bluuebunny/crossref_metadata_2025 huggingface dataset:
Unusual multiple abnormalities in a bovine reproductive tract
Authors: Hailat Nabil , Fathalla Mahmound , Lafi Shawkat , Al-Rawashdeh Odeh
Published: March 2023

Not all genital disease in cattle, whether congenital or acquired, can be diagnosed by the usual clinical methods. Studies on slaughterhouse materials can be very useful in detecting certain diseases that may be missed by the practicing veterinarian. The examination of 228 bovine reproductive tracts at the slaughterhouse revealed 7 .8% were abnormal on gross examination. In another study of 500 specimens to determine the incidence of ovarian diseases, 2.8% and 1 % of the reproductive tracts exhibited ovarian cysts and paraovarian cysts, respectively. Congenital abnormalities such as Bartholin gland cyst in a cow have also been associated with ovarian cysts of cows. In our two previous surveys, we have not observed multiple abnormalities in the reproductive tracts of cows.

The objective of this report is to provide macroscopic description of a Gartner's duct cyst, ovarian cyst, paraovarian cyst and a parametrial abscess as well as hemorrhagic cystitis in the reproductive tract of a cow slaughtered at Irbid slaughterhouse. The macroscopic appearance and histopathologic lesion of a perimetrial mass are also described.
Twenty-Ninth Annual Conference of the American Association of Bovine Practitioners
Authors: American Association of Bovine Practitioners
Published: March 2023

Description of the the Annual Conference of the American Association of Bovine Practitioners (29th : 1996), officers, district news, events, awards, and other news.
Prions
Authors: Hartigan Pat
Published: March 2023

In the midst of the current BSE scare veterinarians are being called on for their opinion. In order to give it, members of the profession must first understand the etiology of BSE and the possibility of its transmission to other species.
Incidence of Joint Infection in Calves
Authors: Kallo O. J. , Abdul-Ghani Z. G. , Khalid F. R.
Published: March 2023

Clinical examination of 34 naturally affected calves with septic arthritis were done in the Baghdad area. Bacteriological examination of the synovial fluid taken from the affected joints showed that 21 cases were positive (61.8%) and 13 were idiopathic (38.2%). The incidence was higher in males (64.7%) than in females (35.2%) in the first month of age and infection of the carpal joints were more common than those of the hock joints. The highest incidence (11.8%) of positively affected joints were due to mixed infection caused by Klebsiella ozaenae & Proteus mirabilis.
OVSYNCH
Authors: Seguin Brad
Published: March 2023

Ovsynch has been widely reported in the lay press and has understandably created considerable interest among dairy producers seeking better herd reproductive performance and/or elimination of heat detection. This program may produce acceptable results but, in my opinion, it is still too early to predict what results will be on your clients' farms. While many recent estrus control programs and heat detection aids are most helpful in freestall and loose housing arrangements, Ovsynch offers relief from the pressure to do lx or 2x daily turn-out of cows for heat detection in herds housed in stanchion barns. Methods of estrus control (other than Ovsynch) using only PGF have produced similar results in dairy herd reproductive management trials but contemporary experimental comparisons are not yet available.
Repeated oestrus synchrony and fixed time AI in beef cows at pasture
Authors: Penney C. D. , Lowman B. G. , Scott N. A. , Scott P. R.
Published: March 2023

The feasibility of breeding spring calving, single-suckled beef cows without the use of natural service was explored over two breeding seasons using repeated oestrus synchrony and fixed-time AI. Initially, cows were oestrus synchronised using subcutaneous norgestomet implants inserted for ten days with prostaglandin injection prior to implant removal. Cows were inseminated once, 56 hours after implant removal and 12 days later all cows were re-treated with norgestomet implants to allow a second synchronised service. Twenty-one days after the first synchronised AI, milk samples were drawn for progesterone assay and the norgestomet implants removed. Cows received a second service 56 hours later if the 21 day milk progesterone assay suggested they were not pregnant. All cows receiving a second service were re-treated with norgestomet implants as before to allow a third synchronised service as necessary. Pregnancy was later confirmed by manual rectal palpation. In year one, 48 cows entered the program and the pregnancy rates to the first, second and third synchronised services were 56%, 69% and 40% respectively with 17% of cows barren at the end of the breeding period. In year two, 69 cows entered the program and the pregnancy rates were 58%, 48% and 33% to each service with 20% of cows barren at the end of the breeding period. The accuracy of milk progesterone assay for pregnancy diagnosis was 84% and 87% in years 1 and 2 respectively. The study showed it is possible to achieve a calving rate of at least 80% following a 46 day breeding period using a combination of oestrus synchrony and fixed-time AI in beef cows at pasture.
Productivity, management and disease in dairy cattle
Authors: Logue D. N.
Published: March 2023

There is a widely held view that increased productivity and intensification of dairy cow management is necessarily associated with reduced welfare and conversely extensive systems are good. This is a gross over simplification and in some cases plainly wrong. However the main problem besetting the industry is that we still have no reliable measure of how well the cow is coping with the stresses imposed by this search for greater efficiency. The three main reasons for involuntary culling are infertility, mastitis (including SCC) and lameness. Together with weight and condition score and some simple behavioral parameters these offer a practical yardstick to measure herd welfare. However we still need to develop our understanding of the fundamental etiology of these conditions and the cost benefits of any management intervention since we may well need to weigh them differently under different circumstances.
Topographic distribution pattern of vacuolation in the central nervous system of cattle infected orally with bovine spongiform encephalopathy
Authors: Hawkins S. A. C. , Wells G. A. H. , Simmons M. M. , Blamire I. W. H. , Meek S. C. , Harris P.
Published: March 2023

Bovine spongiform encephalopathy (BSE) is a scrapie-like disease of cattle first recognized in the United Kingdom in 1986. The predominant pathology is a vacuolar degeneration of the central nervous system. In naturally affected cattle the severity and distribution of these vacuolar changes present an almost invariable pattern. The source of infection responsible for the current epidemic is considered to be commercially processed feed contaminated with a scrapie-like pathogen. A foodborne source of infection is also considered the likely origin of scrapie-like disease in other mammalian species, including the domestic cat and several species of exotic bovids and felids in zoological collections, which have occurred contemporaneously with the BSE epidemic. In common with other scrapie-like diseases BSE has been transmitted experimentally to several other species. The transmission of BSE to cattle by the oral dosing of calves with BSE-affected brain stem homogenate has been reported previously. Histopathological examinations of the brain based on the lesion profile system, developed originally for the characterization of scrapie in laboratory mice, were used to examine the distribution and severity of vacuolar changes in these cattle. The results were compared with the vacuolar profile in naturally affected cattle. The distribution of vacuolar changes in cattle dosed orally with BSE closely resembles that observed in naturally affected cattle providing experimental evidence that this route closely simulates natural infection and subsequent neural pathogenesis.
Overview of BSE in the United Kingdom: U.S. Response
Authors: Detwiler Linda A.
Published: March 2023

Below, by the following five topics, are some questions and answers related to this situation:Topics:1. Bovine spongiform encephalopathy (BSE)2. Other human and animal transmissible spongiform encephalopathies (TSEs)3. Creutzfeldt-Jakob disease (CJD) and variant-CJD (V-CJD)4. USDA actionsa. Surveillanceb. Educationc. Preventiond. Risk Assessment5. Feeding of ruminant protein to ruminants
Prevention of bloat in pastured cattle
Authors: Lowe L. B.
Published: March 2023

Bloat in cattle grazing legume pastures can depress production and cause death. Development of controlled release capsules (CRC) containing monensin for prevention of bloat is described. Early studies were based on CRC devices delivered 170 mg monensin/day in beef cattle. Significant live weight gains and reduction in both bloat and death were found. In dairy cows, devices which delivered 300 mg monensin/day reduced bloat and increased milk and protein yields. Inclusion of silicone glycol in the monensin CRC showed some benefits both in vitro and in vivo although a study on highly bloat susceptible dairy cows failed to show a difference.
Transgenics and dairy animal reproduction
Authors: Keefer Carol L.
Published: March 2023

Application of transgenic technology to domestic animals has been limited in the past. Improvements in reproductive techniques, including in vitro embryo production, and economic incentives have lead to the implementation of transgenic programs by commercial groups. Transgenic technology incorporates molecular and reproductive techniques in order to direct and harness the tremendous protein synthetic capacity of the mammary gland of dairy animals. Transgenic animals (animals which have exogenous DNA stably integrated into their genome) can be used to express value-added exogenous proteins in their milk for subsequent purification or to increase milk protein and calcium concentration in their milk for increased efficiency of production of processed dairy foods.
Environmental quality in dairy housing
Authors: Janni Kevin A.
Published: March 2023

The purpose of this presentation is to propose that dairy producers begin monitoring select environmental characteristics in their dairy housing facilities to provide quantitative information about the performance of their facilities and its impact on the well-being of their dairy animals. Good management requires accurateperformance data to compare against performance standards to identify problem areas or areas for improvement. For good dairy producers to continue too improve upon their existing performance they need to establish environmental performance standards, begin monitoring, evaluate performance, and implement appropriate management changes when performance is not acceptable.
Observations on claw abnormalities in beef cows
Authors: Greenough Paul R. , Petrie Lyall , Campbell John , Scott Todd
Published: March 2023

In June 1994, a study began on a herd of cattle in Canada. The herd was visited 5 times. A second herd was examined in October 1994, and visited in spring and autumn until October 1997. A further 10 herds were examined at least once in a supplementary study. Front feet of all cows and hind feet of most were examined and a detailed record of lesions observed was made. Sandcracks were classified into 5 categories (types 1 to 5), depending on the location of the lesion. The degree of severity of the sandcrack was defined by its width (2 to 10 mm). Several possible causes were identified, including increased body weight, the presence of horizontal defects and bending of the dorsal surface of the claw. Not all cracks originated from cracks at the coronary band (type 1). In 2 groups of heifers it was found that the rate of claw growth was approximately 0.46 cm/month during the summer and 0.32 cm/month during the winter. Applying these growth rates to the position of a horizontal defect relative to the skin/horn junction permitted the date on which the defect was formed to be estimated. The incidence of horizontal defects was exceptionally high in some herds of beef cows and was found to vary from 29 to 100% of the cows in 6 of the herds in the study.
Segregation or use of separate milking units for cows infected with Staphylococcus aureus reduced prevalence of infection and bulk tank somatic cell counts
Authors: Wilson David J. , Gonzalez Ruben N. , Sears Philip M.
Published: March 2023

Dairy herds (n = 76) with initial prevalence of Staphylococcus aureus IMI> 10% were included in this study, from among approximately 2800 herds visited between January 1992 and July 1994 by the Quality Milk Promotion Services at Cornell University. The farms were located in New York and Pennsylvania. Other inclusion criteria were that herds did not change teat dipping or dry cow treatment practices, were not segregating cows that were positive for S. aureus at the initial visit, and did not cull > 50% of those found positive on the initial visit. Paired t tests and Wilcoxon rank sum tests were methods of statistical analysis. Mean herd size was 59 lactating cows, and herd size ranged from 28 to 436 cows. Percentage of herds teat dipping, using dry cow treatment, and mean herd size were not different among segregation groups. Mean number of visits (3.5 per herd) did not differ among groups. During a follow-up period (6-to-24 mo), segregation or separate milking of cows (n=21 herds) that were positive for S. aureus resulted in reduction of prevalence from 29.5 to 16.3%, and bulk tank SCC from 600,000 to 345,000/ml. Prevalence of S. aureus mastitis was unchanged for herds (n=55 herds) not segregating S. aureus cows, 22.5 to 20.2%, and the change in SCC from 698,000 to 484,000 for nonsegregated herds was less of a reduction than for the segregating herds. Segregation or use of separate units for cows known to be positive for S. aureus is an effective mastitis control practice.
Ultrasonographic investigations of bovine cardiac lesions
Authors: Boyd J. , Spence S. , Paterson C. , Fitzpatrick J. , Thompson H.
Published: March 2023

In this paper the role of B mode real time diagnostic ultrasonography, both with and without Doppler and colour flow mapping facilities, in the investigation of bovine cardiac disease is discussed. Its uses are illustrated in a number (n = 18) of clinical cases. The examination technique is explained along with the equipment and the success of the simplistic approach of B mode echocardiography, which is compared with the application of Doppler vascular flow analysis and colour flow mapping. Conditions such as pericarditis, endocarditis and some congenital defects can be interrogated satisfactorily with B mode but smaller valvular lesions and complex congenital anomalies require Doppler techniques. In the future, the use of echocontrast agents may permit the investigation of these latter problems with simple equipment in the in vivo application of such a contrast agent is illustrated.
Digital dermatitis
Authors: Leist G. , Rudolph R. , Natterman H.
Published: March 2023

Tissue samples of skin affected by digital dermatitis were studied histopathologically together with post-mortem findings and anamnestic datas to achieve better understanding of this disease. There are hyperplastic, ulcerative, proliferative and combined forms distinguishable. The epidermal cells show signs of degeneration, hypertrophy and hyperplasia, combined with differing extensions of cell destruction by bacteria and spirochetes. Dermal reactions contain arteriosclerosis-like plaques, activation of endothelial cells, thrombosis and different patterns of perivascular infiltration. It is concluded that epidermal lesions are a sequel of dermal malperfusion. Partial or total ischaemia leads to hyperplasia and ulceration, respectively. Endotoxins of gram negative bacteria taking part in other diseases in the same cattle are strongly presumed as causing agents. This indicates a multifactorial pathogenesis.
Clinical immune response to experimental BHV-1 challenge of cattle treated with florfenicol at the time of BHV-1 vaccination
Authors: Hunsaker Breck D. , Perino Louis J. , Lechtenberg Kelly F. , Reddy Jeeri
Published: March 2023

The clinical immune response of cattle experimentally challenged with bovine herpesvirus 1 (BHV-1) after treatment with florfenicol at the time of BHV-1 vaccination, was measured in groups of 10 unvaccinated beef-type, crossbred steers randomly assigned to one of 4 treatment groups: (a) florfenicol-treated and BHV-1-vaccinated (FF+, VX+), (b) florfenicol-untreated and BHV-1 vaccinated (FF-, VX+), (c) florfenicol-treated and BHV-1 unvaccinated (FF+, VX-), and (d) florfenicol-untreated and BHV-1 unvaccinated (FF-, VX-). Recommended doses of florfenicol were given on days 24 and 22 before challenge. BHV-1 vaccine was administered both intranasally and i.m. on day 22 before challenge to cattle in both vaccinated groups. BHV-1 experimental challenge was done 21 days after vaccination (day 0). Post-challenge rectal temperature was significantly lower in vaccinated groups (FF+, VX+ and FF-, VX+) as compared to unvaccinated groups (FF+, VX- and FF-, VX-). Post-challenge cumulative clinical score composed of cough, nasal and ocular discharge, and respiration character, was significantly lower in vaccinated groups (FF+, VX+ and FF-, VX+), as compared to unvaccinated groups (FF+, VX- and FF-, VX-). Post-challenge BHV-1 shedding was significantly reduced in vaccinated groups (FF+, VX+ and FF-, VX+) as compared to unvaccinated groups (FF+, VX- and FF-, VX-). Rectal temperature and clinical illness scores following vaccination and challenge were not different between florfenicol-treated (FF+, VX+ and FF+, VX-) and non-treated cattle (FF-, VX+ and FF-, VX-). Serum neutralization titres were significantly greater in florfenicol-treated groups (FF+, VX+ and FF+, VX-) as compared to untreated groups (FF-, VX+ and FF-, VX-) 21 days after vaccination (day 0). Leukograms were within normal limits for all treatment groups at all time points. Vaccinated calves (FF+, VX+ and FF-, VX+) lost 7.95 lb/head, while unvaccinated calves (FF+, VX-, and FF-, VX-) gained 3.15 lbs/head day -24 to day -20. It is concluded that BHV-1 vaccinated calves developed clinically protective immune responses. There was no indication of interference by florfenicol with response to vaccination.
Comparison of three α2-antagonists, yohimbine, tolazoline, or atipamezole for reversing the anesthetic effects of medetomidine and ketamine in dairy calves
Authors: Lin Hui-Chu , Riddell M. Gatz , DeGraves Fred J.
Published: March 2023

Yohimbine (0.25 mg/kg i.v.), tolazoline (2.2 μg/kg i.v.) or atipamezole (60 μg/kg i.v.) were given to 6 healthy, Holstein calves (156.8-241.1 kg) 30 min after anaesthesia with a combination (MK) of medetomidine (20 μg/kg i.v.) and ketamine (2.2 mg/kg i.v.) with an interval of 1 week between treatments. Heart and respiratory rates, indirect arterial blood pressures (systolic (SAP), mean (MAP), diastolic (DAP)), and arterial blood gases were measured. Calves became sternally recumbent in 2±14 s for a duration of 94±25 min after administration of MK. Respiratory rate, PaCO2 and arterial blood pressure were significantly increased while PaO2, pHa and SaO2 were significantly decreased during anaesthesia. The values for most of the blood gas variables returned to normal after administration of tolazoline and atipamezole. The duration of recumbency following administration of yohimbine, tolazoline, or atipamezole was 80±22, 46±9 and 34±3 min, respectively. Calves stood in 48±20, 16±9 and 4±3 min, respectively, after the injection of yohimbine, tolazoline and atipamezole. It was concluded that medetomidine and ketamine combination can be used effectively to induce anaesthesia in dairy calves. Either tolazoline or atipamezole can be administered to antagonize the anaesthetic effects and induce rapid recovery.
Association between selected metabolic parameters and left displaced abomasum in dairy cows
Authors: Geishauser T. , Leslie K. , Duffield T. , Edge V.
Published: March 2023

The association between selected metabolic parameters and subsequent left displaced abomasum (LDA) diagnosis in dairy cows was investigated in 44 LDA cows sampled in the third week before calving (a.p.), which was at a median of 34 days before LDA diagnosis; 36 LDA cows were sampled in the first week after calving (p.p.), which was at a median of 14 days before; and 28 LDA cows were sampled in the second week p.p., which was at a median of 9 days before LDA diagnosis were used. Each case was matched to 3 controls by herd and calving date. Data were available from a large field study. Aspartate aminotransferase (AST) activity, the concentrations of beta-hydroxybutyrate (BHB), glucose, calcium and urea in blood, and the body condition score (BCS) were monitored. Logistic regression was used to analyse the association between these parameters and subsequent LDA, adjusting for the effects of parity and pretreatment. A separate model was used for each sampling week and each parameter. In the third week a.p., none of the parameters were significantly associated with LDA. AST and BHB sampled in the first week p.p. and in the second week p.p. were significantly associated with LDA diagnosis. The higher the AST and BHB the higher the odds of being diagnosed subsequently with LDA. The lower glucose and Ca in the second week p.p. the higher the odds of subsequent LDA diagnosis. Urea and BCS were not significantly associated with LDA in any of the weeks examined. It is concluded that AST and BHB in the first and second week p.p. might be used as tests for developing LDA.
Preliminary classification of the bovine respiratory complex into different levels of severity
Authors: Coghe J. , Uystepruyst Ch. , Bureau F. , Van de Weerdt M. L. , Lekeux P.
Published: March 2023

Despite prophylactic measures, mainly including vaccination programs and management measures, respiratory disease remains the major cause of economic losses in the bovine species. Choice of treatment is currently mainly based on the clinicians? personal experience. A theoretical method has been proposed earlier to classify this syndrome into four grades of severity: Grade 1, subclinical disease (no treatment); Grade 2, compensated clinical disease (antibiotics only); Grade 3, noncompensated clinical disease (antibiotics + antiinflammatory drugs); and Grade 4, irreversible clinical disease (no treatment). In order to realize this theoretical classification under field conditions, three techniques, each one evaluating the oxygen transport chain at a different level, have been studied and validated, i.e. pulse oximetry, lactate dosage and the lobeline test. Afterwards, measurements were performed on calves suffering from acute respiratory disease and a preliminary classification was established. This novel approach could orientate and economize therapeutic strategies in bovine respiratory disease.
Effects of an oral antibiotic on fertility in range beef cattle
Authors: Saltman R. L. , Chenoweth P. J. , Rae D. O. , Genho P. C. , Moore S. A. , Crosby G.
Published: March 2023

In a series of trials in Florida, crossbred beef females were fed different chlortetracycline (CTC) regimes relative to weaning and breeding to determine effects on fertility. In trial 1, alternately sorted crossbred yearling heifers were either given CTC at 1.1 mg/kg/day for 30 days before natural breeding (T, n=225) or no CTC (C, n=225). More pregnancies occurred in the treated group compared with controls (71.5% and 56.8% respectively). In experiment 2, crossbred yearling heifers were placed in 3 comparable groups after 3 months postweaning CTC at 1.1 mg/kg/day; A (n=106) controls, B (n=97) CTC at 22 mg/kg/day for 5 days prebreeding, then 1.1 mg/kg/day for the first 30 days of breeding, C (n=101) CTC at 1.1 mg/kg/day for the first 30 days of breeding. Groups did not differ in numbers of pregnancies (overall 71.6%) although days pregnant tended (P<0.10) to favour both CTC groups. In experiment 3, crossbred beef cows were placed in 2 comparable groups (n=149-214) at each of 3 locations; CTC at 1.1 mg/kg/day for 30 days at the start of breeding, and no CTC. Treated females achieved more pregnancies than non-treated (83.3% and 78.4% respectively) and achieved them earlier in the breeding season. In all trials, body condition score (BCS) at breeding was a significant factor in pregnancy outcome. Overall, feeding of CTC to both heifers and cows at the start of breeding appeared to benefit fertility parameters. Both BCS and prior feeding of CTC influenced results.
Effects of teat dilators and teat cannulas on udder health
Authors: Querengasser Klaus , Geishauser Thomas , Hoptner Christoph , Medl Max , Tradati Franco
Published: March 2023

Over a period of 15 days, the teats of 4 dairy cows were inserted with teat dilators, teat cannulae or were left untreated (controls). Cows were milked twice daily. Teat dilators were removed for milking. During milking time, the plugs of the teat cannulae were removed and milk was drained. All teats were examined using endoscopy before the start (day 0) and after the end (day 16) of this study. The California Mastitis Test (CMT) and bacteriological examination were performed on milk collected in the morning on days 0, 5, 11, and 16. The use of teat dilators and teat cannulae was associated with injuries and cisternitis. The character of these injuries indicated that teat dilators and teat cannulae pierce the teat cistern lining. In three of seven teats the removal of the teat cannula caused circular separation and eversion of the Frstenberg rosette and teat canal skin. The use of teat dilators and teat cannulae significantly increased CMT scores and the odds of a positive bacterial culture. It is concluded that the use of teat dilators and teat cannulae may harm udder health.
Cost of respiratory diseases in dairy heifer calves
Authors: Esslemont R. J. , Kossaibati M. A.
Published: March 2023

This paper estimates the total cost of respiratory disease in dairy heifer calves. In a typical dairy herd, 14% of dairy replacement heifer born alive are culled before first calving. Respiratory disease is involved, either directly (death) or indirectly (poor growth rate). Overall cost is a combination of many factors such as, but not limited to, veterinary treatments, loss of performances, extended rearing period, death, delay at first service and capital wasted. Young calves (3-16 weeks) are at higher risk, and mean duration of disease outbreak is 5 weeks. Morbidity and mortality are influenced by the severity of infections.
Milk Yield and Disease
Authors: Gröhn Y. T.
Published: March 2023

The purpose of our research is to develop a comprehensive economic model to assist dairy producers when making treatment and culling decisions. To make profitable decisions, the producer must account for factors including age, production level, stage of lactation, pregnancy status, and disease history. Establishing the interrelationships among disease, milk yield, reproduction, and herd management is necessary for developing a decision model for disease treatment, insemination, and replacement. The objective of our research presented in this paper was to study the relationship between disease and milk production. First, we studied whether high milk yield predisposes a cow to certain diseases and reproductive disturbances. Second, we studied whether certain diseases cause milk loss and increased culling. Third, we are combining all information to develop a comprehensive economic model which will attempt to assess both the beneficial and deleterious effects of increasing milk yield. The data for this study incorporate health, production, and management components for Holsteins in the Northeastern USA and Ayrshires from Finland. The data were analyzed using the Cornell Theory Center Supercomputer. The effect of milk yield was modeled with logistic regression, and conception and culling with a survival analysis technique. The effect of disease on milk yield was analyzed with mixed model analysis. High milk yield predisposed a cow to certain diseases (particularly mastitis). Many diseases led to decreased production. Both milk yield and disease affected reproductive performance and culling. As expected, high milk yield protected against culling, and non-pregnant and sick cows were more likely to be culled. We now are positioned to develop a simple, accurate, and complete framework for a dairy farmer to determine whether a cow should be kept or replaced by a more profitable heifer using all of the biological variables that impact profit-ability in an objective manner.
Pasture deworming and (or) subsequent feedlot deworming with fenbendazole. I, Effects on grazing performance, feedlot performance and carcass traits of yearling steers
Authors: Smith Robert A. , Rogers Karen C. , Huse Scott , Wray Mary I. , Brandt Robert T. , Hutcheson John P. , Nichols Wade T. , Taylor R. Flint , Rains Jerry R. , McCauley Charles T.
Published: March 2023

734 steers, weighing 286 kg, were used during a 118-day grazing period, after which 640 were placed in a feedlot for finishing (average of 121 days, range of 111 to 133 days) to measure the main effects and interactions of 2 pasture deworming treatments (negative control, strategically dewormed with fenbendazole) and 2 feedlot deworming treatments (negative control, dewormed with fenbendazole) on grazing performance, feedlot performance, carcass traits and production economics for yearling steers. Strategic deworming with fenbendazole (FBZ) during the grazing phase increased pasture gain by 22 kg compared with control steers. Feedlot deworming improved performance of steers in all treatments, but it had a much greater effect on performance of pasture control steers. Deworming with FBZ in the feedlot improved daily gain of pasture control steers by 13.4% compared with a 4.2% improvement for steers that had been strategically dewormed on pasture. Similarly, feedlot deworming improved feed/gain ratio by 4.65% for pasture control steers compared with 0.4% improvement for steers that had been strategically dewormed. On a carcass-adjusted basis, feedlot deworming of strategically dewormed steers increased daily gain 6.8%, and feed/gain by 2.9%. Feedlot deworming of pasture control steers increased daily dry matter intake (DDMI) by 7.8% compared with no feedlot deworming, while feedlot deworming increased DDMI by 3.2% in the same comparison for strategically dewormed steers. Carcass traits were affected similarly. Dressing percentage was increased by both strategic deworming on pasture and feedlot deworming with fenbendazole. Feedlot deworming of pasture control steers increased carcass weight by 22 kg, while feedlot deworming of steers that were strategically dewormed on pasture increased carcass weight by 9.5 kg. The percentage of choice carcasses was lower, and the percentage of select carcasses was higher for the pasture control-feedlot control steers compared with the other treatment groups. Strategic deworming during grazing resulted in a net benefit of $33.75 per head. For the complete grazing-finishing system, feedlot deworming of previously non-dewormed steers with FBZ produced a net benefit of $30.61 per head on a carcass-adjusted basis, while feedlot deworming of strategically dewormed steers produced a net benefit of $11.07. Strategic deworming of grazing steers on pasture and yearling steers that were entering the feedlot from summer pasture with FBZ produced clear performance and economic benefits.
Evaluation of the early conception factor dip stick test in dairy cows between days 11 and 15 post-breeding
Authors: DesCoteaux Luc , Carriere Paul D. , Bigras-Poulin Michel
Published: March 2023

A field study was conducted between February and November 1995 using 139 Holstein cows to determine the accuracy and the usefulness of the ECF Dip Stick Test performed between days 11 and 15 post-breeding. Results of the ECF tests were compared to pregnancy diagnosis after 25 days post-breeding using ultrasonography and transrectal palpation. The apparent conception rate of the study population based on transrectal palpation was 38%. The ECF test sensitivity, specificity, positive and negative predictive values were 81%, 26%, 40% and 69%, respectively. The Kappa value (0.06; 95%CI -0.19 to 0.30) demonstrated no agreement between the ECF test and the final pregnancy status of dairy cows. These results would indicate that the ECF test is not a good predictor of pregnancy because the proportion of false positive results was high at 46% (64/139). Furthermore, the accuracy of the test to detect open cows is not acceptable with the high proportion of false negative tests of 31% (10/32). This finding would indicate that 19% (10/53) of the cows diagnosed pregnant rectally were misdiagnosed as non-pregnant by the ECF test. Finally, many factors such as the incubation time, the personal assessment of the test reaction and the source of light can also affect the ECF test reading. Based on the current technology, the authors would not recommend the use of the ECF test to help dairy producers reduce non-productive days.
Genetically Modified Organisms
Authors: Lindberg Robert A. , Phibbs Paul V.
Published: March 2023

Tremendous advances in the life sciences have paved the way for the development of a powerful array of new biotechnologies. As a consequence, the promise of the genetic manipulation of food animals for social benefit is now becoming a reality. This paper is intended to provide the bovine practitioner with a brief introduction to biotechnology, genomics, bioinformatics, gene mapping, cloning, genetically modified organisms and transgenic animals. Relevant recent advances are discussed in light of their potential impact on the beef, dairy and veterinary industries. The paper concludes with discussions of the distribution of regulatory responsibilities and the challenges facing the widespread adoption of these technologies in food production.
Case report
Authors: Kirkpatrick M. A. , Timms L. L. , Kersting K. W. , Kinyon J. M.
Published: March 2023

In the last three years, veterinary practitioners from Iowa, Minnesota and Wisconsin, USA, have reported, with increased frequency, a peracute, segmental haemorrhagic enteritis in mature dairy cattle. Based on these reports, clinicians at Iowa State University have begun to suspect Jejunal Haemorrhage Syndrome (JHS) as a new emerging disease syndrome. The morbidity rate for this disease has been sporadic, and mortality approaches 85-100% due to the peracute nature and severity of this disease. There are frequently no prodromal signs and the mature cow is found dead, or an individual cow is found down and in systemic collapse. Clinical signs include sternal recumbency, diaphoresis, enophthalmia and signs of shock due to occlusion of the small intestine. Ballotment of the standing cow in the lower right abdominal area can elicit a pronounced fluid slosh, due to backup of ingesta and fluid behind the occlusive lesion. Signs of abdominal pain include bruxism, vocalization, treading and kicking at the abdomen. At necropsy, segmental lesions localized to the jejunum are observed. These areas consist of frank haemorrhage and immediate clotting, forming a functional occlusion of the small intestinal lumen. Necrosis of the lumen may or may not be apparent. In April 1999, the Veterinary Diagnostic and Production Animal Medicine Department at the Iowa State University College of Veterinary Medicine was asked by a northeastern Iowa veterinarian to investigate recurring sporadic peracute death losses. Examination of affected cattle, production records, rations and post-mortem results led investigators to conclude that a variant of Clostridium perfringens, specifically type A, should be considered further as a possible cause of this disease syndrome. Recommendations for investigation of a problem herd are discussed. Specific items of increased risk in this particular herd included an association between increased milk production and death loss, an increased incidence rate associated with higher soluble carbohydrate feeding rates, and disease following re-introduction of culture-positive alfalfa haylage. There appear to be gut motility aberrations, evidenced by intussusceptions in tandem with Jejunal Haemorrhage Syndrome lesions.
Half-life for maternally derived immunoglobulin G anti-viral antibodies in data from an observational field study
Authors: Mechor G. D. , Virtala A.-M.K. , Dubovi E. J. , Grohn Y.T.
Published: March 2023

Using data for 161 calves from a matched case control study nested in an observational prospective cohort study, the half-life of virus-specific maternal serum antibodies was estimated. Each calf had virus-neutralizing antibody titres measured against bovine viral diarrhoea virus (BVDV), infectious bovine rhinotracheitis, parainfluenza 3, and bovine respiratory syncytial viruses determined postcolostrally, and at one or two time points later in life (but before 100 days of age). In this calf population, few calves were infected with viruses, because only 16 virus isolations from 15 animals were obtained and the population showed declining titres for viruses. The half-life for virus-specific antibodies was estimated as 23 days or less (95% confidence interval [CI], 21 to 26 days). This corresponds to the half-life for IgG found in many other studies with different study designs. If the three calves persistently infected (PI) with BVDV and/or five suspected-BVDV-PI-calves were excluded, the estimated half-life did not change. If samples from calves >30 days of age were excluded from the analysis, the half-life was determined to be 12 days (95% CI, 10 to 17 days).
Growth performance of cattle following percutaneous liver biopsy utilizing a Schackelford-Courtney biopsy instrument
Authors: Rogers Glenn M. , Capucille Dawn J. , Poore Matthew H. , Maas John , Smallwood James E.
Published: March 2023

Percutaneous liver biopsy has been utilized routinely in cattle as a diagnostic and research tool. However, there is little information on the effect on post-procedural performance. This paper describes a modified technique utilizing a Schackelford-Courtney bovine liver biopsy instrument, which generally obviates the need for multiple entries. Two trials were performed to evaluate post-procedural growth performance. In Trial 1, performed on finishing cattle, average daily gain (ADG) from the date the procedures (liver biopsy, ruminocentesis, orogastric intubation) were performed through the end of the 120-day finishing period was not different (p>0.25). However, calves that underwent the procedures had lower ADG, dry matter intake (DMI) and gain-to-feed ratio (G:F) (p<0.01) at Day 7 than calves that did not undergo the procedures. In Trial 2, a 112-day pasture study using stocker heifers, there were no significant differences at any weigh day (7, 28, 56, 84, 112) between liver-biopsied and non-biopsied groups. Results of the second trial suggest that differences seen in Trial 1 at Day 7 could have been related to other procedures performed concurrently (ruminocentesis, orogastric intubation), rather than the liver biopsy itself. In both studies, percutaneous liver biopsy was a relatively safe and effective procedure with minimal complications.
Survey of Minnesota dairy veterinarians on the occurrence of and potential risk factors for Jejunal Hemorrhage Syndrome in adult dairy cows
Authors: Godden Sandra , Frank Rod , Ames Trevor
Published: March 2023

The Veterinary Teaching Hospital at the University of Minnesota, USA, has, over the past two years, recognized an increased rate of cases of adult dairy cattle with a disease syndrome described as "jejunal haemorrhage syndrome". Two separate surveys were administered to Minnesota bovine practitioners, one by mail in March 2000, and the second at the annual conference of the Minnesota Veterinary Medical Association in February 2001. The objectives of these two surveys were: (1) to gather preliminary data describing how frequently this disease syndrome is being diagnosed by dairy veterinarians and (2) to generate some hypotheses as to potential cow or herd management-related risk factors which may warrant future study. For the two surveys, between 50 and 59% of survey respondents reported having diagnosed one or more cases of jejunal haemorrhage syndrome (JHS) in the previous 12-month period. Many of these veterinarians reported its occurrence in multiple client herds, and between 40 and 56% reported the diagnosis of multiple cases in individual herds. The majority of respondents indicated that they believe this is an important disease syndrome that deserves further study. Potential cow and management-related risk factors for JHS that warrant future study include parity, stage of lactation, season, herd size and feeding management system.
Milk antimicrobial residues in Holstein dairy cattle treated for toxic puerperal metritis
Authors: Smith Billy I. , Donovan G. Arthur , Rosco Carlos A. , Elliott Jessie
Published: March 2023

The objective of this study was to determine the presence of antimicrobial agents in milk and the time milk from cows treated for toxic puerperal metritis remained positive for antimicrobial residues. 51 Holstein dairy cows were divided into 3 treatment groups: Group 1 was treated with penicillin; Group 2 was treated with penicillin and tetracycline; and Group 3 was treated with ceftiofur sodium. Cows in Groups 1 and 2 received a daily intramuscular injection of procaine penicillin G at the standard farm-wide dose of 18 million units for 5 consecutive days, nearly 4 times the recommended dose of 3000 U/lb (6600 U/kg). In addition, cows in Group 2 were infused with 6 g of oxytetracycline diluted in 75 ml of sterile water on days 1, 3, and 5. Cows in Group 3 received a daily intramuscular injection of ceftiofur sodium at a standard farm-wide dose of 1 g for 5 consecutive days. Milk samples were collected on day 1, before the first dose of antimicrobial agent was administered, and on days 6 through 12 after the final day of treatment with antimicrobial agents. LacTek B-L (beta-lactam), LacTek TC (tetracycline), and LacTek CEF (ceftiofur) test kits were used to determine penicillin, tetracycline, and ceftiofur sodium residues, respectively, in milk samples. All 3 test kits used in this study have been phased out of production and are no longer available. Milk from 9 of 17 cows treated with penicillin was positive for beta-lactam residues for an average of 3.44 days post-treatment. In a separate group, 6 of 17 cows treated with penicillin were positive for beta-lactam residues for an average of 3.66 days post-treatment. Nine of 17 cows treated with oxytetracycline were positive for tetracycline residues for an average of 1.22 days following treatment. No milk residues were detected in cows treated with ceftiofur sodium. Antimicrobial residues were found in milk from cows treated with penicillin and oxytetracycline for 1 to 7 and 0 to 3 days, respectively, from the last day of treatment. In this study, milk from cows treated with penicillin tested positive for residues longer than expected and longer than the labelled withholding time. Antimicrobial screening may be necessary to prevent food contamination.
Dairy advisory teams
Authors: Heald C. W. , Hutchinson L. J. , Holden L. A.
Published: March 2023

Dairy Advisory Teams (DATs) improve farm management success when producers and advisors have the skills and attitude to make them work effectively. Basic team concepts are taught during team training workshops and in follow-up communications. Teams learn to recognize individual farm values, objectives and constraints before identifying areas in which improvements could be made. Teams are selected from people with skills and abilities that complement farm goals. An advisor who is not part of the owner/management group organizes and runs the team meetings in consultation with the owner. Advisors with team facilitation skills and experience make the best coordinators. Teams formulate action plans that are critical to success. Regular team meetings (monthly or bi-monthly with experience) increase the ability of farm advisors to monitor and make midcourse adjustment to farm plans. Farm owners make all decisions while benefiting from timely diverse advice from multiple professionals. Our study confirms that veterinarians are one of three critical team advisors and provide essential advice for teams when health information is integrated into the farm decision-making processes. Further, this study suggests that certain elements are key to success of a dairy advisory team. Teams most likely to continue after the first year tended to advise larger, better-managed herds. They had producers dedicated to the team process, experienced coordinators or new coordinators that adhered to the team process. Successful advisory teams functioned for multiple years, had larger teams and had goals that were more strategic (long term) than tactical (immediate). Smaller herds with DATs made faster progress on several indicators than larger herds, primarily because they were further behind initially Therefore, DATs can target smaller herds and make significant progress. Four to five team members appears to be the practical size for herds up to 150 cows, and six to seven team members for herds milking over 200. Team size is not as critical to success as the dedication of the producer and the leadership ability of the coordinator. Although herds with production challenges made greater progress, producer attitudes and coordinator effectiveness contributed most to sustainability. The financial and professional rewards for consultants may be greater when working with larger farms and dedicated producers.
Pre-colostral antibodies to Neospora caninum in beef calves following an abortion outbreak and associated fall weaning weights
Authors: Waldner Cheryl L.
Published: March 2023

Published reports have suggested that Neospora caninum infection may decrease milk production in dairy cows and affect rate of gain and feed efficiency in feedlot steers. This study examined whether there was an effect on the weaning weights of commercial beef calves. The outbreak involved a family-owned, 350-head cow-calf beef herd. Calves that developed antibodies to N. caninum during gestation were compared to calves with no evidence of infection. Blood samples were collected from calves before colostrum ingestion and from all cows after calving. Sera were analysed using a commercially available enzyme linked immunosorbent assay for N. caninum. Detailed individual calving records, birth, and weaning weights were available for all calves. Of the 180 samples collected from the cows and first-calf heifers after calving, 153 (85%) were positive for N. caninum. Seventy-five (67%) blood samples collected from 112 calves prior to colostrum ingestion also had positive antibody titres for N. caninum. Fall calf weights for calves with antibodies to N. caninum at birth were insignificantly different than those of calves with no antibodies (difference, -9.2 lb [-4.18 kg]; 95% CI, -31.3 to 12.8 lb), after adjusting for calf sex, dam age, calf birth weight, calf age at weighing, and sire group.