bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of the Analgesic Effect of Clonidine and Lidocaine When Administered Epidurally in Cattle
Authors: Lin Hui-Chu , Heath Allen M. , Pugh David G. , Trachte Elizabeth A.
Published: March 2023

This study was conducted to compare clonidine and saline to lidocaine for epidural analgesia in cows. Four adult mixed-breed beef cattle weighing 1241±268 lb (564 ± 122 kg) were used. Each cow was randomly assigned to receive each of the three treatments, with a 1-week interval between each treatment. Treatments included epidural administration of 1) 5 ml of physiological saline (0.9% NaCl) solution, 2) 0.2 mg of lidocaine/kg of body weight, not to exceed 100 mg (5 ml), and 3) 5 pg of clonidine/kg, diluted with 0.9% NaCl to provide a volume of 5 ml. The site of epidural injection was the first or second caudal intervertebral space. Heart rate, respiratory rate and arterial blood pressure were recorded before injection; at 5, 10, 20 and 30 minutes after injection; and at 15-minute intervals thereafter. Onset and duration of analgesia, sedation and ataxia were recorded. Analgesia was evaluated by the response to an electrical stimulus and to a needle prick. Repeated-measures ANOVA was used to detect differences between treatments.Lidocaine-induced analgesia occurred within 10 ± 7 minutes and lasted 56.3 ± 40.1 minutes. Analgesia induced with clonidine occurred within 34 ± 11 minutes and lasted at least 6 hours when tested with electrical stimulus, and 11.6 hrs (699 ± 178 minutes) when tested with needle prick. Epidurally administered 0.9% NaCl solution did not induce analgesia. Heart rate decreased significantly at 45 minutes and 30 minutes following epidural administration of lidocaine and clonidine, respectively. Slight to mild sedation and ataxia were observed in three cows, and one cow showed moderate sedation and ataxia following epidural administration of clonidine. Increased salivation and frequency of urination were observed in each cow treated with clonidine.
Cystic ovarian follicles in cattle
Authors: Talafha Abdelsalam Q. , Bahi Ismail Zuhair A. , Peter Augustine T.
Published: March 2023

Cystic ovarian follicles are considered as important causes of reproductive failure in cattle. The economic loss it causes in the dairy industry is mainly due to increases in days open in the postpartum period, and subsequent increases in culling rate. The disease process is a consequence of a mature ovarian follicle that fails to ovulate at the appointed time in the oestrous cycle. Recent studies suggest that this anovulatory ovarian follicular structure may persist as a dominant structure, preventing further follicular growth. Alternatively, it may be replaced by another cystic follicle or it may regress, allowing initiation of a follicular wave followed by the development of a dominant follicle and ovulation. In certain cases, these cystic follicular structures are luteinized and secrete progesterone. Our understanding of the aetiology and treatment for cystic ovarian follicle is incomplete at this time. However, it is critical to consider the hypotheses developed in recent years. Past findings suggested that perturbation of the hypothalamo-hypophyseal-ovarian (HHO) axis, due to many exogenous and endogenous factors, caused anovulation. One such major perturbation may be aberrant changes in the receptor expression in the HHO axis for the hormones involved in maturation, deviation, dominance, and ovulation of the follicle. Besides the receptors, conditions such as insensitivity of the hypothalamus to the positive feedback effect of estradiol may have a role in the aetiology. Based on studies with experimentally induced and naturally occurring cystic ovarian follicles, insufficient, inadequate, and inappropriate timing of luteinizing hormone (LH) release and levels around the time of ovulation have been suggested as the major causes for ovulation failure. However, not all studies support this hypothesis. Hitherto, hormonal preparations that release LH from the anterior pituitary, or that have LH-like action, are used to treat cysts. Gonadotropin releasing hormone (GnRH) fits the former category, and human chorionic hormone (hCG) the latter group. However, recent studies suggest that correcting LH deficiency may not be an efficient protocol based on the observation that there has been abundance of LH in cows after formation of cystic ovarian follicles. Cystic ovarian follicles that are heavily luteinized respond to prostaglandin F2? (PGF2?).
Review
Authors: Larson R. L. , Hardin D. K.
Published: March 2023

Neospora caninum is a protozoal parasite implicated as a leading cause of abortion in some dairy and beef herds. The bovine is an intermediate host for the parasite, and therefore N. caninum is not transmitted horizontally from infected individuals in the herd to non-infected individuals. Transmission can take place vertically from dam to fetus during pregnancy when tachyzoites from maternal tissues enter the bloodstream and cross the placenta to cause fetal infection. Once infected, an animal is considered to be infected for life and a female will pass the infection to a high percentage of her offspring. Although fetal infection in some herds is common, abortion following fetal infection is a fairly rare event, with risk of abortion being greatest in the first pregnancy following infection and decreasing thereafter. Vertical transmission of the parasite results in an endemic abortion pattern within family lines. N. caninum can also be passed from the definitive host, the canine, to cattle, presumably via contamination of feed or water with oocyst-infected faeces. Canines become infected by consuming N. caninum-infected tissue. Horizontal transmission of the parasite results in an epidemic abortion pattern which can cause a high percentage of susceptible females to abort. Laboratory tests are able to identify maternal, fetal, or calf infection with the parasite, but because of the low percentage of abortions in infected dams in endemically-infected herds, predictive value of N. caninum infection is low for abortion causation, and statistical tests to attribute risk are needed to infer abortion causation.
BVD Decision / Management Guidelines for Beef Veterinarians
Authors: Larson R. L. , Grotelueschen D. M. , Brooks K. V. , Dargatz D. A. , Ellis J. A. , Hunsaker B. D. , Lewis S. D. , MacGregor D. S. , Smith R. A. , Sprowls R. W. , Traffas V.
Published: March 2023

Characteristics of bovine viral diarrhoea virus (BVDV), such as genetic diversity and ability to induce a persistently infected (PI) carrier state, make its control a challenge. The Academy of Veterinary Consultants (AVC) drafted and approved a position statement in 2001 resolving to adopt measures to control and target eventual eradication of BVDV from North America. As part of this effort, the AVC formed an ad hoc committee to develop a document to provide guidelines for BVDV control based on the best current information. The final document was approved by the AVC in 2003, and provides management guidelines for control of BVD in beef cow-calf herds, stocker operations and feedlots.
Causes of bovine abortion in the North-Central United States
Authors: Yamini Behzad , Mullaney Thomas P. , Patterson Jon S. , Fitzgerald Scott D. , Steficek Barbara A. , Kennedy Frances
Published: March 2023

During 1983-2001, a total of 1618 aborted fetuses from farms with multiple abortions were examined to determine the cause. A specific cause was determined in 592 (36.59%) cases. Infectious agents associated with inflammatory reaction were detected in 435 (26.88%) cases. Bacterial abortions were identified as the most common infectious cause of abortion, 265 (16.38%) cases, with Arcanobacterium pyogenes being the most frequently isolated bacterium. Viral causes of abortion were diagnosed in 77 (4.76%) cases, protozoal in 55 (3.39%) cases, and 38 (2.34%) of the cases were diagnosed as mycotic abortion. There were also 65 (4.01%) cases of congenital myopathy and/or cardiomyopathy, 12 (0.74%) cases of congenital renal oxalosis and 38 (2.34%) cases of multiple congenital malformations. Lesions suggestive of infection were present in 157 (9.70%) fetuses or placentas in which no infectious organisms were identified. The cause of 873 (53.96%) abortions was not determined. Serological examination of 590 single or paired serum samples from aborting dams was of little diagnostic value for bovine viral diarrhoea (BVD), infectious bovine rhinotracheitis (IBR) and leptospiral abortions. Five serum samples from aborting dams (38 examined) had high Neospora caninum antibody titres (800-12?800). Aborted fetuses from these dams had encephalitis and myocarditis. Serological examination of thoracic fluid from 80 fetuses was of little diagnostic value for IBR, BVD, Neospora sp., Toxoplasma sp. and leptospiral abortions.
Case report
Authors: Hendrickson Eli H. S. , Riley Christopher B.
Published: March 2023

A 4.5-kg urachal abscess involving the umbilical arteries was diagnosed in a 12-week-old Holstein heifer. The urinary bladder wall was adhered to the mass, and there were multiple adhesions of the jejunum, which were associated with incomplete extra-mural obstruction. Adhesiolysis was completed. One section of partially obstructed jejunum was resected and a side-to-side anastomosis performed. Recovery from surgery was uneventful.
Important elements of the HACCP process to control Johne's disease, bovine viral diarrhoea virus (BVDV, and bovine leukaemia virus (BLV)
Authors: Pence Mel , Thomson John U. , Cole Dana
Published: March 2023

The hazard analysis critical control point (HACCP) programme was developed to address food safety issues and has been mandatory in all cattle harvest plants since January 2000. HACCP process control procedures provide a systematic approach to the identification and control of a variety of biological, physical and chemical hazards within a food production system. In addition, the seven steps of HACCP offer a proven systematic approach that addresses biological problems. This approach can be adapted to on-farm production problems of a non-food safety nature. The risk a disease poses to a production unit is assessed, critical control points (CCP) for a specific disease are identified, these risk factors are addressed and best management practices are applied to reduce or eliminate disease risk. Limits are established for each disease, monitoring procedures are applied to each CCP, and corrective action is applied when disease level surpasses the set limit. Thus, a record system is created that documents the plan, and verification procedures are established to ensure the plan is working. Together, practitioners and producers can use this method to systematically address specific production problems related to disease control. This paper describes how HACCP might be used to address bovine viral diarrhoea persistent infection (BVD PI), bovine leukosis [leukaemia] virus (BLV) and Mycobacterium avium subsp. paratuberculosis (Johne's disease) and to prevent introduction or systematically reduce or eliminate the impact of these diseases on the production unit.
Case report
Authors: Hutchinson L. J. , Weinstock D. , Byler L. I.
Published: March 2023

A total of 234 adult, mixed-breed dairy goats in the USA were screened for paratuberculosis antibodies using ELISA and agar gel immunodiffusion (AGID) methods licensed for bovine use in January 2000. All does which had one or more parturitions were included in the serological screening tests conducted at 6-month intervals over a 2-year period. Test-positive animals were removed from the herd and, at the owners' discretion, were either euthanized and examined by necropsy, histopathology and culture, or sold for meat purposes. Management practices for control of paratuberculosis transmission were also implemented. There was good agreement between ELISA and AGID test results (Kappa=0.625). Of 41 seropositive goats submitted for necropsy, 39 (95%) were paratuberculosis-positive. Over a 2-year period, herd seroprevalence declined from 9.83 to 3.59% among adult does. Testing for Mycobacterium avium subspecies paratuberculosis and adopting management practices recommended for control of paratuberculosis in cattle appeared to reduce the seroprevalence of paratuberculosis in this goat herd.
Case Study
Authors: Cleveland Susan M. , Cleveland Matthew A. , Salman Mo D. , Mortimer Robert G. , Van Campen Hana
Published: March 2023

This study was conducted to determine the effect of removing cattle persistently infected (PI) with bovine viral diarrhoea virus (BVDV) on seroprevalence and prevalence of PI calves in an endemically infected beef herd in Colorado, USA. The prevalence of PI animals and the serum neutralizing (SN) titres of heifers, bulls and calves were determined for three cow-calf herds in a beef cattle ranch over a period of 2 years [date not given]. In the first year, identified PI animals were removed from the herd within 3 weeks of identification. Five PI animals of 2921 (0.171%) cattle tested were identified in the first year. One PI animal was a yearling heifer and the remaining 4 were calves. Three of the 4 PI calves identified were removed prior to the breeding season, when the calves averaged 2 months of age. One PI animal was not identified until weaning at 6 months of age, and was present in the herd during the breeding season. The percentage of animals with high SN titres (?1:512) were 20.6% (367/1784) to type I BVDV and 44.8% (799/1784) to type II BVDV. In year 2, PI calves were not identified and the percentage of calves with high SN titres to BVDV type I and type II decreased to 5.91 (58/981) and 18.04% (177/981), respectively. Removal of PI animals in the first year reduced transmission of BVDV as evidenced by a significant decrease in the prevalence of high BVDV SN titres and the absence of PI animals the following year. These findings support the use of PI animal identification and removal as an effective BVDV control strategy in beef herds.
Efficacy of mid-summer doramectin pour-on application for parasite control in spring calving cow-calf herds in the Northern Great Plains
Authors: Lardy G. P. , Stoltenow C. S. , Baumann T. A. , Leupp J. L. , Seeger J. T. , Odde K. G.
Published: March 2023

One-hundred-twenty cow-calf pairs grazing native pasture in southcentral North Dakota were used in a prospective study to evaluate efficacy of mid-summer topical doramectin application for control of lice compared to non-treated controls. Pairs were allocated to one of two treatment groups and placed on eight separate pastures. On day -40, cows were weighed and body condition score (BCS) evaluated. On day 0 (day of treatment) pairs allotted to the treatment group were treated topically with 227 mcg/lb of doramectin in mid-July. Cows were examined for lice monthly from day 134 through day 238. Fecal samples collected from cows and calves were examined for parasite eggs, and horn fly counts were taken on selected cows in each replicate. Weights and BCS (cows only) were taken for cows and calves. Steer calves were committed to a finishing program to evaluate effect of doramectin on feedlot performance and carcass characteristics. Percentage of cows positive for lice in the doramectin-treated group was lower on days 161-162, 184-185, 210-211 and 238-239 than non-treated cows. Doramectin-treated cows and calves had lower fecal egg counts on days 21 and 42 than non-treated controls. Mid-summer application had no effect on cow BCS, cow body weight, calf average daily gain or steer carcass characteristics. Mid-summer application of doramectin was effective for control of lice through the winter. Internal parasite load in this study may not have been high enough to detect a difference in performance in spring calving cow-calf pairs.
Magnitude and patterns of ruminal hydrogen sulfide production, blood thiamine concentration, and mean pulmonary arterial pressure in feedlot steers consuming water of different sulfate concentrations
Authors: Loneragan G. , Gould D. , Wagner J. , Garry F. , Thoren M.
Published: March 2023

Twenty-seven single-source, yearling crossbred steers (713 lb; 324 kg) were used to evaluate the effect of water sulfate concentration on the patterns and magnitude of ruminal gas cap hydrogen sulfide, blood thiamine concentration and mean pulmonary arterial blood pressure (mPAP). Target water sulfate concentrations were 125, 500 and 2000 mg sulfate/L of drinking water, while the observed water sulfate concentrations were 136, 583 and 2,360 mg/L. Ruminal gas cap hydrogen sulfide concentrations were measured three times per week for 10 weeks, then once a week for seven additional weeks. On days 29 and 113, whole-blood samples were collected and analyzed for thiamine concentration. Pulmonary arterial blood pressures were measured on day 100. Ruminal gas cap hydrogen sulfide concentrations decreased to day 15, then increased and peaked by day 31, and finally decreased and remained relatively stable. The peak in hydrogen sulfide concentration was associated with an event of polioencephalomalacia in the treatment group consuming water with 2,360 mg/L sulfate, and the greatest frequency of polioencephalomalacia events in cattle in an adjacent commercial feedlot consuming water with a similar sulfate concentration. Ruminal hydrogen sulfide concentration increased with increasing water sulfate concentration (P<0.05). A treatment effect on blood thiamine concentration was not detected (P=0.29). Mean pulmonary arterial pressure increased linearly with increasing water sulfate concentration (P<0.05). Ruminal gas cap hydrogen sulfide concentrations greater than 1000 ppm provide evidence of excessive sulfur consumption. Pathological concentrations of ruminal sulfides appear central to the pathogenesis of sulfur-associated polioencephalomalacia.
Environmental mastitis pathogens isolated from bulk tank milk collected on California dairies
Authors: Kirk John H. , Glenn Kathy S. , Cullor James
Published: March 2023

The objective of this prospective study was to determine the prevalence of potential environmental bacterial mastitis pathogens in bulk tank milk, and to determine their antibiotic susceptibility patterns. Bulk tank milk samples from over 400 California dairies routinely submitting samples to the Milk Quality Laboratory were initially screened. Once potential environmental bacterial mastitis pathogens were found in bulk milk from a dairy, the dairy was repeatedly sampled on a monthly basis. Over a nine-month period, 93 dairies were identified with these bacteria, and 381 isolates were collected. Most common isolates were Streptococcus uberis (42.3%), Streptococcus dysgalactiae (16.3%) and Enterococcus faecium (10.5%). Bacterial isolates (335) from 73 dairies which had at least three isolates were subjected to Minimum Inhibitory Concentration (MIC) testing using 10 antibiotics. A wide range of susceptibility to antibiotics was found. Streptococcus dysgalactiae tended to have lower MIC values to the test antibiotics than the other isolates. The non-streptococcal bacteria tended to have the highest MIC values.
AABP Association and Conference News
Authors: American Association of Bovine Practitioners
Published: March 2023

Description of the Annual Conference of the American Association of Bovine Practitioners (38th : 2005), officers, district news, events, awards, and other news.
Congenital myopathy, cardiomyopathy and vitamin E and/or selenium levels in cattle
Authors: Yamini Behzad , Patterson Jon S. , Mullaney Thomas P. , Stowe Howard D.
Published: March 2023

Congenital myopathy involving the myocardium, skeletal muscle and tongue was diagnosed in 58 of 1208 aborted bovine fetuses submitted for necropsy between February 1983 and June 1994. Microscopic characteristics of muscle lesions were consistent with segmental nutritional myopathy. Liver vitamin E and selenium (Se) concentrations in 40 of the 58 fetuses with myopathies were assayed, and 38 (95%) had either a deficiency of vitamin E (n=27), Se (n=2) or both micronutrients (n=9). Over this time period, 570 bovine fetal livers, including those from the 40 of the 58 cases with congenital myopathy, were assayed for vitamin E and Se concentrations. Vitamin E values varied from non-detectable to 57 æg/g of dry weight (DW), and Se values from 0.05-10.96 æg/g (DW), indicating placental transfer of both elements and fetal ability to sequester both nutrients in the liver. For 190 cases, deficiencies of liver vitamin E (n=119), Se (n=29), or both (n=42) were the only abnormal findings.
Considerations for bovine viral diarrhea (BVD) testing
Authors: Larson R. L. , Brodersen B. W. , Grotelueschen D. M. , Hunsaker B. D. , Burdett W. , Brock K. V. , Fulton R. W. , Goehl D. R. , Sprowls R. W. , Kennedy J. A. , Loneragan G. H. , Dargatz D. A.
Published: March 2023

Available diagnostic tests for bovine viral diarrhea virus (BVDV) and the persistently infected (PI) BVDV carrier state are reviewed and presented in table format. The test of choice will depend on the age of animal being tested, whether the animal is alive or dead and whether the veterinarian is only interested in identifying PI animals or if transiently infected (TI) animals are also of interest. Economic considerations, including the likelihood of finding a PI animal in a given population (expected prevalence), cost of disease due to the presence of a PI animal and the economic risk of selling a PI animal to a customer, will impact the choice of BVD testing strategy. Potential advantages and disadvantages for the available laboratory tests and suggested tests for particular situations are presented in table format.
Case management of Ureaplasma diversum in a replacement dairy heifer operation and a commercial beef herd
Authors: Thomson Daniel U. , Ritter Paul , Stevens Elliot T. , White Brad J.
Published: March 2023

A herd of 18-month-old heifers from Kansas, USA with low pregnancy rates is reported. The heifers were exposed to Holstein bulls for 90 days and presented with clinical signs of abortion, failure to conceive, and had reddened vulvas with small blister-like lesions. Vaginal swabs of the lesions were positive for U. diversum using the polymerase chain reaction test. At the time of diagnosis, the Holstein bulls were housed with beef bulls used for the producer's commercial cow/calf operation. Preputial swabs confirmed that all dairy and beef bulls were positive for U. diversum. The dairy heifers and all bulls were sexually rested for 28 days and fed 350 mg chlortetracycline (CTC)/head/day. Eleven of the 12 bulls remained preputial swab-positive for U. diversum after 28 days of CTC treatment. Following the 28-day rest period, the Holstein bulls were returned to the dairy heifer pen. Out of the 250 dairy heifers, 238 were pregnant 90 days after the bulls were re-introduced. Additionally, the producer elected to use the Ureaplasma-positive beef bulls to breed his commercial beef cows and heifers. Upon rectal palpation, 282 of 285 beef cows and heifers were pregnant in the fall. These results indicate that feeding 350 mg CTC/head/day did not eliminate U. diversum from the prepuce of the bulls. Ureaplasma in this case was either non-pathogenic, or the beef cows and dairy heifers were immune due to prior exposure, which allowed Ureaplasma-positive bulls to breed both dairy and beef cattle and achieve high conception rates.
Effect of tilmicosin alone or in combination with Mannheimia haemolytica toxoid administered at initial feedlot processing on morbidity and mortality of high-risk calves.
Authors: Bryant T. C. , Nichols J. R. , Farmer T. D. , Miles D. G.
Published: March 2023

A total of 3,996 high-risk steer calves were used to compare effects of metaphylactic treatment with tilmicosin (TIL) alone or in combination with an adjuvanted Mannheimia haemolytica toxoid (MHT) at feedyard arrival on health parameters and economic return in a commercial feedlot setting. Steers receiving TIL-MHT at processing had 17% fewer first time treatments for BRD (P=0.0002) than calves in the TIL group, and a 19% lower relapse rate (P=0.003). TIL-MHT calves had 22% less mortality (P=0.03) than calves in the TIL group. Calves receiving TIL-MHT had $1.37 (P<0.0001) and $13.14/head (P=0.03) lower therapy and mortality costs, respectively, than calves in the TIL group. In total, combined processing, therapy, railer (culls) and mortality costs for TIL-MHT calves were $14.77 lower (P=0.01) than TIL group calves.
AABP Conference (2007): Awards
Authors: Bovine Practitioners American Association of
Published: March 2023

Description of the 2007 American Association of Bovine Practitioners Conference.
AABP Conference (2007): Receptions
Authors: Bovine Practitioners American Association of
Published: March 2023

Description of the 2007 American Association of Bovine Practitioners Conference.
Effect of Vaccination and Weaning Timing on Backgrounding Morbidity in Preconditioned Beef Feeder Calves
Authors: White B. J. , McReynolds S. , Goehl D. , Renter D. G.
Published: March 2023

Bovine respiratory disease is the most common illness in post-weaned beef calves, and numerous pre-conditioning programs have been designed to mitigate the impact of this disease syndrome. Preconditioning programs rely on proper implementation of tools, including vaccination and weaning, to prepare the calf to successfully overcome disease challenges. Our objective was to determine whether backgrounding morbidity was associated with the timing of previous vaccinations and the number of days weaned prior to commingling of beef feeder calves. Data were procured over a six-year period from 85 producers that preconditioned calves and placed them in a commingled backgrounding lot for approximately three months. Generalized linear mixed models were utilized to assess the impact of the number of days between first and second viral vaccinations, number of days between the final viral vaccination and commingling and the number of days weaned prior to commingling. Hypothesis testing was performed using P <0.10 due to the relatively small sample size when year and origin farm were considered. Morbidity during the backgrounding phase was significantly higher ( P <0.10) when the time between initial and booster vaccination was less than 14 days. No morbidity differences were found based on weaning time or the proximity of the final vaccination to commingling. Our results illustrate that the timing of vaccinations influences health outcomes of preconditioning programs, and that further research is necessary to provide definitive recommendations regarding timing of vaccination and weaning.
Drug Residue Avoidance and Beef Quality Assurance Practices in Dairy Cattle
Authors: Knust B. , Nelson L. , Shott L. , Pederson L. , Fajt V.
Published: March 2023

As part of an overall educational program, bovine veterinarians' knowledge of dairy beef quality assurance was assessed, with particular emphasis on residue avoidance practices. A survey instrument was developed and sent to all members of the American Association of Bovine Practitioners (AABP) in the member newsletter. Topics included respondent demographics, drug administration practices, record-keeping practices, impression of clients' attitudes and behaviors regarding drug residues, drug information sources, understanding of cull cattle marketing and processing, and interest in Dairy Beef Quality Assurance. Survey respondent demographics were similar to the general AABP membership. Survey results highlighted a need for continued educational efforts for and by veterinarians regarding extra-label drug use, residue avoidance and general knowledge about market dairy beef processing.
Serum Protein Levels in Holstein Calves Fed Pasteurized-Frozen-Thawed or Unpasteurized First-milk Colostrum
Authors: Medina-Cruz Mario , Cruz C. , Montaldo H. H.
Published: March 2023

This study compared serum protein (SP) concentrations in male and female Holstein calves fed pasteurized-frozen-thawed colostrum (PFTC) or unpasteurized colostrum (UPC) in a Mexican commercial dairy herd. To prepare PFTC, first-milk colostrum was collected and mixed to form 12 batches. All batches were pasteurized at 145°F (63°C) for 30 minutes and poured into 2.11 quarts (2 L) plastic bags for freezing for a minimum of 24 hours before use. Prior to feeding, frozen bags of colostrum were thawed in water at 122 to 131°F (50 to 55°C) for 15 minutes, and fed three times to each calf during the first 22.1 hours of life. Calves receiving UPC were hand-fed 1.74 quarts (1.65 L) of colostrum per feeding for three consecutive feedings with a suckling bottle in the first 22.9 hours of life. Blood from each calf was collected between 24 and 96 hours after birth. The SP level was 5.92±0.15 g/100 mL for calves receiving PFTC and 6.53±0.14 g/100 mL for those receiving UPC ( P =0.0048). The percentage of calves with failure of passive transfer (FPT) of immunoglobulins with SP levels less than 5.2 g/100 mL was 24% for calves fed PFTC and 3.8% for calves fed UPC ( P =0.06).
Effects of concurrent metaphylaxis with chlortetracycline and tulathromycin on the health and performance of high-risk beef calves
Authors: Wallace Justin O. , Reinhardt Chris D. , Thomson Daniel U.
Published: March 2023

A total of 463 steers and bull calves (average body weight 447 lb or 203 kg) were used to determine the effect of feeding chlortetracycline (CTC) to calves metaphylactically treated with tulathromycin at arrival processing in a research feedlot. Experimental treatments consisted of three growing diets top-dressed with either no pellets (CON) or pellets containing CTC (4 g/lb or 8.89 g/kg) administered at a rate of 10 mg/lb (22 mg/kg) body weight (BW) for two five-day intervals with a one-day break in between (CTC) or pellets containing no CTC fed in the same amount per unit of BW (1.12 lb or 2.46 kg/hd) and for the same time period as the CTC treatment (PP). Calves were enrolled in the study for 41 days. No difference in performance, morbidity or mortality was found among the three treatments.
Myositis due to Mannheimia haemolytica infection in a beef heifer
Authors: Lamm Catherine G. , Step D. L. , Krehbiel Cling R. , Love Brenda C.
Published: March 2023

In this study, a 10-month-old, 447 lb (203 kg), mixed-breed beef heifer with elevated rectal temperature, weight loss and clinical signs suggestive of respiratory disease was presented. This heifer was from a group of 360 mixed-breed, high-risk heifers purchased and transported to the research feedlot at the Oklahoma State University Willard Sparks Beef Research Center, USA. Despite extensive consecutive treatment with antimicrobials, the heifer continued to have elevated rectal temperature and weight loss. The heifer died 22 days after arrival at the feedlot. Necropsy examination revealed an unusual localized necrotizing myositis that concentrated along the musculature of the ventral cervical area and into the adjacent right axilla. Severe bronchopneumonia, confirmed grossly and histologically, was the presumed the cause of death. A pure culture of Mannheimia haemolytica was cultured from the skeletal muscle and the lung. The strain of M. haemolytica isolated from the lung and muscle was resistant to oxytetracycline and tilmicosin, and susceptible to ceftiofur and enrofloxacin by antimicrobial sensitivity testing. This infection was likely due to septicemia following severe fibrinous bronchopneumonia and pleuritis caused by M. haemolytica.
Efficacy of a modified-live virus vaccine administered to calves with maternal antibodies and challenged seven months later with a virulent bovine viral diarrhea type 2 virus
Authors: Zimmerman Alicia D. , Buterbaugh Robin E. , Schnackel John A. , Chase Christopher C. L.
Published: March 2023

A total of 22 commercial dairy calves were used to determine if vaccination of a modified-live bovine viral diarrhoea virus (BVDV) vaccine with adjuvants in the face of maternal antibody will protect calves from a virulent type 2 BVDV challenge within seven months post-vaccination, following the loss of maternal antibody. Neonatal calves were obtained prior to consuming colostrum and were randomly divided into three groups. Group 1 calves were fed an antibody-free colostrum supplement within six hours of birth. Calves in Group 2 and Group 3 were fed pooled colostrum obtained from cows vaccinated eight weeks prior to calving with a commercial inactivated combination vaccine containing BVDV1 and BVDV2. Group 2 calves were vaccinated at approximately 4.5 weeks of age with a commercial modified-live virus combination vaccine containing BVDV1 and BVDV2. Calves in Groups 1 and 3 were sham vaccinated. Seven months after vaccination, when calves in Group 3 became seronegative to BVDV2, calves in all three groups were challenged intranasally with virulent BVDV2, strain 1373. Calves that received colostrum and were vaccinated had only mild or no clinical diseases. Calves that did or did not receive colostrum and were sham vaccinated, developed severe diseases, with a 33-50% mortality rate. In this study, young calves vaccinated with a modified-live virus vaccine with adjuvants in the face of maternal antibody were protected against a virulent strain of BVDV.
Role of individual animal diagnosis and treatment in the training of food supply veterinarians
Authors: Tyler Jeff W. , Schultz Loren G.
Published: March 2023

Instruction of individual animal skills remains a core component of food supply medicine education. Recent surveys clearly demonstrate that food animal practitioners consider individual animal medicine skills to be central to the practice of veterinary medicine. Instruction of individual animal medicine skills can occur in a variety of venues, including in-house medicine and surgery, traditional ambulatory practice, specialized instruction in production medicine, and private practiced-based instructional experiences. The traditional in-house clinical rotation has both advantages and disadvantages in the instruction of veterinary students. Optimal instructional experiences should attempt to match both the content and context of instructional experiences with students' future professional employment.
AABP Association and Conference News
Authors: American Association of Bovine Practitioners
Published: March 2023

Description and highlights of the 41st Annual Convention American Association of Bovine Practitioners (2008) and information about officers, district news, events, awards, and other news.
Integrated BVD control plans for beef operations
Authors: Grooms Daniel L. , Givens M. Daniel , Sanderson Michael W. , White Bradley J. , Grotelueschen Dale M. , Smith David R.
Published: March 2023

Infection of cattle with bovine viral diarrhea virus (BVDV) can result in a wide assortment of disease manifestations. Diseases related to BVDV cause economic losses to cattle producers throughout the world due to decreased performance, loss of milk production, reproductive wastage, and increased risk of morbidity and mortality. There are three broad types of BVDV infection: acute, fetal, and persistent. It is persistent infection that is predominantly responsible for perpetuating the virus in cattle populations, and animals persistently infected with BVDV are an important target for control of transmission. The approach to BVDV control must be multidimensional, with consideration for all tools at our disposal including strategic management of the production system, diagnostic investigation, and vaccination. Decisions regarding BVDV control should factor into consideration the strategy's potential to decrease risk for transmission and its cost. Producers must first know with reasonable certainty if the virus is circulating in the herd. If the virus is found in the herd, then the appropriate actions are those that minimize the harmful effects of infection or work to eliminate the virus. If the virus is not present in the herd, then the appropriate actions are those that keep the herd free of BVDV and minimize losses should the virus be introduced. Recently, a new website was created to consolidate BVDV information in a single location on the internet: www.bvdinfo.org.
Comparison of two multivalent viral vaccine programs in feedlot calves at high risk of developing undifferentiated fever/bovine respiratory disease
Authors: Wildman Brian K. , Jim G. Kee , Perrett Tye , Schunicht Oliver C. , Hannon Sherry J. , Fenton R. Kent , Abutarbush Sameeh M. , Booker Calvin W.
Published: March 2023

A field study was conducted to compare the relative effects of two multivalent viral vaccine programs on animal health, feedlot performance, and carcass characteristics of feedlot calves at high risk of developing undifferentiated fever/bovine respiratory disease (UF/BRD). Upon arrival at the feedlot, 3,264 animals were randomly allocated to one of two experimental groups: PYR5 (Pyramid® 5, Fort Dodge Animal Health, Division of Wyeth, Overland Park, Kansas) or EXP5 (Express® 5, Boehringer Ingelheim Vetmedica, Inc., St. Joseph, Missouri). All animals were re-vaccinated with their respective vaccines at 139 days-on-feed. The initial undifferentiated fever (UF) treatment rate was significantly (P<0.05) lower in the PYR5 group than in the EXP5 group (RR=0.70, 95% CI=0.53-0.93). On a live-weight basis, the dry matter-to-gain ratio (DM:G) was significantly (P<0.05) improved in the PYR5 group compared to the EXP5 group. Yield grades were improved in the PYR5 group, with a significantly (P<0.05) lower proportion of YG USDA 3 carcasses in the PYR5 group compared to the EXP5 group. No significant differences were detected in any other animal health, feedlot performance, or carcass characteristic variables between the experimental groups at the P<0.05 level. The economic analysis showed an advantage of $1.36 US per animal in the PYR5 group due to the lower initial UF treatment rate and proportion of YG USDA 3 carcasses.
Effects and economic implications of metaphylactic treatment of feeder cattle with two different dosages of tilmicosin on the incidence of bovine respiratory disease (BRD)
Authors: Corbin Marilyn J. , Gould Jared A. , Carter Brandon L. , McClary David G. , Portillo Tom A.
Published: March 2023

Two studies were conducted to evaluate the efficacy of tilmicosin for metaphylactic treatment of bovine respiratory disease (BRD), and subsequent effects on calf performance, in newly received, high-risk feedlot cattle. Calves in each study were randomly assigned to one of three treatment groups: negative control; 4.55 mg/lb body weight (BW) (10 mg/kg BW) tilmicosin (TIL10); or 9.1 mg/lb BW (20 mg/kg BW) tilmicosin (TIL20). In Study I, calves receiving tilmicosin had lower BRD morbidity (P<0.01) and mortality rates (P=0.02) compared to controls. Furthermore, BRD morbidity was lower (P≤0.05) in the TIL20 (16.8%) compared to the TIL10 (24.3%) group. Average daily gain was improved (P<0.01) in both tilmicosin metaphylaxis treatment groups compared to controls when deads and removals were not included in the final calculations (2.9 lb and 3.0 lb vs 2.8 lb or 1.32 kg and 1.36 kg vs 1.27 kg), as well as when deads and removals were included in the evaluation (2.7 lb and 2.8 lb vs 2.4 lb or 1.23 kg and 1.27 kg vs 1.09 kg, respectively). Calves treated metaphylactically with tilmicosin had greater economic return per pen (P<0.01) than did controls. In Study II, calves in both TIL10 and TIL20 treatment groups had lower (P≤0.05) morbidity compared to controls (68.5, 49.9, and 44.0% for control, TIL10, and TIL20, respectively). No significant differences in performance were observed between treatment groups.
Blackleg (Clostridium chauvoei infection) in beef calves
Authors: Daly Russell F. , Miskimins Dale W. , Good Roland G. , Stenberg Thomas
Published: March 2023

Blackleg (Clostridium chauvoei infection) has long been recognized as a cause of death in calves grazing summer pastures. Clinical signs are not often observed in affected calves due to the peracute nature of the disease, but may include fever, lameness, and swelling and crepitation over large muscle groups, followed by collapse and death. Typical gross and histopathologic lesions in these muscle groups are well-described and include gelatinous, gassy subcutaneous changes, along with well-defined muscle necrosis. Areas of necrosis can also be present in myocardium, diaphragm, and tongue, among other sites. Primary gross lesions consisted of pleuritis and pericarditis in animals examined in this report. More typical blackleg lesions were found in some but not all calves, including necrosis in thigh and abdominal muscles, dark discoloration of diaphragm muscle, and histologic evidence of necrotic myocarditis. Practitioners finding these lesions in animals found dead on pasture should consider C. chauvoei infection as the diagnosis regardless of whether muscle necrosis lesions are present.
Clinical and Economic Effects of an Internal Teat Sealant at Dry-off on the Incidence of Clinical Mastitis in Early Lactation
Authors: Baillargeon Paul , LeBlanc Stephen J.
Published: March 2023

Twelve commercial dairies in Quebec, Canada, evaluated the clinical and economic effects of using an internal teat sealant (ITS; Orbeseal®) combined with standard intramammary antibiotic dry-cow treatment on the incidence of clinical mastitis in early lactation. A total of 1,334 Holstein cows were randomly assigned to treatment of all four quarters with an antibiotic dry cow treatment (ADCT) alone or with antibiotic treatment and an internal teat sealant (ADCT+ITS) at dry-off. The incidence rate of clinical mastitis per 100 cow-days at risk during the first 105 days-in-milk was 22% lower (relative risk= 0. 78; 95% confidence interval 0.61 to 1.01) for theADCT+ITS group than for theADCT group. The daily probability of experiencing clinical mastitis, starting at calving, was reduced by 24% for the ADCT+ITS group. The net benefit, based on lost milk production associated with clinical mastitis, was approximately $20 Canadian (CDN) per cow for theADCT+ITS group due to the lower incidence of clinical mastitis, particularly soon after calving.
Reproductive Endocrinology and Hormonal Control of the Estrous Cycle
Authors: Lamb G. C. , Smith M. F. , Perry G. A. , Atkins J. A. , Risley M. E. , Busch D. C. , Patterson D. J.
Published: March 2023

Maximizing reproductive efficiency depends upon whether a heifer attains puberty before the start of the breeding season, conceives early in the breeding season, calves unassisted, raises the calf to the time it is marketed, and the heifer/cow must conceive to calve early during the subsequent calving seasons. Failure to do so constitutes reproductive loss, which is estimated to cost the US beef industry around $500 million annually. Estrous synchronization and artificial insemination are among the most powerful and applicable technologies for genetic improvement of beef herds. Development of new and improved methods of synchronizing estrus and ovulation depends on an understanding of the physiological and hormonal mechanisms controlling the estrous cycle and the initiation of estrous cyclicity in noncycling heifers and postpartum cows. It is imperative for veterinarians and producers to familiarize themselves with commercially available estrous synchronization products and the physiologic mechanisms by which these products synchronize estrus and (or) ovulation in cattle.
Veterinary Related Issues Associated with Feeding Free Fatty Acids to Dairy Cows Pre- and Postpartum
Authors: Thornsberry R. M. , Kertz A. F.
Published: March 2023

In confined dairy production units, reproductive efficiency is a major concern for the attending veterinarian. Many parameters influence reproductive performance of lactating dairy cows. While attending veterinarians do not necessarily formulate dry cow, transition, and lactating cow diets, they could influence how these diets are formulated and fed. With increasing costs of commodity grains and traditional starch sources, producers are seeking economical means to supply dairy production animals with dietary energy. Indirect fat supplementation, in the form of grain and oil seeds, and some forages such as corn silage, are usual sources of dietary fat. In addition to these common feed sources of lipid-based energy, the dairy practitioner has alternatives to provide free fatty acids to a dairy production animal diet. Dairy veterinarians must understand how provision of free fatty acids can influence reproductive performance and health.
Effect of Watering Trough Chlorination on Persistence of Mycobacterium avium subsp paratuberculosis
Authors: Cook Kimberly L. , Bolster Carl H. , Britt Jenks S. , Rothrock Michael
Published: March 2023

Continued increases in Johne's disease around the world suggest more information is needed to understand the mechanisms by which the causative agent, Mycobacterium avium subsp paratuberculosis (MAP), is spread among livestock on the farm site. Livestock watering troughs are frequented by all animals on a farm; they provide a moist, nutrient-rich environment for bacterial survival, and the trough basin provides a surface for bacterial adhesion (i.e., biofilm formation). The goal of this study was to determine whether addition of chlorine to trough water could prevent or reduce biofilms containing MAP on trough materials. MAP was inoculated into trough water containing normal trough water microbial flora. The concentration of MAP in biofilms on suspended 1.5 in x 0.6 in (3.8 cm x 1.5 cm) concrete, plastic, galvanized or stainless steel trough materials was evaluated. Chlorine (2 ppm) was added to the trough water on day 7, and then weekly for 70 days. The concentration of MAP in biofilms on the trough materials was measured using quantitative, real-time PCR to target the MAP-specific 1S900 sequence in DNA extracts. Chlorination was most effective against MAP on galvanized steel and stainless steel trough materials (99% reduction (t99) in biofilmassociated MAP in 15 and 16 days, respectively). This value was two to four times higher for MAP in biofilms on plastic and concrete materials (t99 of 33 and 66 days, respectively). Differences in effectiveness of disinfection may result from higher pH (pH 8.23) in troughs with concrete materials and lower chlorine availability in troughs with plastic materials. These results suggest that the effectiveness of chlorine disinfection depends on trough material construction, pH, and chlorine availability. Optimization of disinfection protocols and elimination of biofilms on trough surfaces should reduce persistence of MAP in trough waters.
Costs of Living for US Veterinarians in Food Animal Practice Compared to other Practice Categories and the Effect on Adjusted Income
Authors: Tyler Jeff W. , Aura Saku , Schultz Loren G.
Published: March 2023

The purpose of this study was to determine whether the cost of living (COL) experienced by veterinarians in the United States varied with their species emphasis. A total of 1191 entries were drawn from the American Veterinary Medical Association directory. A data set consisting of species emphasis category and addresses was systematically collected from the directory, and then cost of living indices (COLI) based on geographic locale were determined for each veterinarian using an internet-based tool. A Kruskal-Wallis analysis of variance on ranks was used to determine whether COL varied among species emphasis categories for veterinarians. Species category was significantly associated with cost of living (P < 0.001): companion animal-exclusive veterinarians had significantly higher median cost of living (99) than food animal predominant (84), food animal-exclusive (89), and mixed animal veterinarians (86). Equine-exclusive veterinarians had significantly higher COLI (94) than food animal predominant and mixed animal veterinarians. The COLI for companion animal-predominant veterinarians were significantly higher (89) than food animal-predominant veterinarians (84). No other pair-wise comparisons of species category COLI differed significantly. When income was adjusted for COL ($152,398), food animal-exclusive veterinarians had greater income than all other species defined categories, and exceeded that of companion animal-exclusive veterinarians by $48,577 per year. When adjusted for COL, companion animal-exclusive incomes were lower than all other species-defined categories.