bluuebunny/crossref_metadata_2025 huggingface dataset:
Reproductive Applications of Ultrasound in the Cow
Authors: Jones A. L. , Beal W. E.
Published: March 2023

During the past decade portable ultrasound units that provide excellent image quality have become available to veterinary practitioners. The use of transrectal ultrasonography for evaluation of reproductive structures in cattle extends and enhances the diagnostic capabilities of practitioners beyond the traditional use of palpation per rectum. Ultrasonography of ovaries enables more consistent differentiation of ovarian follicles and corpora lutea. Accurate counting of follicles and precise measurement of follicles or corpora lutea is possible. Sequential monitoring of ovarian structures enables the user to characterize ovarian follicular waves, to identify dominant follicles and to detect ovulation. Images can be used to identify, objectively measure and to characterize the quality of a corpus luteum. Ultrasonography is also a valuable tool for identification of abnormal (cystic) luteal and follicular structures. Pregnancy diagnosis can be performed using ultrasound by day 19 to 24 post-breeding and fetal viability can be verified by visualization of a fetal heartbeat. Aging embryos and fetuses between days 20 and 100 of gestation can be facilitated by measuring crown-rump length (20-50 days) or the diameter of the head or trunk (50- 100 days). Sexing of bovine fetuses is accomplished by visualizing the genital tubercle (penis) and scrotum in males or by the lack of male genetalia and the presence of the genital tubercle (vulva) in females. Sex determination is most practical between days 60 and 85 of gestation. Like other diagnostic tools, ultrasound has limitations. Skill of the ultrasound technician in capturing clear images, differentiating anatomical orientations and interpreting ultrasound images is essential. The effective use of ultrasound technology enhances diagnostic capabilities and increases the services offered by veterinarians.
Case Report - Johne’s Disease
Authors: Manning Elizabeth J. B. , Augenstein Monica , Collins Michael T. , Nelson Kathryn M.
Published: March 2023

This is the first report of intrauterine Mycobacterium paratuberculosis transmission from a bovine embryo recipient to the resultant calf. The recipient was ELISA and fecal culture test-negative before embryo placement, but became ELISA-positive during the pregnancy. Johne’s disease was confirmed at necropsy subsequent to Caesarean section. Her embryo transfer calf was diagnosed with Johne’s disease two years later. Strict research biosecurity protocols under which the embryo transfer calf was raised eliminated routes of post-natal exposure to M. paratuberculosis. The recipient cow had been purchased from a herd at risk for M. paratuberculosis infection for which no Johne’s disease surveillance was performed.To minimize the likelihood of purchasing an infected recipient cow or obtaining M. paratuberculosis- contaminated colostrum and thus jeopardizing valuable embryos, recipient and colostrum donor purchases should be made from a source herd with no or low, whole- herd Johne’s disease test prevalence. The risk of purchasing an animal with M. paratuberculosis infection can be better assessed with whole-herd infection prevalence data than with test results for a single animal only.
Case report
Authors: Villar David , Larson David J. , Janke Bruce H. , Schwartz Kent J. , Yaeger Michael J. , Carson Thomas L. , Blaylock Randy
Published: March 2023

An outbreak of urolithiasis occurred in a small beef cattle feedlot feeding a total mixed ration containing cracked com, com gluten, gluten balancer, hay and di- atomaceous earth. A1100 lb (500 kg) steer was presented to the Iowa State University Veterinary Diagnostic Laboratory for euthanasia and necropsy. Clinical signs included frequent tenesmus, evidence of abdominal pain, regurgitation and labored breathing. Serum chemistry revealed elevated BUN (160 mg/dl), creatinine (28.9 mg/ dl), creatine kinase (2253IU/L), and an inverted calcium- to-phosphorus ratio of 0.8. At necropsy, complete obstruction of the urethra with calcium phosphate (apatite) calculi was present. Based on the clinical pathology and extensive tissue damage in this animal, the prognosis was poor if surgical treatment had been elected.Analysis of the total mixed ration revealed a calcium-to-phosphorus ratio of 1:1. This case highlights the importance of a prompt diagnosis of urinary calculi in symptomatic animals, and evaluation of the ration for possible mineral imbalances.
Urinary tract disease, weight loss and death possibly related to winter browsing of a shrubby plant (Cistus salviifolius) in three herds of Portuguese beef cattle
Authors: Lima Miguel Saraiva , Peleteiro Maria Conceicao , Malta Manuel , Pais A. Brito , Hjerpe Charles A.
Published: March 2023

Four outbreaks of fatal urinary tract disease in beef cattle were studied on 3 farms in Southern Portugal between 1998 and 2000. The Portuguese Mertolenga breed appeared to be at increased risk. 93% of deaths occurred in animals aged 4 years or older. No cases were observed in animals less than one year of age. Outbreaks of disease, which developed from January through May, were associated with inadequate pasture growth during December through February, a result of either unseasonal cool, rainy and overcast, or dry winter weather. Circumstantial evidence suggested that the disease was related to browsing a bushy, non-deciduous, perennial range plant, Cistus salviifolius (sage leaf rock rose), during periods of nutritional deprivation. Dysuria was observed in nearly all affected animals. On rectal and necropsy examinations, the urinary bladder was greatly distended. The bladder wall was thickened and oedematous in 44% of cases necropsied. In the early stages of disease, a variable proportion of affected cattle showed signs of photophobia, and a few eventually became blind and had severe bilateral keratitis and complete corneal opacity. Chronic cases lost considerable weight. Survivors recovered slowly, taking 4 to 12 months or even longer. The course of fatal disease ranged from less than 2 weeks to more than 5 months. The combined mean morbidity, mortality, and case fatality rates for all outbreaks (in straightbred Mertolenga herds) were 26, 11, and 43%, respectively.
Flowchart for evaluating dairy cow freestalls
Authors: Nordlund Ken , Cook Nigel B.
Published: March 2023

A flow chart system has been developed to evaluate dairy freestalls. It details 4 critical points: adequate surface cushion, adequate body resting space, lunge room for head thrust and an unobstructed bob-zone, and adequate height below and behind the neck rail. Surface cushion is considered to be the most important factor in determining stall usage. If the stall allows a full forward lunge, the configuration of the stall divider has little importance. If side lunge is required, the exact height of the divider rails is critical. Several clinical problems that result from inadequate stalls are discussed.
Bovine viral diarrhea (BVD)
Authors: Larson R. L. , Grotelueschen D. M. , Brooks K. V. , Hunsaker B. D. , Smith R. A. , Sprowls R. W. , MacGregor D. S. , Loneragan G. H. , Dargatz D. A.
Published: March 2023

Characteristics of bovine viral diarrhoea virus (BVDV), such as its genetic diversity and ability to induce a persistently infected (PI) carrier state, make its control a challenge. A systematic control programme that utilizes diagnostic testing strategies to identify PI cattle, vaccination to increase fetal protection from infection, and biosecurity to reduce the risk of exposure to infected animals is necessary for control of BVD. The primary reservoir for BVDV is PI cattle. If a herd has had recently confirmed PI calves, or if the history strongly suggests the presence of PI calves, then all calves, replacement heifers, bulls, and nonpregnant dams without calves should be tested for PI status. Positive cattle should be removed prior to the start of breeding. Because of the low prevalence of herds with PI animals, whole-herd screening protocols for herds at low risk for PI cattle may not be justified. Several strategies short of whole-herd screening can be employed to monitor herds for the presence of PI cattle. Biosecurity to reduce the risk of exposure to BVDV should also be implemented. Replacement heifers and bulls should be tested and confirmed PI-negative prior to the start of breeding. If a pregnant animal is purchased, she should be segregated until both dam and calf are confirmed PI-negative. Fence line contact with neighbouring herds should be avoided during early gestation unless they also have a strict biosecurity programme in place. Vaccination to reduce the risk of fetal infection in the event of exposure to a BVDV-shedding animal is an integral part of a biosecurity programme.
Training Spanish-speaking livestock workers
Authors: Roman-Muniz Ivette N. , Van Metre David C. , Hirst Heather L. , Garry Franklyn B.
Published: March 2023

In this decade, Hispanics are projected to be the fastest growing minority group in the USA. With greater numbers of non-English-speaking, foreign-born workers employed in the animal agricultural industries, language and cultural barriers may exacerbate pre-existing shortcomings with personnel management and worker training on certain operations. Improved worker training methods have recently been identified by Colorado dairy producers as a priority issue. However, there appears to be much variability in the Colorado dairy industry in the method of delivery of such training, its nature and scope, and its efficacy in preparing workers for their jobs. Veterinarians can play a key role in improving worker training on livestock operations by assuming a greater role as trainers of the dairy workforce, particularly in regard to skills that involve direct interactions with animals, such as sick cow identification and treatment, calving management and milking parlour procedures. Cultural sensitivity, bilingual teaching aids, hands-on demonstrations, consistent follow-up and retraining, outcome assessment and patience are necessary to maximize the benefit of such educational initiatives.
Effect of two dosage levels of doramectin on health, growth performance and carcass characteristics of finishing beef steers
Authors: Rogers Karen C. , DuBois William R. , Portillo Thomas A. , Miles Delbert G.
Published: March 2023

A total of 3446 crossbred Mexican-origin steers (average 625 lbs/284 kg) were utilized to determine the effect of administering doramectin at label-dose (full-dose, 200 mcg/kg body weight; 1 ml/110 lbs) vs. half-label dose (half-dose, 100 mcg/kg body weight; 1 ml/220 lbs) on health, growth performance and carcass characteristics of finishing beef steers. Health parameters, growth performance and carcass quality grade did not differ between treatments. However, there was a significant difference in the proportion of carcasses classified as USDA yield grades (YG) 2, 3 and 4. A higher proportion of carcasses in the full-dose treatment were scored YG 2 (P<0.0001), and a higher proportion of carcasses in the half-dose treatment were scored YG 3 (P=0.0014) and YG 4 (P=0.0112), suggesting steers treated with the full-dose treatment were leaner. These results indicate that there is no economic advantage to using the full dose (200 mcg/kg body weight) of doramectin in beef cattle.
Comparison of serological responses when modified-live infectious bovine rhinotracheitis virus vaccine and Mannheimia haemolytica bacterin-toxoid are administered with needle-free versus conventional needle-based injection in yearling feedlot steers
Authors: Hollis Larry C. , Smith John F. , Johnson Bradley J. , Kapil Sanjay , Mosier Derek A.
Published: March 2023

A total of 111 yearling feedlot steers were vaccinated with 5-way modified-live virus vaccine and Mannheimia haemolytica (MH) bacterin-toxoid, utilizing either needle-free or conventional needle-and-syringe injection techniques. Blood samples were collected from all steers at the time of vaccination and 21 days later, and serum was analyzed for antibody titers to infectious bovine rhinotracheitis (IBR) virus and M. haemolytica (MH) leukotoxin. Serological response to the IBR viral fraction of the 5-way viral vaccine was significantly higher (P=0.001) on day 21 following administration with needle-free injection, compared to conventional needle injection. Serological responses to the MH supernatant and cell-associated antigens were not statistically different (P=0.06) on day 21 following administration with needle-free injection, compared to conventional needle injection.
Comparison of serological responses when modified-live infectious bovine rhinotracheitis virus vaccine, Mannheimia haemolytica bacterin-toxoid and Leptospira pomona bacterin are administered with needle-free versus conventional needle-based injection in Holstein dairy calves
Authors: Hollis Larry C. , Smith John F. , Johnson Bradley J. , Kapil Sanjay , Mosier Derek A.
Published: March 2023

A total of 104, five- to ten-month old Holstein heifers and steers were blocked by age within sex-group, randomized to treatment and vaccinated with 5-way modified-live virus vaccine, Mannheimia haemolytica bacterin-toxoid and 5-way Leptospira bacterin utilizing either needle-free or conventional needle-and-syringe injection techniques. Blood samples were collected from all animals at the time of vaccination and 21 days later, and the serum analyzed for antibody titers to infectious bovine rhinotracheitis (IBR) virus as the indicator of serological response to the 5-way viral vaccine, Mannheimia haemolytica (MH) leukotoxin, and Leptospira pomona (LP) as the indicator of serological response to the 5-way Leptospira bacterin. On day 21 the serological response of heifers to the IBR fraction of the 5-way viral vaccine, MH bacterin and LP fraction of the 5-way Leptospira bacterin were not significantly different between routes of administration. On day 21 the serological response of steers to the IBR fraction of the 5-way viral vaccine and MH bacterin was significantly higher for the needle-free route of administration, while the serological response to the LP fraction was not significantly different between routes of administration.
Frequent changing and rinsing of drinking water buckets improved performance of hutch-reared Holstein calves
Authors: Wiedmeier R. D. , Young A. J. , Hammon D. S.
Published: March 2023

There is often great variation in the cleanliness of drinking water provided to hutch-raised calves. Due to the relationship between dry matter intake and water intake, low water quality in the calf hutch could reduce feed intake and daily gain, and possibly affect health status of the calves. The objective of this study was to compare the performance of hutch-reared calves when drinking water containers were changed/rinsed with decreasing frequency. For three consecutive years, 24 Holstein bull calves (2-7 days of age) were purchased each year from a single commercial dairy. Calves were purchased in four sets of six calves each in September, December, March and June of each year. Calves remained in the hutches for 60 days, receiving milk replacer twice daily. A concentrate mix was available at all times. Of the six calves in each set, two had their drinking water buckets rinsed daily, two were rinsed at 7-day intervals and two at 14-day intervals. Average daily gain (ADG) of calves was measured during the 60-day period while in hutches, and through a subsequent 100 to 110-day post-weaning feeding period. The frequency of changing/rinsing drinking water buckets affected ADG of calves while in the hutches: daily, 1.55 lb (0.70 kg)/day; 7-day, 1.48 lb (0.67 kg)/day; 14-day, 1.40 lb (0.64 kg)/day. All means were different (P<0.05). These differences in ADG carried over through the post-weaning period: daily, 3.12 lb (1.42 kg)/day; 7-day, 3.01 lb (1.37 kg)/day; 14-day, 2.90 lb (1.32 kg)/day. The daily and 14-day treatments were different (P<0.05), while the 7-day treatment was intermediate. Calves assigned to the daily and 7-day changing/rinsing regimen required a similar number (1.25) of medical treatments while in the hutches (P>0.05). When drinking water buckets were changed/rinsed at 14-day intervals, calves required 1.75 medical treatments, an increase of 40%. Calves on the 14-day regimen were 2.48 (95% CI: range 1.32 to 4.68) times more likely (P<0.01) to receive more than one treatment, compared to calves on daily and 7-day changing/rinsing regimens. Thus, a seemingly minor management practice such as frequency of changing/rinsing drinking water buckets in calf hutches can have an impact on calf performance and health.
Impact of a progesterone-releasing intravaginal device on plasma progesterone levels in lactating dairy cattle
Authors: Keefe Greg , Squires E. James , Walsh Rob , Wilson Jeffrey B. , Leslie Ken E.
Published: March 2023

Plasma progesterone (P4) levels were assessed by radioimmunoassay in lactating dairy cows treated with a progesterone-releasing intravaginal device (PRID). Group A cows (N=6) received no treatment. PRIDs were administered to Group B1 (N=3) on day 25 after the first observed estrus (Day 0) and to Group B2 (N=3) on day 31, and were withdrawn 14 days after administration. Blood was collected daily from day 0 until 56 hours after withdrawal of the PRID (Group B), or on alternate days until a second estrus was observed (Group A). The area under the P4 curve (AUC) did not differ for Groups A and B pre-insertion of the PRID, but was significantly greater for Group B post-insertion. The AUC in Group B cows was significantly greater post-insertion than pre-insertion, but AUC did not differ in Group A cows for these study days. Maximum P4 was significantly greater in Group B1 post-insertion than pre-insertion. Results of this study are consistent with clinical studies demonstrating the efficacy of the PRID in estrus synchronization and treatment of infertility, and support the hypothesis that these effects are due, at least in part, to modulation of circulating progesterone levels.
Surgical removal of a mummified fetus via colpotomy
Authors: Hopper Richard , Hostetler Douglas , Smith Jack , Christiansen David
Published: March 2023

This article reports on the use of colpotomy on three cows (Jersey, Holstein, and Hereford) referred at a Animal Health Centre in Mississippi, USA, diagnosed with mummified fetus.
Effects of feeding high manganese rice straw on the mineral status of beef cattle
Authors: Nader G. A. , Doyle S. P. , Connor J. M. , Maas J.
Published: March 2023

The objective of this study was to determine the effects of feeding rice straw containing high concentrations of manganese (Mn) to beef cattle on liver Mn concentration and its potential to interfere with other minerals. Open, crossbred cows (N=12) in good health were randomly assigned to one of three treatment group diets: oat hay (control), rice straw containing 550 ppm Mn and rice straw containing 770 ppm Mn. High quality alfalfa hay was supplemented at the same amount to each group to ensure adequate energy and protein intake. Blood, serum and liver samples were taken from each animal at day 0, 49 and 93 and analyzed for trace mineral and heavy metal content. Liver Mn concentrations for the group receiving 770 ppm Mn rice straw were significantly higher than for the control group at both day 49 and day 93 (P<0.05). Liver Mn concentrations for the 550 ppm Mn group were significantly higher than for the control group at day 93 (P<0.05). Liver Mn concentrations among the two rice straw treatments were not significantly different from each other. Serum sodium (Na) levels in cows fed the 770 ppm Mn rice straw were significantly higher than the animals fed 550 ppm rice straw at day 49 (P<0.05); however, there appeared to be no significant difference at day 93. There was no significant difference among treatment groups for other trace mineral and heavy metal concentrations. While it appeared cattle fed rice straw maintained higher liver Mn concentrations relative to control cattle, these concentrations were within the reference range of 2-6.5 ppm. There were no significant differences among treatment groups for average daily gain. No practical impact on the mineral status of cattle fed high Mn rice straw was observed over the 93-day period.
Update on the USDA National Animal Identification System (NAIS) program
Authors: Spire Mark F.
Published: March 2023

The National Animal Identification System proposed and under development by the USDA-APHIS is a comprehensive program designed to provide rapid response following the introduction of a foreign animal disease (accidental or intentional), the discovery of an emerging pathogen or within the framework of existing regulatory programs for currently known domestic animal diseases. It is being planned as a three-part voluntary programme: premises registration, individual or group/lot animal identification and animal movement tracking. The premises and animal identification components of the program fit well with other USDA programs, particularly the Agricultural Marketing Service source and age verification programme, for use by producers for value discovery in animals entering marketing channels.
AABP Association and Conference News
Authors: American Association of Bovine Practione
Published: March 2023

Description and highlights of the the Annual Conference of the American Association of Bovine Practitioners (39th : 2006), officers, district news, events, awards, and other news.
Feedyard manager and veterinarian responses to a Delphi-like feedyard biosecurity survey
Authors: Brandt Aric W. , Sanderson Michael W. , DeGroot Brad D. , Thomson Daniel U.
Published: March 2023

A Delphi-like survey series was used to gain knowledge about feedyard biosecurity and security from feedyard managers and feedyard veterinarians. A panel of managers and a panel of veterinarians were selected after being recommended as experts in the industry. Three rounds of the same survey were used to gather consensus opinion from each expert panel about perceived disease risks and mitigation strategies. Both groups were given the same survey, with two additional questions about domestic and international terrorists asked of veterinarians. Results showed veterinarians and managers have very similar views on the likelihood of disease caused by terrorism, natural introduction, or accidental introduction, and on the importance of on-site security. Both groups agreed that foot-and-mouth disease virus (FMDV) or toxins would be the most likely agents to be introduced by a terrorist. Respondent groups disagreed on the importance of preventative products, disease transmission control and environmental control. Most differences can be attributed to veterinarians placing less importance on the aforementioned categories when considering likely routes of introduction for diseases considered in the survey. Difference in awareness of these issues is significant because veterinarians are pivotal in educating feedyard staff members about prevention of disease entry and transmission.
Failure to eliminate the Anaplasma marginale carrier state in beef cows following multiple treatments with long-acting injectable oxytetracycline
Authors: Wallace Justin O. , Hollis Larry C. , Reinhardt Chris D. , Coetzee Johann F. , Renter David G. , Llewellyn Donald , Marston Twig T.
Published: March 2023

Thirty-four multiparous beef cows naturally infected with Anaplasma marginale and confirmed as both seropositive and polymerase chain reaction (PCR) positive for the organism were randomized to treatment. Five cows served as untreated controls, and 29 were treated three times at three-day intervals with a long-acting oxytetracycline formulation at a dose of 10 mg/lb (22 mg/kg). On day 14, 100% of control cows and 90% of treated cows were found to have A. marginale present by PCR testing. All control cows and 86% of treated cows were found to have A. marginale present by PCR testing on day 74. PCR results suggest that utilization of a three-dose regimen of injectable long-acting oxytetracycline at three-day intervals was not effective for eliminating the carrier state of A. marginale from naturally infected animals.
Sexed semen
Authors: Fetrow John , Overton Mike , Eicker Steve
Published: March 2023

The advent of commercially available sexed semen raises issues about its proper use and economic value on dairy farms. Use of sexed semen solely to produce more female offspring, without regard to genetic merit, is not likely a profitable strategy under most commercial dairy management conditions. Sexed semen may have some value for reducing the rate of dystocia on a dairy, but the impact is small per unit of semen (one dollar or less). Use of sexed semen in virgin heifers may be most fruitful, reserving its use for heifers with the best genetics. This strategy requires good information on the genetic merit of young heifers, and the optimal extent of use depends on many economic variables. The opportunity for economic gain assumes that genetic merit of bulls used for sexed semen breeding is no worse than bulls used for conventional artificial breeding. Economics of using sexed semen technology are considered in this paper.
Factors affecting the sale price of bulls consigned to a graded sale
Authors: Irsik Mark , House Amanda R. , Shuffitt Mark R. , Shearer Jan R.
Published: March 2023

Selection or replacement of a herd bull is an important decision for cow-calf producers. To justify the price paid for a bull, cattlemen may utilize several criteria. They must also determine if the specific selection criteria used add or detract from the value of a particular animal. The study reported here evaluated 13 years of data presented to bull buyers at a graded bull auction in Florida. Results of this study indicated that buyers placed significant emphasis on the following criteria: grade of bull, age, birth weight, sale weight, breed and year of sale. Buyers paid more for a bull evaluated as having superior phenotype and breeding potential. Younger bulls were preferred to older bulls, and bulls with increasing birth weights were discounted. While expected progeny differences (EPD) data are considered a useful selection tool, observations from this study suggest that progeny information had little or no effect on buying decisions, and thus the value of a particular bull. There was, however, a significant effect of breed on sale price: Angus bulls were the preferred breed and sold at a premium compared to other breeds consigned. Year of sale affected the price paid for a bull, with some years more significant than others. In general, producers at this sale did not discount or show prejudice to bulls brought from out-of-state.
Posterior paresis resulting from a vertebral body fracture in a bull
Authors: Foster Derek M. , Smith Geoffrey W. , Pandiri Arun R. , Blond Laurent R.
Published: March 2023

A 2.5-year-old, mixed-breed rodeo bull was examined with a four-month history of ataxia and weakness in the pelvic limbs. The neurologic signs were noted while the bull was on pasture breeding cows. Spinal radiographs revealed a compression fracture of the 13th thoracic vertebrae, and myelography showed impingement of the spinal cord due to the fracture. Necropsy examination confirmed the diagnosis of a compression fracture of T13 with secondary damage to the spinal cord. Vertebral fractures are uncommon in adult cattle, yet this case appears to be unrelated to any previously published causes. Furthermore, myelography can be an effective diagnostic test in the evaluation of spinal cord disease in adult cattle.
Comparison of two Mannheimia haemolytica Immunization Programs in Feedlot Calves at High Risk of Developing Undifferentiated Fever/Bovine Respiratory Disease
Authors: Perrett Tye , Wildman Brian K. , Abutarbush Sameeh M. , Pittman Tom J. , Jones Corey R. , Pollock Colleen M. , Schunicht Oliver C. , Guichon P. Timothy , Jim G. Kee , Booker Calvin W.
Published: March 2023

A field study was conducted to compare the relative effect of a Mannheimia haemolytica toxoid (Presponse® SQ, Wyeth Animal Health, Division of Wyeth Canada, Guelph, Ontario) and a Mannheimia haemolyticaPasteurella multocida bacterin~toxoid (Pulmo-guard™ PHM-1, Boehringer Ingelheim (Canada) Ltd., Burlington, Ontario). Upon arrival at the feedlot, 5,128 animals were enrolled in the study and randomly assigned to two experimental groups. Animals in the first group received Presponse® SQ (PSQ), while animals in the second group received Pulmo-guard™ PHM-1 (PHM-1). Animals in each experimental group were housed in separate pens with 10 pens per experimental group. With respect to morbidity, the first undifferentiated fever relapse, overall chronicity and overall wastage rates were significantly (P<0.05) lower in the PSQ group as compared to the PHM-1 group. There were no significant (P~0.05) differences in any of the other morbidity or mortality outcome variables between the experimental groups. In addition, there were no significant (P~0.05) differences in average daily gain or the dry matter intake-to-gain ratio between groups. The PSQ group had a higher proportion of carcasses grading YG Canada 3 (P<0.05) than the PHM-1 group. In the economic analysis, there was an advantage of $4.06 CDN/animal in the PSQ group. Based on these results, it is more cost-effective to use PSQ than PHM-1 in feedlot calves at high risk of developing bovine respiratory disease in western Canada.
Comparison of pooled testing to individual testing with an ear-notch antigen-capture enzyme-linked immunosorbent assay for bovine viral diarrhea virus.
Authors: Funk Rebecca A. , Thomson Daniel U. , Renter David G. , White Brad J. , Guillossou Stephane
Published: March 2023

Thirty-seven skin samples (ear notches) from individual antigen-capture enzyme-linked immunosorbent assay (ACE)-positive cattle were collected and pooled with negative samples in pools of two, three, four, five, 10 and 15 samples to experimentally determine an optimum pool size for the testing protocol for bovine viral diarrhea virus (BVDV). All positive BVDV pooled samples containing ACE-positive skin specimens resulted in positive tests for all pool sizes investigated. Samples in the 15 ear-notch pools, despite remaining positive, approached the detection limit of the assay. An economic analysis of pooled ACE testing was undertaken to determine the most economically rewarding pool size within the constraints of the test. The analysis demonstrated that as BVD PI prevalence increased, optimal pool size decreased. In all cases, a point of diminishing returns was seen until there was a reversal of the trend, and an increased pool size increased the cost of testing on a per-head basis regardless of BVD PI prevalence. Given the results from the economic analysis and the evaluation of ACE pooled testing, these data suggest that pool sizes of five to 10 samples may be most advantageous both economically and for reliably to detect persistently infected animals.
AABP Conference (2007): Executive Vice-President's Report
Authors: Bovine Practitioners American Association of
Published: March 2023

Description of the 2007 American Association of Bovine Practitioners Conference.
Effects of a Growth-promoting Implant Containing Tylosin Tartrate on Performance, Buller Incidence and Carcass Characteristics of Feedlot Steers
Authors: Bryant T. C. , Rabe F. M. , Bowers D. N. , Hutches D. V. , Jarnagin J. J.
Published: March 2023

A total of 13,732 animals were allotted to 64 pens (average 215 head per pen) in two commercial feedyards to compare the effects of growth-promoting implants with and without tylosin tartrate on performance, carcass merit and buller incidence in yearling steers. Implant formulations used in the study included 120 mg trenbolone acetate and 24 mg estradiol with 29 mg of tylosin tartrate (120/24 T) and 120 mg trenbolone acetate and 24 mg estradiol (120/24). Steers implanted without tylosin tartrate tended to have a lower incidence of bullers (1.17 vs 1.49%; P =0.08), and had a greater percentage of USDA quality grade Prime and Choice carcasses (42.51 vs. 40.26%; P =0.02) than steers given an implant with tylosin tartrate. No other differences in performance or carcass characteristics were noted ( P >0.10). Under the conditions of this study, there was no benefit to using tylosin tartrate in generically comparable growth-promoting implants.
Herd-level Management and Biosecurity Factors associated with Measures of Reproductive Success in California Beef Cow-calf Herds
Authors: Hoar Bruce R. , Bell Tremon C. , Villanueva Veronica , Davy Josh , Forero Larry , Maas John
Published: March 2023

A cross-sectional study was performed to evaluate the relationship between herd-level management and biosecurity practices in a sample of California's beef cow-calf operations, and the estimated within-herd prevalence of antibodies to Neospora caninum , Anaplasma marginale, and the persistent carrier state of bovine viral diarrhea virus (BVDV PI). Serum samples were collected from 917 adult beef cows from 29 herds. Multivariable linear and logistic regression models were created to predict calving season length and the probability of a cow weaning a calf using selected herd-level management and biosecurity factors and the seroprevalence data. The overall seroprevalence of A. marginale , N. caninum and BVDV PI was 47.4% (435/917), 8.9% (82/917) and 0.1% (1/917), respectively. The multiple linear regression analysis revealed no significant associations between management variables and calving season length. A logistic regression model found that the probability that a cow weaned a calf was associated with the number of first-calf heifers in the herd, whether the bulls were semen tested, whether the herd had a history of epizootic bovine abortion, and if the cow herd was vaccinated against Clostridium spp. Based on these findings, we conclude that herd-level management and biosecurity factors may be associated with reproductive success in beef cow-calf farms in California through their effect on the probability that a cow weans a calf.
Occurrence of Mycobacterium avium subspecies paratuberculosis Infection in Cattle in North Dakota,1995-2005.
Authors: Uzoigwe Jacinta C. , Oloya James , Dyer Neil W. , Gibbs Penelope S. , Khaitsa Margaret
Published: March 2023

The objective of this study was to evaluate trends and risk factors for Mycobacterium avium subspecies paratuberculosis (MAP) shedding in cattle in North Dakota. The North Dakota State University Veterinary Diagnostic Laboratory records of fecal culture-positive MAP cases diagnosed from 1995 to 2005 were examined. Epidemiological data on clinical history, age, sex, breed, herd size and county of origin were extracted. Additionally, data on producers enrolled in North Dakota's Voluntary Johne's Disease Control Program were obtained from the North Dakota State Veterinarian's office. Data were analyzed using Geographic Information Systems Arc Info 9.1 software, Epi Info version 6 and SAS version 9.2. Of the 53 counties in North Dakota, 42 (79%) reported MAP infection (range 1-86, median 6) in both beef (n=204) and dairy cattle (n=175). Also, there was a correlation between distribution of cases by county and distribution of producers participating in the ND Johne's Disease Voluntary Control Program; participating counties had more MAP cases reported than counties without participants. The number of MAP cases reported increased during the study period with seasonal trends, as shedding was higher in winter and spring than summer and fall. Chi-square and logistic regression analyses indicated that large herds, female, beef animals and animals greater than four years of age were more likely to be categorized as high shedders of MAP than herds without these attributes.
Clinical observation on differential effects of the trace elements selenium and copper during bovine embryo transfer
Authors: Scherzer Jakob , Sebastian Manu , Davis Catherine , Ensley Douglas C. , Hurley David J.
Published: March 2023

This field study was undertaken because previous studies indicated that deficiencies in selenium (Se) and/or copper (Cu) could negatively affect reproductive performance in cattle. Blood (EDTA) and serum were collected from 43 cows four weeks after embryo transfer at the time of pregnancy examination, and Se and Cu levels were measured. Mean blood Se and serum Cu levels were 0.1±0.07 ppm and 0.66±0.12 æg/ml, respectively. Observed rate of successful pregnancy in recipient cows (termed pregnancy rate in this paper) was decreased with low or marginal blood Se concentrations (P=0.02), but serum Cu concentrations had no influence on pregnancy rate. While embryos of quality 1 or 2 had an equivalent pregnancy rate and the two sires used had no effect on pregnancy rate, a significant effect of donor cow on the pregnancy rate in recipients was observed (P=0.03). If the donor effect was included in the analysis, recipient cows with low or marginal blood Se concentration tended to have reduced embryo transfer efficacy (P=0.08).
Case report
Authors: Rollin Emmanuel , Nickerson Stephen C. , Ensley Doug , Berghaus Roy D.
Published: March 2023

This case study describes an outbreak of mastitis in beef bulls in Georgia in the summer of 2007, and the observed effects of mastitis on measures of growth. Twenty-one of 97 bulls at a bull test station were found to have enlarged mammary glands with expressible fluid and purulent material. Bacteriologic culture of the exudates revealed numerous environmental pathogens. Treatment was attempted with intramammary infusion of chlorhexidine diacetate and intramammary antimicrobials, but did not result in clinical cure. Affected and unaffected bulls did not differ in average daily gain or weight per day of age. Reproductive consequences of mastitis could not be evaluated.
Case Study
Authors: Dubuc Jocelyn , Kitts Bianca , LeBlanc Stephen J. , Or-Rashid Mamun , AlZahal Ousama , McBride Brian W.
Published: March 2023

A 100-cow dairy herd was investigated for chronic milk fat depression. Implementation of traditional measures to reduce the impact of altered rumen fermentation by increasing physically effective fiber intake only partially alleviated the problem. A field study was then performed to quantify the effect of reducing polyunsaturated fatty acid intake on milk fat and milk fatty acid profile. A total of 22 cows randomly selected in the herd were enrolled in the study. Dietary intake of linoleic acid was decreased from 0.609 lb (277 g) to 0.519 lb (236 g) per cow per day by modifying the ration. The effect of ration reformulation was analyzed in linear regression models using repeated measures within cows. Milk production, milk composition, and milk fatty acid profile data were considered the outcomes. Ration reformulation was associated with an increase of 0.3 percentage points of milk fat (P<0.01) and a concomitant decrease of trans-10, cis-12 conjugated linoleic acid in milk (P<0.001). Results from this case study indicate a small reduction of polyunsaturated fatty acid intake may mitigate milk fat depression in dairy cows.
Beef Heifer and Cow Estrous Synchronization Programs
Authors: Lamb G. C.
Published: March 2023

Recent estrous synchronization research has aimed to develop reliable protocols that: 1) rely solely on fixed-timed artificial insemination (TAI); 2) require a maximum of three animal handlings; and 3) are successful in estrous-cycling and non-cycling females. In cows, insertion of an intravaginal progesterone insert during the seven-day interval between the initial gonadotropin- releasing hormone (GnRH) and prostaglandin injections of the CO-Synch protocol enhanced pregnancy rates by 9 to 10%. Recent research has shown that TAI protocols yield pregnancy rates similar to a protocol involving detection of estrus plus a fixed-time cleanup AI for females not detected in estrus. Initiation of estrous cycles in· non-cycling cows is likely the primary manner in which beef producers may improve fertility in response to estrus synchronization and TAI protocols. Treatment of non-cycling females with progesterone and GnRH increases the percentage of cycling females and improves fertility to a TAI, but inducing cyclicity with human chorionic gonadotropin (hCG) fails to enhance fertility in TAI protocols. Supplementing progesterone after TAI fails to increase pregnancy rates in beef cattle. In contrast, administration ofhCG seven days after TAI induced an accessory corpus luteum, increased progesterone, and tended to enhance pregnancy rates. Use of TAI protocols reduces the hassle factors associated with ovulation synchronization and AI, and provides cattle producers efficient and effective tools for capturing selective genetic traits of economic consequences. Location variables, however, such as differences in pasture and diet, breed composition, body condition, postpartum interval, climate, and geographic location, affect the success of TAI protocols.
Effects of Removing Cows from Chronic Oxytocin use During Lactation
Authors: Leone W. M. , Nydam D. V. , Welcome F. , Warnick L. D.
Published: March 2023

The objectives of this study were to investigate the effect of discontinuation of chronic oxytocin supplementation on lactating dairy cows and to determine if there was a difference between methods of discontinuation. The study was conducted on a commercial dairy in central New York milking over 1,200 cows, with more than 80 cows being supplemented with oxytocin prior to the start of the study. Seventy-seven cows receiving supplemental oxytocin were enrolled in the study and randomly assigned to one of four treatment groups: 1) abrupt discontinuation; 2) abrupt discontinuation with a needle stick at the normal time of oxytocin injection; 3) graduated decrease in oxytocin dose; and 4) a control group that was only monitored. Total milk weight, milk in the first two minutes, total milking time, and bimodality of milk flow were measured at every milking for 12 milkings before and after the initiation of the treatment protocol. Non-parametric paired analysis was used within treatment group before and after initiation of treatment, and non-paired analysis was used to analyze differences between treatment groups. Other than the control group, all experimental groups showed a significant decrease in milk production per milking (P<0.005), ranging from 2.8-7.4 lb (1.3-3.4 kg) per milking per cow. None of the cows ceased lactating. There were no significant differences in milk produced in the first two minutes, total milking time, or the number of bimodal milk flows in any of the groups (P>0.09). No significant differences (P>0.11) in the change in milk production per milking or milk produced in the first two minutes were found between the group that underwent graduated discontinuation of oxytocin and the group abruptly removed from oxytocin supplementation without sham injection. These results show that dairy producers can stop supplementing cows with exogenous oxytocin in the parlor by either abrupt discontinuation or a weaning protocol with a loss of milk similar to that gained from oxytocin supplementation, and cows will not cease to lactate.
Bovine viral diarrhea virus (BVDV) status in cow-calf herds and associations with biosecurity and production practices among Montana beef producers
Authors: Nickell Jason S. , White Brad J. , Larson Robert L. , Renter David G. , Sanderson Mike W. , Peck Clint
Published: March 2023

Bovine viral diarrhea virus (BVDV) manifests in several clinical syndromes. Cattle persistently infected (PI) with BVDV are lifelong shedders and the primary reservoir of the virus in the herd. The Montana BVD-PI Herd Biosecurity Program assists Montana beef producers with BVDV education, detection, and prevention. A survey was conducted to determine associations among specific biosecurity and management practices and herd BVDV status. Of the 585 beef herds enrolled in the program from 2006-2009, 6.5% (n=38) detected greater than or equal to 1 PI animal. Among these positive herds, the within-herd PI prevalence ranged from 0.12% to 20.0%. Among the respondent herds with known BVDV status (n=230), 4.3% (n=10) were previously diagnosed with greater than or equal to 1 PI animal. Herds that annually vaccinated home-grown heifers and bulls prior to introduction to the resident herd displayed a significantly reduced risk of being BVDV positive (P less than 0.10). Producers with high self-perceived BVDV knowledge were more likely (P less than 0.10) to annually vaccinate the resident herd for BVDV, less likely (P less than 0.10) to participate in communal grazing practices from breeding to weaning, but more likely (P less than 0.10) to transport pregnant heifers off-site with subsequent reintroduction to the resident herd. These data suggest that although beef producers in Montana engage in management practices potentially increasing the risk of BVDV introduction, educated producers have taken steps to mitigate that risk.
Efficacy of a non-adjuvanted, modified-live virus vaccine in calves with maternal antibodies against a virulent bovine viral diarrhea virus type 2a challenge seven months following vaccination
Authors: Stevens Elliot T. , Brown Michael S. , Burdett William W. , Bolton Michael W. , Nordstrom Scott T. , Chase Christopher C. L.
Published: March 2023

In the presence of maternal antibodies, 26 calves three days of age were either vaccinated (n=15) with a single dose of a non-adjuvanted, pentavalent, modified-live vaccine containing bovine herpes virus-1, bovine respiratory syncytial virus, bovine viral diarrhea virus 1a (BVDV1a), bovine viral diarrhea virus 2a (BVDV2a), and bovine parainfluenza-3, or sham vaccinated with sterile saline (n=11). At approximately seven months post-vaccination, when vaccinates and non-vaccinates were seronegative to BVDV1a and BVDV2a antibodies, all calves were intranasally challenged with a virulent BVDV2a (strain 1373). Clinical signs of BVDV infection were monitored beginning three days prior to challenge and concluded on day 21 after challenge. Calves vaccinated in the face of maternal antibodies (IFOMA) were less impacted by the challenge. Based on clinical parameters, vaccinates had reduced clinical scores, rectal temperature, weight loss, and mortality compared to sham-vaccinated animals. Vaccinated animals had higher levels of circulating white blood cells and fewer animals were viremic than sham-vaccinated animals. This study demonstrated that a calf as young as three days of age when vaccinated IFOMA can be protected against a virulent BVDV2a challenge with a non-adjuvanted, pentavalent vaccine.
Relationship between milking fraction and immunoglobulin g concentration in first milking colostrum from holstein cows
Authors: Godden Sandra M. , Hazel Amber
Published: March 2023

The objective of this study was to describe immunoglobulin G (IgG) concentrations in various milking fractions (0% fraction [cisternal], 25% fraction, 50% fraction, 75% fraction, 100% fraction [alveolar], or composite sample) in first milking colostrum from Holstein dairy cows. First milking colostrum was collected from 26 primiparous and multiparous Holstein cows on a commercial dairy farm in western Wisconsin. For each cow, 10-mL colostrum samples were collected representing the following milking fractions: cisternal colostrum (first 10-15 seconds), 25%, 50%, 75%, 100% (alveolar), and a composite sample (entire milking), and tested for IgG concentration (mg/mL). Contrast analysis showed that IgG concentrations were significantly higher in cisternal colostrum samples as compared to IgG concentrations in the 25% fraction, the 50% fraction, the 75% fraction, and the composite sample. Levels of IgG in cisternal samples were not different than levels in the 100% (alveolar) fractions. Apart from the cisternal samples, IgG concentrations were not different among the other milking fractions tested. Producers or researchers wishing to measure colostrum quality should avoid using forestripping samples for testing purposes, as these samples may overpredict the IgG concentration in what will be fed to the calf. The current study found no difference in IgG concentration among the other milking fractions. However, when considering the effect of milking fraction on other milk components that may be of importance to the neonatal calf, including fat, producers should completely milk out the cow at the time of first colostrum harvest.