluid accumulation, locoweed-induced abortion should be considered as a differential diagnosis for cases ofnon-infectious abortion in grazing cattle, even in the absence of maternal clinical signs. These findings indicate that the bovine fetus may be more sensitive to the abortive effects of swainsonine than previously thought.
Explaining earnings variation of bovine veterinarians in private practice
Authors: Dodge Lynn E. , Koontz Stephen R.
Published: March 2023

Bovine veterinarians are needed to protect food animal protein supplies, prevent losses due to disease, and protect public health: society needs these services. It is also important that economic incentives exist for, and are understood by, practitioners that serve the food animal industry. Surveys of American Association of Bovine Practitioners members were examined to explain variation in bovine veterinary earnings in private practice. We estimate the systematic variation in earnings due to practitioner characteristics.  Results communicate expected earnings levels and variation across bovine veterinarians in private practice based on observable individual attributes and characteristics. These results communicate, in context of the survey questions, what the market for bovine veterinary services values. Bovine veterinarians are compensated more for specializing in a species within the food animal industries and owning their practice. The volume of animals seen is important, and bovine veterinarians should look to practice in areas with large concentrations of animals. Numbers of clients attained are not important, whereas numbers of animals serviced are. Further, gaining experience is more important than additional education or certifications beyond the doctor of veterinary medicine degree. However, there remains a large unexplainable variation in earnings models. This unexplained variation is likely due to unobserved and unmeasured ability/effort effects within each individual and it is thought, but not tested, that higher quality veterinarians earn more. Future salary surveys need to attempt to measure these deep human capital attributes.
Efficacy of a combination modified-live IBR-BVD-PI3- BRSV vaccine + Mannheimia haemolytica toxoid against challenge with virulent bovine respiratory syncytial virus (BRSV) in young calves 60 days of age
Authors: Masic Aleksandar , Sobecki Brian , Mahan Suman , Brice Chadwick , Mattern Sally , Meinert Todd , Correas Ignacio , Moulin Véronique , Ellis John
Published: March 2023

Efficacy of attenuated (att) bovine respiratory syncytial virus (attBRSV) as an antigen fraction in a multivalent 6-way vaccine containing modified-live virus and an inactivated Mannheimia haemolytica bacterin-toxoid was given as a single subcutaneous injection, and evaluated by an aerosol challenge by nebulization in young calves with virulent BRSV strain 21 d after vaccination. A total of 32 Holstein calves, seronegative to BRSV and 60 days-of-age at the time of vaccination, were used in the study. Calves were allocated to 2 treatment groups with 16 animals per group, and received either a single dose of a modified-live bovine herpes virus-1, bovine viral diarrhea virus, parainfluenza 3 virus, bovine respiratory syncytial virus vaccine + M. haemolytica bacterin-toxoid, or corresponding placebo formulation without targeted BRSV antigen. Administration of the 6-way vaccine containing BRSV fraction induced significantly higher virus-neutralizing antibody (p=0.0003) and anti-BRSV IgG titers (p=0.0006) in vaccinated animals compared to the placebo group. Consequently, BRSV-vaccinated calves had significantly (p<0.0001) higher arterial partial pressures of oxygen (PaO2), significantly (p<0.0001) lower percentage of lung lesions, and significantly reduced mortality rate (p<0.0001) than did placebo vaccinated calves subsequent to BRSV challenge. Furthermore, there was a 61.2% reduction in virus shedding and duration of shedding (p<0.0001), indicating strong vaccine efficacy.
Topical salicylic acid treatment of digital dermatitis in dairy cows
Authors: Wirt Kelsey M. , Young Jennifer M. , Cramer Gerard , Wagner Sarah A.
Published: March 2023

Salicylic acid (SA) provides similar treatment efficacy to tetracycline-class antibiotic drugs for the treatment of digital dermatitis (DD) in dairy cows. No milk withholding time following SA treatment has been established in the United States. The objective of this study was to generate data about drug residues in milk following topical treatment of DD lesions with SA. Cows with active (M2 stage) DD lesions were assigned to 1 of 3 treatments: salicylic acid paste, salicylic acid powder, or tetracycline powder. Lesions were photographed digitally and thermographically and scored using the M-stage scoring system before treatment and at 7 and 28 d post-treatment. Milk samples were collected before treatment and at 4 h, 8 h, 24 h, 36 h, and 48 h afterward. Most cows did not have detectable salicylic acid in their milk more than 24 hours after treatment; however, 3 cows had detectable levels of SA at 36 hours post treatment. Treatments did not differ in their effects on DD lesions. These data suggest that milk from treated cows should not be used or sold for at least 48 hours following the topical treatment of DD lesions with salicylic acid.
Evaluating the environmental survivability of Mannheimia haemolytica on various potential fomites
Authors: Ruffin Robert P. , Lawhon Sara D. , Lubbers Brian V. , Capik Sarah F.
Published: March 2023

Bovine respiratory disease (BRD) is an important cause of morbidity and mortality in beef and dairy cattle in North America. Of the significant bacteria implicated in BRD cases, Mannheimia haemolytica is the most common microbe isolated in clinical cases, yet little is known about its environmental survivability. The objective of this study was to examine relative survivability of M. haemolytica on metal, wood, and plastic under varying environmental conditions. Microenvironments were constructed at approximately 37℉ (3℃), 71℉ (22℃), and 97℉ (36℃) using plastic containers and monitored for temperature and humidity. Stainless steel, polypropylene, and wood spheres were inoculated with M. haemolytica, placed in each microenvironment, and cultured for viable bacteria at 0, 2, 6, 24, and 48 h after inoculation. Presence or absence of growth of M. haemolytica was confirmed by MALDI-TOF mass spectrometry. Both wood and plastic materials supported the recovery of viable bacteria for a much longer duration than stainless steel. Additionally, increased temperature and decreased humidity lowered bacterial viability. These results demonstrate that both material and environment are factors related to M. haemolytica survival, which has potential biosecurity implications when managing BRD in beef and dairy operations.
Systematic review of vaccine efficacy against Mannheimia haemolytica, Pasteurella multocida, and Histophilus somni in North American cattle
Authors: Capik Sarah F. , Moberly Heather K. , Larson Robert L.
Published: March 2023

Bovine respiratory disease (BRD) continues to greatly affect beef, dairy, and veal production systems. Vaccination against the bacteria involved is common, yet questions remain regarding efficacy. The purpose of this review was to evaluate the evidence for effects of vaccinating United States or Canadian beef, dairy, or veal calves for Mannheimia haemolytica, Pasteurella multocida, or Histophilus somni on BRD-related morbidity, mortality, or postmortem lung lesions. Comprehensive searches were performed of MEDLINE, EMBASE, and CAB Abstracts via OVID. The Bovine Practitioner and references of relevant systematic reviews were searched by hand. Major commercial vaccine producers were queried for additional product information. Peer-reviewed, published after 1979, full text available in English, performed in the US/Canada, control group included, sufficient evidence of randomization/blinding, and correct statistical methods were essential criteria for inclusion in the review. Five studies met the criteria. Of them, 1 investigated a H. somni and M. haemolytica vaccine in feeder calves, 1 studied M. haemolytica vaccination in feeder calves, 1 evaluated a different commercially available M. haemolytica vaccine and 1 experimental M. haemolytica vaccine in young Holstein calves, and 1 investigated multiple vaccines for P. multocida or M. haemolytica or combinations thereof in nursing beef calves. There are too few repeated studies on comparable populations to support further analysis of BRD bacterial vaccine efficacy in North American cattle.
evaluation of arrival metaphylaxis with enrofloxacin compared to tulathromycin in feedlot cattle at high risk of developing bovine respiratory disease in Mexico
Authors: Burciaga-Robles Luis O. , McMullen Christopher , Bras Ana , Guerra-Maupome Mariana , Nava-Gaspar Rodolof A. , Rademacher Ryan D. , Hannon Sherry J. , Mercado-Talamantes Victor E. , Booker Calvin W.
Published: March 2023

In this large-pen commercial field trial, mixed beef-breed bulls and heifers were randomly allocated at feedlot arrival to 1 of 2 experimental groups: ENRO or TULA. Animals in the ENRO group (10 multi-pen lots; 2037 animals) received a subcutaneous injection of enrofloxacin at a dosage of 3.4 mg/lb (7.5 mg/kg) body weight once at allocation. Animals in the TULA group (10 multi-pen lots; 2036 animals) received a subcutaneous in­jection of tulathromycin at a dosage of 1.1 mg/lb (2.5 mg/kg) body weight once at allocation. Study animals were housed by experimental group in commercial feedlot pens and fol­lowed from allocation until slaughter. There were no statisti­cal differences detected in any of the animal health or feedlot performance outcome variables between the experimental groups at the P < 0.050 level. Given the lack of detectable sta­tistical differences in animal health and feedlot performance outcome variables in the current study, the relative cost effec­tiveness of metaphylaxis programs utilizing enrofloxacin or tulathromycin in mixed beef-breed bulls and heifers at high risk of developing bovine respiratory disease should be depen­dent on the relative cost of each program, as well as any intan­gible attributes such as syringability, storage requirements, potential for antimicrobial resistance, etc.
Comparison of the effect of different management strategies on the quality of recycled sand used for bedding in free stalls in southeastern Pennsylvania
Authors: Egolf Emily A. , Kristula Michaela A. , Stefanovski Darko
Published: March 2023

The effect of different management strategies on dry matter (DM), organic matter (OM) and bacterial populations in newly recycled sand (RS) were compared on three commercial dairy farms in southeastern Pennsylvania during late spring and summer. DM increased by 0.98%, OM decreased by 0.05%, and bacterial numbers were not different comparing arranging RS into one windrow and turning 3 times to forming a static pile. RS stored outside had fewer coliform bacteria compared to when stored inside under cover. RS should be stored for a minimum of 22 days before placement back into the cow stalls to minimize the numbers of bacteria associated with mastitis.