bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of seroconversion with isolation of agents in transtracheal wash fluids collected from pneumonic calves less than three months of age
Authors: Virtala A.-M.K. , Grohn Y. T. , Mechor G. D. , Erb H. N. , Dubovi E. J.
Published: March 2023

The potential association between seroconversion to respiratory disease agents and isolation from transtracheal wash fluids (TTW) was investigated in pneumonic dairy calves <3 months of age. Naturally infected calves from 18 commercial dairy farms were used. At least one respiratory pathogen was cultured from the TTW of each calf. Blood samples were collected at the time of diagnosis and 3 weeks later. Most calves had evidence of maternal antibodies at 2 days of age to the same pathogens isolated from the TTW at the time of respiratory disease diagnosis. Evidence of an active immune response (seroconversion) to the organism in the TTW was a specified rise in titre between paired serum samples. False-negative results, i.e. failure to seroconvert to the organism isolated in the TTW, were seen in 8 of 9 (89%) calves with bovine diarrhoea virus in their TTW, 43 of 75 (57%) calves with Mycoplasma spp. in their TTW, 20 of 53 (38%) calves with Pasteurella multocida, 4 of 16 (25%) calves with Pasteurella haemolytica, and 5 of 13 (38%) calves with Haemophilus somnus isolates in their TTW. Reliance on paired-serological testing to identify the respiratory pathogens present in the respiratory tract of clinically pneumonic dairy calves <3 months of age is not recommended.
Preliminary evaluation of the effect of vaccination with modified live bovine viral diarrhea virus (BVDV) on detection of BVDV antigen in skin biopsies using immunohistochemical methods
Authors: DuBois William R. , Cooper V. L. , Duffy Jeanenne C. , Dean Darrin D. , Ball Roy L. , Starr Billie D.
Published: March 2023

Immunohistochemical (IHC) testing of skin biopsies (ear notch samples) is a method to identify cattle persistently infected (PI) with bovine diarrhoea virus (BDV). Skin biopsies were taken from 90 calves upon arrival (day 0) at a feedlot, and on days 14, 28 and 42 following arrival. Calves were vaccinated with modified live virus (MLV) BDV vaccine on days 1 and 14 following arrival. Additional samples were obtained from 50 of the calves between days 1 and 10 when they were treated for bovine respiratory disease. Immunohistochemical testing for BDV antigen was performed on all samples. One calf was positive for BDV antigen by IHC techniques on 5 skin biopsies. This calf was also positive by virus isolation (VI) on the buffy coat of a blood sample obtained on day 42 following arrival. All samples from the remaining calves were negative when tested with the IHC method. Other tests, VI and polymerase chain reaction, used to identify PI cattle may give positive results in cattle recently vaccinated with MLV BDV vaccine. This study suggests that IHC testing of skin biopsies may be advantageous over other tests to identify PI cattle recently vaccinated with MLV BVDV.
Effect of Pasture Trace Mineral Supplementation on Liver Mineral Levels and Feedlot Morbidity and Mortality
Authors: Grotelueschen D. M. , Wohlers A. , Dewey C. , Rush I. G. , Braselton W. E. , Hamar D. , Johnson A. B. , Pollreisz J. H.
Published: March 2023

Thirty-one Debouillet ewe lambs were exposed to elevated dietary copper (Cu) after being fed pelleted alfalfa from two separate feed mills which contained 33 and 45 ppm Cu. After consuming about 5.5 lb/day of this diet for approximately 50 days, signs of Cu poisoning became apparent (hemoglobinemia, hemoglobinuria). Cu toxicity was confirmed by a liver Cu concentration of 439 ± 36 (mean± SE) ppm in five dead animals. During the course of Cu exposure, eight of 31 ewe lambs died. Serum was collected from 10 ewe lambs showing extreme signs of Cu poisoning. Total, direct, and indirect bilirubin, and creatine kinase ( CK) were elevated in ewes consuming Cu. Ten extremely affected ewe lambs that had stopped consuming any feed received gelatin capsules (gavage) containing about 2 oz of a livestock salt/gypsum (76% calcium sulfate) mixture (2:1, weight basis) daily for 10 days. After 10 days of calcium sulfate treatment, serum bilirubin and CK were at or near normal concentrations and neither hemoglobinemia nor hemglobinuria were observed. Calcium sulfate administered in gelatin capsules appears to aid in the treatment of acute Cu toxicosis in sheep.
Case Report
Authors: Barringer Sam , Doster W. Robert
Published: March 2023

An 8000-unit dairy replacement calf ranch experienced high morbidity and mortality related to exposure of calves to aflatoxin M1 isolated in the milk replacer [place and date not given]. During the six-week exposure period, pre-weaning calf morbidity was 100%, and approximately 3000 calves died. Aflatoxin M1 is an intermediate metabolite of aflatoxin B1, and is found in milk of dairy cows consuming a contaminated ration. Histopathology demonstrated changes in the centrilobular hepatocytes as well as the biliary tree. Serum chemistry values indicated an ongoing liver disorder. Toxicologic evaluation of the milk replacer revealed the presence of aflatoxin M1. Within three days of removal of the affected milk replacer, morbidity and mortality levels returned to baseline levels for this ranch.
Effect of chemically altered and modified-live infectious bovine rhinotracheitis vaccines on fetal retention in beef replacement heifers during the first four months of gestation
Authors: Sprott L. R. , Forrest D. W.
Published: March 2023

The objective of this study was to determine whether vaccination of pregnant heifers with either chemically altered or modified live infectious bovine rhinotracheitis (IBR) vaccine would cause abortion when previously vaccinated with a chemically altered IBR vaccine. During pre-weaning processing and at weaning, 202 crossbred Brangus heifers were administered chemically altered infectious bovine rhinotracheitis virus (IBR) vaccines. At 60 to 120 days of gestation after first fall breeding, heifers were administered either a modified live virus (MLV) or a chemically altered IBR vaccine. Heifers at 60 to 90 days gestation, and those greater than 90 and up to 120 days gestation, were assigned by gestation category to one of three treatments: (1) a single IM injection of chemically altered IBR vaccine; (2) a single IM injection of modified live IBR vaccine; or (3) controls - no injections. Heifers were palpated 56 days after treatment to determine potential fetal loss. Subsequent calving information was used to confirm post-treatment palpation data. One heifer in each group aborted after treatment; these numbers did not differ among treatments (p=1.0) nor between gestation categories (p=1.0). Calving numbers verified that no fetuses were lost after post-treatment palpation. We concluded that a single dose of these vaccines in pregnant replacement heifers did not cause increased abortion rates compared to unvaccinated control heifers.
Comparison of serum steroidal hormone concentrations in buller steers, riders, and uninterested penmates Investigation of sickness, body weight, feed bunk status, and implant condition during buller occurrence
Authors: Meyer Brent D. , Apley Michael D. , Imerman Paula M.
Published: March 2023

Liveweight; rectal temperature (on days one and 3); implant condition; feed bunk condition; and serum hormone concentrations of trenbolone, trenbolone acetate, testosterone, progesterone, and estradiol 17? (on days one and 3) were measured in rider steers (n=17), buller steers (n=6) and control steers (n=18) at the time of bulling activity. Day one was considered the day of initial bulling activity. Liveweight at the time of bulling did not differ between groups (p=0.99), nor did rectal temperature at the time of bulling or the rectal temperature on day 3 post-bulling (p=0.93, p=0.80). There was a significant relationship between liveweight at the time of bulling activity and day one rectal temperature (p=0.002); however, the relationship between liveweight at the time of bulling and day 3 rectal temperature was not significant (p=0.31). The condition of growth hormone implants at the time of bulling did not differ between groups (p=0.27). Day one serum estradiol 17? concentration was significantly different between groups (p=0.05). The four steers that had detected (and quantified) levels of estradiol 17? on day one were riders; on the other hand, one buller and one control steer had detected (not quantified) levels of estradiol 17? on day one. The available data suggest that rider steers may have elevated levels of estradiol 17? as compared to bullers and non-involved penmates at the time of bulling activity. Furthermore, the results of this study suggest that the rider steer should be scrutinized as closely as the buller steer in future studies.
Association between forage particle size at initial feeding and the weigh-back and chewing activity in dairy cattle
Authors: Melendez Pedro , Rodriguez Oswaldo , Madrid Sergio , Donovan Art
Published: March 2023

A field trial was conducted at the University of Florida Dairy Research Unit (USA) to determine the relationship between initial coarse portion (ICP) particle size of a total mixed ration (TMR) and orts (weigh-back coarse portion, WBCP) of the same TMR. Additionally, the relationship between the ICP of a TMR and the proportion of cows chewing their cud 2.0 hours after feeding was determined. A random representative sample of TMR was taken from the feed bunk at initial feeding and 8 h later (weigh-back) every day from the same barn for 75 days. Samples were analysed for particle size content using a particle size evaluator. Proportion of the largest particles of the TMR was recorded. Additionally, the proportion of cows ruminating 2.0 hours after the morning feeding was recorded each day. Correlation and regression models between ICP and WBCP, and between ICP and the proportion of ruminating cows were calculated. The mean and standard deviation for ICP, WBCP and proportion of cows cud chewing were 14.2ñ6.6, 29.9ñ13.2 and 18.4ñ5.0%, respectively. The Pearson correlation coefficient between ICP and WBCP was 0.53, and the correlation coefficient between the proportion of cows chewing their cud and ICP in the TMR was 0.19. Initial coarse proportion was a predictor for WBCP (p<0.01), but was not a predictor of the proportion of cows ruminating 2 h after the morning feeding (p>0.05). These findings are suggestive of sorting of the TMR by the cows. Sorting was significantly higher (p<0.01) as the coarse proportion at the initial feeding increased, but this difference was likely of little biological significance.
Gastrointestinal nematodes in Quebec dairy cattle
Authors: Caldwell Vincent , DesCoteaux Luc , Bouchard Emile , DuTremblay Denis , Dohoo Ian R. , Markham Fred
Published: March 2023

A cross-sectional observational study was undertaken in Qubec dairy herds to evaluate regional and provincial prevalences of herds with gastrointestinal nematode (GIN) infections in lactating cows, and to determine risk factors associated with level of herd infection. The 5 most recently calved first-lactation cows from each of 208 randomly selected farms in 7 pre-defined regions of Qubec were sampled for faeces collection in July to August 1995. On the same occasion, a bulk tank milk sample was collected. A questionnaire on replacement and grazing practices was filled out for each farm. Faecal samples were examined and faecal egg counts were determined for trichostrongylids, Capillaria, Nematodirus, Trichuris, Strongyloides, and total GIN eggs. Weighted provincial estimates for prevalence of herds with positive coprologies to these parasites ranged from 4 to 93%. Median faecal egg count per herd was low (17 eggs per 5 g of faeces). Milk samples were submitted for an indirect ELISA test to detect antibodies against Ostertagia and Cooperia. Level of herd infection, as estimated by Ostertagia and Cooperia bulk tank milk ELISA titres (BTTs), varied (P<0.05) among regions. Questionnaire-derived risk factors most significantly associated with an increased bulk tank Ostertagia titre were exposure of lactating cows to pasture, intensive grazing of heifers on farm, contamination history of heifers' pasture, and incomplete pasture rotation for heifers. Very high stocking rates for cows and heifers and mechanical mowing during the grazing season of heifer pastures were associated with decreased ELISA titres. The results of this study indicate that the prevalence of nematode infections in first-lactation cows is very high in Qubec herds, with trichostrongylid infections being the most frequently observed. The association between bulk tank milk ELISA titres for Ostertagia and herd-level management practices capable of having an impact on exposure of cows to parasites suggest that BTTs could be a valuable indicator of herd infection level. Proper knowledge of regional prevalences, differences among mean regional titres, and the association between titres and of herd-level risk factors can help veterinarians with their decisions regarding parasite prevention and treatment.
Seroprevalence and productivity effects of infection with bovine leukemia virus, Mycobacterium avium subspecies paratuberculosis, and Neospora caninum in Maritime Canadian dairy cattle
Authors: Van Leeuwen J.A. , Keefe G. P. , Tiwari A.
Published: March 2023

To determine the effect of subclinical infection with bovine leukaemia virus (BLV), Mycobacterium avium subspecies paratuberculosis (MAP) and Neospora caninum (NC) on milk production in dairy cattle in 3 Maritime Canadian provinces, 90 dairy herds (all on monthly milk recording) were randomly recruited. Within each herd, a serum sample was obtained from approximately 30 randomly selected lactating animals. Samples were tested for antibodies against the agents using commercially available enzyme linked immunosorbent assays (ELISA). Associations were tested between 305-day milk production and test results for each pathogen using linear regression and controlling for sampling weights, within-herd clustering, provincial stratification, lactation number, and linear score somatic cell count. Overall, 20.8, 2.6, and 20.3% of cattle were test-positive for exposure to BLV, MAP, and NC, respectively. MAP test positive cows had significantly lower 305-day milk production than MAP test negative cows, when data were pooled for all lactations, and specifically for lactations one (1260 lb; 573 kg) and five (3020 lb; 1373 kg). There was a negative trend toward lower 305-day milk production for MAP test positive cows in lactation 2 and 4 compared with MAP test negative cows. In lactation 3, MAP test positive cows had significantly higher 305-day milk production (3248 lb; 1476 kg) than MAP test negative cows. No significant differences in production were observed for NC or BLV positive animals. Being test positive for one pathogen was not associated with being test positive for the other pathogens, and no interactive effects on 305-day milk production among pathogen test results were observed.
Association Between Serum Mineral and Vitamin A and E Concentration and Respiratory Disease in Beef Calves Entering Backgrounding Lots
Authors: Bagley Clell V. , Bingham Howard R. , Hall Jeffery O.
Published: March 2023

The objectives of this study were 1) to measure morbidity and mortality rates attributable to respiratory disease in beef calves originating from southwestern Utah, 2) to evaluate herd of origin vitamin/mineral serum concentration at backgrounding lot entry, and 3) to evaluate a potential association between serum concentrations of 29 minerals and vitamins A and E at backgrounding lot entry with respiratory disease in recently weaned beef calves. This was a prospective longitudinal study with matched case-control and cross-sectional studies nested within the main study design. Pen-specific morbidity rates attributable to respiratory disease ranged from 1.2% to 81.8%. Serum concentrations of vitamins A and E in calves sampled (n=224) from eight southern Utah ranches were commonly less than published low-normal values. In these data, there was no detectable association between serum vitamin A and E or mineral imbalances and respiratory disease. Herds that experience a high rate of bovine respiratory disease (BRD) should be evaluated for mineral and vitamin deficiencies and supplemented as needed. If not deficient, it should not be expected that supplementation would reduce the rate of BRD in the face of mismanagement.
Evaluation of the Effectiveness of a Commercial Mannheimia (Pasteurella) haemolytica Vaccine in a Commercial Feedlot
Authors: MacGregor Scott , Smith Dudley , Perino Louis J. , Hunsaker Breck D.
Published: March 2023

A single, 2-ml injection of a Mannheimia (Pasteurella) haemolytica bacterin-toxoid was administered subcutaneously to calves on arrival at the feedlot. Calves receiving the bacterin-toxoid had reduced crude mortality. There were no differences in BRD-specific mortality, morbidity or average daily gains (mean days on feed = 179).
Case report
Authors: Maroney Michael J. , Ruegg Pamela L.
Published: March 2023

An epizootic of clinical mastitis was investigated on a dairy farm consisting of 225 cows in Wisconsin, Madison, USA (September 2001). The authors were called to the farm because of a rising bulk tank somatic cell count (BTSCC) and an increased number of clinical mastitis cases refractory to treatment. The BTSCC had peaked at 974?000 in the month preceding the visit. During an initial herd visit, the investigators were able to obtain a herd history, had inspected the facilities, and observed the milking procedure. Management deficiencies were identified which could be contributing to the herd outbreak. Composite culturing of cows experiencing clinical mastitis indicated that Pasteurella multocida was present in 11 of 23 samples. Environmental sampling was unsuccessful in identifying a source for the outbreak. Recommendations for controlling mastitis were adopted and were found to be successful in reducing the spread of mastitis and lowering the BTSCC.
Use of antibiotics to prevent calf diarrhea and septicemia
Authors: Constable Peter D.
Published: March 2023

This article reviews certain studies related to the use of antimicrobial agents to prevent calf diarrhoea and septicaemia, and discusses whether prophylactic administration of antibiotics in neonatal calves is effective and indicated. Orally administered chlortetracycline, oxytetracycline, tetracycline, and neomycin have label claims in the USA for the control or aid in the control of calf diarrhoea caused by bacteria susceptible to the antibiotic. Chlortetracycline and oxytetracycline (0.15 to 6.0 mg/lb [0.32 to 13.2 mg/kg], q 24 h, PO) are efficient in preventing calf diarrhoea and increasing growth rate in milk-fed calves, and chlortetracycline (3 mg/lb [7 mg/kg], q 12 h, PO) is efficient in decreasing mortality when administered to prevent diarrhoea in neonatal calves. There are no antibiotics with a label claim for prevention of calf septicaemia. Because of the apparent lack of efficacy studies for tetracycline and neomycin, and because extra-label use of drugs for routine disease prevention and for increasing weight gain and feed efficiency in calves is prohibited under the Animal Medicinal Drug Use Clarification Act (AMDUCA) of 1994, only oral chlortetracycline or oxytetracycline should be administered to prevent calf diarrhoea.
Use of expected progeny difference (EPD) information to estimate maximum bid price for purchased beef bulls
Authors: Kasari Thomas R. , Kinney Michael R.
Published: March 2023

A pricing model was developed using expected progeny difference information for weaning weight (WW-EPD) to predict the maximum bid price for a bull considered for purchase. The utility of this pricing model should appeal most to veterinarians working closely with their clients on other bull management issues. To complete the pricing model, buyer-specific data were needed for 2 bulls, a reference bull and a bull being considered for purchase (prospect bull). Data input included a base sale price (in $) for the reference bull, the WW-EPD advantage for the prospect bull over the reference bull, expected body weight (in lb), and price (in $/per hundred weight [cwt]) at time of culling for both bulls, and the number of breeding seasons used. Cow-to-bull ratio used, weaning percentage of each calf crop, mean age (months) of calves at weaning, income tax rate (%), discount (interest) rate (%), average price ($/cwt) expected for each calf crop sold, shrink (%), and price slide ($/cwt) were also required to complete the pricing model. Output values generated by the pricing model were initially organized into an income statement summarizing the increased after-tax net income earned from each calf crop produced by the prospect bull over the reference bull for each year of bull use. Income statement information was then transformed into a cash flow statement. Cash flow for each year was transformed into its present value. All present values were summed, and then added to the purchase price used for the reference bull to establish the recommended maximum bid price for the prospect bull. Inaccurate input values will reduce the effectiveness of the pricing model as a tool for informed decision making. Veterinarians who use this pricing model to help their clients value bulls will find that cow-to-bull ratio, number of breeding seasons that a bull is used, and weaned calf crop percentage are the primary factors influencing the premium that can be paid for the prospect bull over the reference bull.
Overview of animal welfare in the US dairy industry
Authors: Garry Franklyn B.
Published: March 2023

Dairy production systems in the United States have changed considerably over the last several decades due to forces that promote economic efficiency of production and to scientific and technological advances that afford opportunities for change. Societal values and concerns about animal wellbeing, and specifically about livestock production systems and their impact on animal wellbeing, have also changed throughout this time. It would be worthwhile for dairy producers and veterinarians to critically evaluate production practices for their impact on the animals. Optimizing animal wellbeing is not only a moral imperative, but should also assure optimal animal productivity. This manuscript attempts to summarize industry changes that impact dairy animal management, and to highlight areas of real or perceived concern about dairy animal welfare that warrant careful attention by producers and veterinarians. For readers who want to review more comprehensive literature on animal welfare in other livestock production industries, this material was originally published as a chapter in the book The Wellbeing of Farm Animals: Challenges and Solutions, GJ Benson and BE Rollin (eds), Iowa State University Press, 2004.
Case report
Authors: Torres-Diaz Roberto O. , Gnad David P. , Walz Paul H. , Chenoweth Peter J.
Published: March 2023

A 13-year-old, 710-kg, Aberdeen Angus embryo donor cow was presented to the Kansas State University Veterinary Medical Teaching Hospital with a two-year history of a slow-growing, uterine mass. Tentative diagnosis of a smooth muscle tumour was made by exploratory laparotomy and uterine biopsy. Surgical excision was considered, but not conducted due to tumour size and location. The cow was euthanized and ova harvested for in vitro fertilization. Laboratory examination indicated that three good quality ova were collected. Definitive diagnosis following postmortem examination was uterine leiomyosarcoma.
Case report
Authors: Gardner C. E. , Nydam D. V. , Ellis R. G. , Kelsey Sonya , McDonough P. L. , Warnick L. D.
Published: March 2023

In the fall of 2001, a large commercial dairy calf and heifer raising operation in New York, USA, suffered an outbreak of acute neonatal diarrhoea. Prior to the outbreak, mortality before weaning was 2.5%, and during the outbreak preweaning mortality reached 10%. Multidrug-resistant Salmonella spp. serogroup C2 (serotype Newport) was recovered from clinically affected calves as well as from many environmental sites, including footbaths. This paper identifies some risk factors, such as low serum total protein, and reviews management protocols that were helpful, as well as those that were not (e.g., footbaths), for controlling transmission of Salmonella spp.
Acute trichomoniasis and sub-optimal bull fertility in a cow/calf herd
Authors: Barling K. S. , Field R. W. , Snowden K. F. , Hoevers J.
Published: March 2023

A beef cow/calf ranch contacted the veterinary teaching hospital concerning low pregnancy rates. The 600-cow herd consisted of three breeding groups of females, with each group being exposed to multiple-sire bull batteries for 90 days (April-June). Each breeding group was palpated for pregnancy approximately 60 days following bull removal from the cows. Pregnancy rates in the groups were 60, 25 and 41%. No abortions had been observed by management during or following the breeding season. Initial work-up found that each group of cows was in adequate body condition for reproduction. A high percentage of the ranch's bull population was positive for culture and polymerase chain reaction for Tritrichomonas foetus. In addition, a high percentage of the bull population failed to pass a breeding soundness examination. Treatment recommendations included culling the entire bull population and replacing it solely with virgin bulls that had passed a breeding soundness examination. Simultaneously, we recommended administration of a T. foetus vaccine to all females, followed by a vaccine booster dose 30 days later. All non-pregnant females were to be placed in separate breeding groups and exposed to the new bull population for 60 days (Dec-Jan). Palpation of non-pregnant females was to be performed 60 days following bull removal. The ranch followed these treatment recommendations. Following bull removal 60-day pregnancy rates were 95%. All replacement bulls passed a breeding soundness examination and were negative for T. foetus by polymerase chain reaction following exposure to the non-pregnant females. Ninety-eight percent of pregnant cows from the original bull exposure (April-June) delivered term calves.
Prevalence of bovine viral diarrhea virus in young purebred beef bulls in Kansas
Authors: Gnad David P. , Walz Paul H. , Sargeant Jan M. , Chenoweth Peter J.
Published: March 2023

Bovine viral diarrhea virus (BVDV) causes severe economic losses in the cattle industry worldwide. To mitigate risk of these losses, BVDV should be considered when formulating beef cattle biosecurity programs. It is important to have accurate prevalence estimates for specific populations being tested when developing risk assessments as part of a biosecurity program. The objective of this study was to determine the prevalence of BVDV infection in young (10 months-two years of age), purebred beef bulls for sale in the state of Kansas. Serum samples from young, purebred beef bulls were submitted to the United States Department of Agriculture (USDA) for brucellosis testing as part of the Kansas state requirements for the sale of breeding bulls. All serum samples (2,520) collected between January 1, 2001 and December 31, 2001 were tested for BVDV using an indirect immunoperoxidase monolayer assay. A total of 17 serum samples tested positive for BVDV, corresponding to a prevalence of 0.67% (95% CI; 0.35-0.99%) in this population. Therefore, although uncommon, young purebred beef bulls may be a source of infection for BVDV.
Assessment of the benefits of Orbeseal®, when used in combination with dry cow antibiotic therapy in three commercial dairy herds
Authors: Cook N. B. , Pionek D. A. , Sharp P.
Published: March 2023

An internal teat sealant containing bismuth subnitrate was used in combination with dry cow antibiotic therapy in a cow-level prospective case-control field trial in three herds with different dry cow management practices. Treated quarters (antibiotic+sealant) had a 59% lower odds of developing a new dry period infection at 1-3 days-in-milk (DIM) than control (antibiotic only) quarters (P<0.001). Herd-level variation in new intramammary infection (IMI) and mastitis treatment rates during the first 100 DIM were observed. Greatest benefits from internal teat sealant use were documented in herds with the highest rates of new IMI during the dry period, and for environmental streptococci. Economic benefit accrued from differences in the timing of treatment for mastitis was estimated to be $5.38 per cow in the herd.
Particle size evaluation and its association with feed intake, milk yield and chewing activity in mid-lactation Holstein cows
Authors: Melendez P. , Back N. , Donovan A. , Lanhart S.
Published: March 2023

The objective of this study was to determine the associations among fresh and residual fractions of a total mixed ration (TMR), milk production and ruminating proportion of mid-lactation Holstein cows. During March 2002, daily representative TMR samples were collected at 8:00 a.m. from freshly delivered feed on a Holstein dairy in Florida. A sample of the residual feed (weigh-back) was collected at 7:30 a.m., corresponding to the weigh-back of the previous day. Samples were processed daily within 15 minutes of collection. Feed intake (as-fed), maximum and minimum temperatures of the day and individual milk yield were recorded daily. Each day, four hours after the 8 a.m. feeding (12 noon), numbers of cows ruminating and eating were counted. Particle size was evaluated using the Penn State particle size evaluator with three sieves. Dry matter (DM) content of each fraction was evaluated by using a microwave technique. Regression models for different outcomes were conducted. Models were developed using fractions as-fed and as DM basis. Differences in DM content between coarse and medium size were not statistically significant. For all models, predictors were the same for both as-fed basis and DM basis. For dry matter intake (DMI), the only significant predictor was the minimum daily temperature, with a negative association. No variable was associated with weigh-back coarse fraction. However, when coarse and medium fractions were pooled as one fraction, maximum temperature of the day and DMI were predictors of this new outcome. For medium weigh-back fraction, significant predictors were fresh medium fraction proportion and DMI. Dry matter intake was negatively associated with medium fraction proportion. The proportion of cows ruminating was positively related to the proportion of cows eating four hours after fresh feed was placed on the feed bunk. Milk yield was negatively associated with the medium fresh fraction proportion of the day before.
Estimating the effects of animal health on the performance of feedlot cattle
Authors: Irsik Max , Langemeier Michael , Schroeder Ted , Spire Mark , Roder Joseph Deen
Published: March 2023

This study was conducted to determine the effect of animal health on the performance of feedlot cattle. Multiple regression models were developed to aid in the performance analysis for feed conversion, average daily gain, added cost and cost of gain. Results of this study showed that for each percentage increase in mortality in a pen of cattle, the feed conversion ratio increased by 0.27 pounds (0.12 kg), the average daily gain decreased by 0.08 lb (0.036 kg) per day and added costs increased $1.00 per head. For each percentage increase in the treatments for a pen of cattle, death loss increased by 0.143%. A 10% treatment rate would equate to a 1.7% death loss. These data should be useful in estimating the performance of fed cattle. This study confirmed and quantified the negative effect of adverse health on the performance of fed cattle.
Clinical trial to determine the productivity impact of milk urea nitrogen reports
Authors: Arunvipas P. , VanLeeuwen J. A. , Doohoo I. R. , Keefe G. P. , Lissemore K. D.
Published: March 2023

A clinical trial was conducted to determine the perceived and actual utility of milk urea nitrogen (MUN) notification and interpretation as a tool for monitoring protein and energy imbalances in dairy cows. Based on MUN results during the summer of 2001, 50 farms with high MUN values and 30 with low values were randomly allocated to become either intervention or control farms. From January to November 2002 (the trial period), intervention included monthly notification of individual cow MUN results, interpretation of abnormal average MUN values in subgroups of cows based on parity and days-in-milk, and suggestion of possible nutritional reasons for the abnormal MUNs. Intervention farms responded to a survey regarding report utilization, subsequent feed changes and perceptions of MUN testing. Control farms received the individual cow MUN results, but no additional interpretation. No significant differences in average MUN or standardized milk production between intervention and control farms were seen during the last three months of the trial (the outcome period). However, in herds making a feed change in response to MUN notification and interpretation (71% of intervention herds), milk production increased 2.4 lb (1.1 kg)/cow per day in the month after the feed change when compared to randomly selected herds not making a feed change during the same time period. Most dairy producers receiving the MUN notification and interpretation reports felt they knew how to use MUN reports after the trial, and felt that MUN testing was at least somewhat useful as a nutritional tool.
Effect of different castration methods on growth performance and behavior responses of postpubertal beef bulls
Authors: Rust R. L. , Thomson D. U. , Loneragan G. H. , Apley M. D. , Swanson J. C.
Published: March 2023

Fifty mixed-breed, 790 lb (359 kg) preconditioned bulls were utilized to examine the effect of different castration methods on animal performance and behavior response. Cattle were blocked by weight and randomly assigned to one of five treatments: non-castrated control (CNT); castrated using high-tension rubber bands (BND); castrated using high-tension rubber bands with lidocaine local anesthesia (BNDL); castrated surgically (SURG); and castrated surgically with lidocaine local anesthesia (SURGL). Cattle were fed individually for 28 days post-castration. Castrated cattle tended to have lower dry matter intake (DMI) than CNT cattle throughout the study (P=0.12). BND/BNDL cattle had higher DMI than SURG/SURGL cattle during the first week post-castration (P=0.04), however, SURG/SURGL cattle had higher DMI than BND/BNDL cattle during the last week of the study (P=0.05). Castrated cattle had lower average daily gain (ADG; P<0.01) and gain efficiency (GE; P<0.01) than CNT cattle. SURG/SURGL cattle had more favorable ADG (P<0.01) and GE (P<0.01) than BND/BNDL cattle during the study. There were minimal to no behavioral differences observed post-castration between treatment groups. Use of local lidocaine anesthesia had no effect on performance, post-castration behavior or vocalization during castration, regardless of castration method utilized. A positive correlation was found between scrotal circumference and vocalization (P=0.05); however, the correlation between body weight and vocalization was not significant.
Case report
Authors: Melendez P. , Rae O. , Risco C.
Published: March 2023

An obese four-year-old Brangus bull was presented with a swollen protruding penis and enlarged pendulous abdomen. Azotemia, urinary bladder rupture and urolithiasis were diagnosed; the bull was euthanized. Calculi were composed of magnesium ammonium phosphate (struvite). A later visit to the ranch found that bulls were overfed concentrate ration, magnesium and phosphorus. Nutritional changes were recommended, and no further cases of urolithiaisis were reported.
Field study comparing fecal egg count reduction, weight gain and product safety in stocker cattle treated with either moxidectin or ivermectin with clorsulon
Authors: Yazwinski T. A. , Tucker C. A. , Powell J. G. , Reynolds J. , Johnson Z. B. , Moore J. J. , Prewett C. , Griffin D. , Haller B.
Published: March 2023

This study was conducted to assess effectiveness, safety and benefit of injectable moxidectin compared to an injectable ivermectin-clorsulon combination. A total 2,022 stocker calves maintained on 11 Arkansas and Missouri cattle farms were randomly and evenly allocated on each farm into either the moxidectin (MXD) or ivermectin-clorsulon (IC) group. No negative controls were utilized in the study. All treatments were administered on a unique day 0 for each farm. Herd sizes ranged from 54 to 544. Naturally infected mixed breed bull, steer or heifer calves, weighing from 241 to 810 lb (110 to 368 kg) on day 0, were used in the study. On days 0, 50 (approx) and 100 (approx), each animal was weighed, and fecal samples were obtained from 20% of the animals (same animals on each sample day) for determination of fecal nematode egg counts and coproculture larvae identification. Both products were easily administered and no adverse effects were noted following administration of either drug. Weight gain from day 0 did not vary significantly between treatment groups at either of the post-treatment sampling dates. In addition, sex by treatment interaction was not significant (P<0.05), as analyzed on those farms that had both male and female cattle in the study population. On day 0, no significant differences were found between treatment groups for strongyle eggs per gram of feces (EPG) counts or coproculture larvae percentages. For days 50 and 100, EPG counts for MXD-treated calves were significantly lower than those for IC-treated calves (P<0.05). Day 0 coproculture data indicated that the primary nematode parasites contributing to the fecal egg counts were Cooperia, Haemonchus and Ostertagia. On days 50 and 100, MXD-treated animal coprocultures yielded higher larvae percentages of Cooperia than did the IC-treated animal coprocultures (P<0.05), as well as significantly lower Ostertagia and Haemonchus larvae percentages. Egg count and coproculture results suggest that both parasiticides were most limited in their ability to control Cooperia, but greater post-treatment egg production by Cooperia, Ostertagia and Haemonchus occurred in calves treated with IC compared to those in the MXD group.
Case report
Authors: Dubuc Jocelyn , DuTremblay Denis , DesCoteaux Luc , Baril Jean , Bagg Randal , Vessie Gordon H.
Published: March 2023

Lactating dairy cows were accidentally fed monensin at a dose of 32.7 g per ton (36 ppm) of feed for three weeks. This resulted from a mixing error when monensin was added to the mineral premix, as well as an error in the amount of mineral fed to the lactating cows. A decrease in dry matter intake was noticed during the first three days following the mixing error. Bulk-tank milk fat percentage decreased by 0.6, but daily milk production increased by 6.9 lb (3.1 kg)/cow/day during this period, and for an additional two weeks. A residual effect on milk production and fat percentage was observed for three weeks after monensin intake returned to the prescribed dosage of 14.5 g per ton (16 ppm). This residual effect was more pronounced during the first week following resumption of the prescribed intake of monensin.
Body Temperature and White Blood Cell Count in Postpartum Dairy Cows
Authors: Wagner S. A. , Schimek D. E. , Cheng F. C.
Published: March 2023

The objectives of this study were to evaluate rectal temperature as a diagnostic tool in postpartum dairy cows and to compare body temperature and white blood cell counts in cows that remained healthy with those that became ill. Fifty Holstein dairy cows had complete physical examinations every four hours and a complete blood count once daily for the first 10 days after calving. Illness was defined as a rectal temperature of at least 104.5Â°F (40.3Â°C) in the absence of other clinical signs, or a clinical sign of illness other than increased temperature. Fifteen cows were diagnosed with illness and 35 remained healthy throughout the 10-day study period. No difference between mean rectal temperatures of cows that became ill and cows that remained healthy was found. Among cows that remained healthy, 23 (66%) had a rectal temperature of at least 103.1Â°F (39.5Â°C) at least once, 17 (49%) had a rectal temperature of at least 103.5Â°F (39.7Â°C) at least once and six (17%) had a rectal temperature of at least 104Â°F (40Â°C) at least once during the study period. Over the first three days after calving, mean total white blood cell counts and neutrophil counts were higher in healthy cows than in cows that became ill. Because rectal temperatures were frequently elevated in healthy postpartum cows, it was concluded that rectal temperature has low specificity for diagnosing illness in postpartum dairy cows in the absence of other clinical signs.
Effect of viral respiratory vaccine treatment on performance, health and carcass traits of auction-origin feeder steers.
Authors: Bryant T. C. , Rogers K. C. , Stone N. D. , Miles D. G.
Published: March 2023

A total of 3,147 auction-origin steers were used to compare the effects of three different virus vaccines on performance, health, carcass traits and economic return in a commercial feedlot. Vaccine products compared were PyramidÂ® 5 (Fort Dodge Animal Health, Overland Park, KS), Bovi-Shield GoldÂ® 5 (Pfizer Animal Health, New York, NY) and Bovi-Shield GoldÂ® IBR-BVD. Steers vaccinated with Pyramid 5 (PYR5) vaccine had 3.8% ( P =0.09) better feed conversion than those vaccinated with Bovi-Shield Gold IBR-BVD (BOV3) vaccine when calculated on a live-weight basis, but similar to steers in the Bovi-Shield GoldÂ® 5 (BOV5) group. On a carcass-weight basis, feed conversion was 3.6% better ( P =0.09) in the PYR5 treatment group compared to steers in the other treatment groups. No differences ( P >;0.10) in carcass traits were noted among the three treatment groups. The morbidity rate due to bovine respiratory disease was 11% lower ( P =0.09) in steers vaccinated with PYR5 compared to those vaccinated with BOV5, and the relapse rate was 22% lower ( P =0.04). Combined treatment and railer (culling) costs were $8.81/head and $7.56/head lower in the PYR5 group than in the BOV5 and BOV3 steers, respectively. Mortality costs did not differ among treatments ( P =0.52).
Case report
Authors: Buczinski Sebastien , Badillo Mauricio
Published: March 2023

A two-year-old Holstein heifer with clinical signs of right-sided heart failure which appeared two weeks after calving, including tachycardia and muffled heart sounds was presented. Pericarditis was diagnosed using echocardiography. Pericardiocentesis revealed hemorrhagic pericardial fluid and cytologic findings were compatible with idiopathic hemorrhagic pericarditis. Pericardial drainage and lavage was suggested, but the owner refused. A rumen magnet was administered to the cow, and penicillin was given for seven days. Two months after the initial diagnosis, clinical examination of the cow was normal, including normal echocardiographic findings.
Survey of Southern Arizona Calves for Persistent Infection with Bovine Viral Diarrhea Virus
Authors: McDaniel M. D. , Collins J. K. , Duff G. C. , Cuneo S. P. , Glock R. D. , Campbell J. W.
Published: March 2023

This study was conducted to determine the prevalence of persistent infection (PI) with bovine viral diarrhea virus (BVDV) in dairy and beef calves in southern Arizona. Formalin fixed skin biopsies of ear from the animals were used to perform immunohistochemistry (IHC). A total of 3,010 dairy bull calves, ranging in age from one day to approximately 14 days, were sampled and 15 PI calves were identified, giving an apparent prevalence of 0.49%. Range beef calves ranging from newborn to approximately 12 months were also sampled. One PI animal was identified out of 1,096 calves tested. Dairy calves testing positive for BVDV at the first sampling were retested using IHC and virus isolation at two-week intervals to confirm PI status.
Current challenges of the management and epidemiology of bovine anaplasmosis
Authors: Kocan Katherine M. , De la Fuente Jose , Step Douglas L. , Blouin Edmour F. , Coetzee Johann F. , Simpson Katharine M. , Genova Suzanne G. , Boileau Melanie J.
Published: March 2023

Bovine anaplasmosis, caused by the intracellular rickettsia Anaplasma marginale, is endemic in several areas of the United States and has continued to impact cattle production. While considerable research has been done over the past several decades, control strategies for anaplasmosis have advanced minimally since the first anaplasmosis vaccine was marketed in the US in the 1960s. However, these research findings have continued to contribute to our overall understanding of the complexity of bovine anaplasmosis. With the advent of molecular biology, host/pathogen interactions are currently better defined and the classification of Anaplasma has been reorganized to include several organisms in addition to those that are host-specific for ruminants. In this review, the current status of anaplasmosis is discussed with the aim of providing insight to bovine practitioners on the future challenges for the management, diagnosis, and control of bovine anaplasmosis. This review focuses on updated information on the classification of the genus Anaplasma and related organisms, the developmental cycle of A. marginale in cattle and ticks, the role of male ticks in transmission of anaplasmosis, the diversity of A. marginale strains, the wildlife reservoirs of A. marginale, and the potential influence of climate change on the epidemiology of this serious disease. A second review will follow which focuses on current issues related to diagnosis and control of bovine anaplasmosis. Overall, the goal of these reviews is to provide an understanding of the current status of research and knowledge of bovine anaplasmosis and provide veterinarians answers to frequently asked questions.
Tetanus in cattle
Authors: Garber Jonathan R. O. , Smith Billy I.
Published: March 2023

Tetanus (Clostridium tetani infection) is a potentially life-threatening neurologic disease affecting cattle. Clinical signs of tetanus are frequently unrecognized until advanced stages of the disease, when treatment and management of affected animals are difficult and prognosis is relatively poor. This case report demonstrates the successful early diagnosis and subsequent management of wound tetanus in a 13-month-old Holstein heifer. Primary clinical signs that led to an accurate diagnosis and early treatment included stiff gait, erect tail, and prolapsed nictitans. Intensive medical management yielded a relatively rapid improvement in clinical signs. The heifer calved and entered the lactating herd. Practitioners that observe the previously mentioned clinical signs in cattle should consider tetanus as a primary differential diagnosis and initiate aggressive medical management.