A genomic study on mammary gland acclimatization to tropical environment in the Holstein cattle

Tropical Animal Health and Production - This study aims at identifying mammary gland genes expressed in Brazilian Holstein cattle produced under tropical conditions, as compared to the Portuguese...     

Simultaneous vaccination of cattle against foot-and-mouth disease and rinderpest

Summary A total of 118 local cattle in the Sultanate of Oman were divided into three groups, one which received a trivalent inactivated foot-and-mouth disease vaccine, another which received attenuated tissue culture rinderpest vaccine and a third which received both vaccines simultaneously at separate sites on opposite sides of the neck. The serological response to vaccination was monitored at day 0,21 and 42 in virus neutralisation tests. The simultaneous administration of the two vaccines produced no ill effects and the serological responses did not differ significantly from the response to either vaccine given separately.

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Resumen Un total de 118 bovinos en Oman se dividieron en tres grupos, recibiendo el primero una vacuna trivalente inactivada de aftosa, el segundo recibió una vacuna preparada en cultivos celulares y atenuada, recibiendo el tercer grupo ambas vacunas simultáneamente en el lado derecho e izquierdo de la tabla del cuello. La respuesta serológica a la vacunación se estudió los días 0,21 y 42 mediante la técnica de neutralización viral. La administración simultánea de las dos vacunas antes mencionadas, no produje efectos indeseables y la respuesta serológica no difirió significativamente de aquella obtenida mediante la aplicación de ambas vacunas en forma separada.

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Résumé 118 bovins d’origine locale du Sultanat d’Oman ont été divisés en trois groupes: l’un a re?u un vaccin anti-aphteux trivalent, un autre le vaccin antibovipestique atténué sur cultures de tissu, le troisième les deux vaccins en même temps de part et d’autre du cou. La réponse sérologique à la vaccination a été évaluée aux jours 0,21 et 42 par des tests de séroneutralisation. L’administration simultanée des deux vaccins ne produit pas d’effet néfaste et les réponses sérologiques ne différent pas de manière significative de la réponse fournie par l’un des vaccins séparément.

     

Isolation of mycoplasma species from the lower respiratory tract of healthy cattle and cattle with respiratory disease in Belgium

Between 1997 and 2000, a total of 150 healthy cattle and 238 animals with respiratory disease were examined for six Mycoplasma species. Attempts were made to detect Mycoplasma canis, Mycoplasma dispar and Ureaplasma diversum in calves with recurrent disease, and all three of these species were identified in calves with recurrent disease and in healthy lungs. In healthy calves, 84 per cent of bronchoalveolar lavage fluids were mycoplasma free; when cultures were positive, Mycoplasma bovirhinis was the only species isolated. Mycoplasmas were isolated from 78 per cent of animals suffering recurrent respiratory disease and from 65 per cent of acute respiratory cases. Mycoplasma bovis was isolated from bronchoalveolar lavages from 35 per cent of calves suffering recurrent respiratory disease, and from 50 per cent of acute cases, and from 20 per cent of pneumonic cases examined postmortem. M bovis was associated with other Mycoplasma species in 44 per cent of cases. M dispar was also isolated from 45.5 per cent of calves suffering recurrent respiratory disease, often in association with M bovis. M canis was identified for the first time in diseased Belgian cattle. Other mycoplasmas, including Mycoplasma arginini, Mycoplasma alkalescens and U diversum, were isolated less frequently. Associations between mycoplasmas and other pathogens were often observed. Among lungs infected with Pasteurella and/or Mannheimia species, more than 50 per cent were mixed infections with M bovis.     

Bovine respiratory disease in feedlot cattle: environmental, genetic, and economic factors

The objective of this study was to characterize genetic, environmental, and economic factors related to the incidence of bovine respiratory disease (BRD) in feedlot calves. Records from 18,112 calves representing 9 breeds (Angus, Braunvieh, Charolais, Gelbvieh, Hereford, Limousin, Pinzgauer, Red Poll, and Simmental) and 3 composite types (MARC I, MARC II, and MARC III) over a 15-yr period (1987 to 2001) were evaluated. Disease incidence was observed and recorded by station veterinary and technical staff. The incidence of BRD varied across years, with the annual observed incidence ranging from 5 to 44%. From 1987 to 1992, the annual average incidence generally exceeded 20%. However, in later years the annual incidence did not exceed 14%. The epidemiological pattern indicated that BRD infection increased dramatically after 5 d on feed and remained high until approximately 80 d on feed. Previous BRD infection during the preweaning period did not influence subsequent BRD infection in the feedlot. Steers were more likely to become sick with BRD than heifers; castration before entry in the feedlot may be a predisposing cause. Few significant differences among breeds were detected for BRD incidence. Adjusted solutions from mixed model analyses indicated that Herefords were generally more susceptible to BRD infection (P < 0.05) than MARC I and III composite types. Composite breed types had similar susceptibility compared with other purebred breeds. Mortality associated with BRD was greatest in Red Poll calves (9%) compared with the average over all breeds (4%). Estimates of heritability for resistance to BRD ranged from 0.04 to 0.08 +/- 0.01. When the observed heritability was transformed to an underlying continuous scale, the estimate increased to 0.18. Selection for resistance to BRD could be effective if phenotypes for BRD resistance were known. Thus, development of an inexpensive and humane method of challenging animals with BRD to determine resistance would be an important step in reducing the incidence of BRD. This study also demonstrated that producer-collected field data could be used for selection against this disease. The economic loss associated with lower gains and treatment costs for BRD infection in a 1,000-cattle feedlot was estimated as dollar 13.90 per animal, not including labor and associated handling costs.     

Some observations on disease incidence among dairy cattle in North Taranaki

Extract

In recent years there has been increasing interest in schemes for disease eradication and preventive medicine. Any such schemes depend upon a clear definition of the expected animal heath risk in a particular area and season, but precise information on disease incidence is still conspicuous by its absence in veterinary literature, and much of what is available has relied upon informed guesswork. The Animal Health Laboratories are now undertaking electronic data processing of laboratory reports to help fill this gap in our knowledge. However, this will only supply data on the type of case from which samples are submitted. These data will have undergone a double process of selection and deletion, first by the farmer selecting the cases for which he will summon professional assistance, and secondly by the veterinary practitioner selecting the cases for which he requires laboratory investigations.     

Metritis complex in Michigan Holstein-Friesian cattle: incidence,descriptive epidemiology and estimated economic impact

Twenty-two Michigan dairy herds participating in a computerized herd health program were studied to determine the incidence and epidemiologic characteristics of metritis. Of 3773 lactations studied, 18% of the cows developed metritis at least once during the lactation. Metritis was reported most frequently immediately following calving. No clear pattern of association with age or season was demonstrated. A estimate was made of the extra cost associated with a cow treated for metritis. After including the effect on reproductive efficiency, milk production, cost of medication and losses due to culling, the total cost estimate was $106.00 for a lactation with metritis.     

慎防牛呼吸系统疾病综合征吞利毁场

牛呼吸系统疾病综合征(BRDC)是由病原体感染、应激刺激和机体抵抗力下降等病因共同作用引起牛的一种以发热、神差纳少和鼻炎、气管炎、支气管炎、肺炎为主要临床表现的一类传染性疾病的总称,又被称为“运输热。本病多在秋冬季或春夏之交呈地方性或散发性流行,常以多种病原体相互协同作用的感染、复杂的病情导致犊牛(特别是45日龄内的犊牛)和新引进牛相当高的发病率和大批量的死亡而侵吞养牛的利润甚至推毁养牛场,是一个严重困扰养牛业的世界性问题。作者综述了BRDC的危害、病因、快速诊断,并从养牛生产实际出发较为详细地阐述了BRDC的预防与治疗技术措施,对防控BRDC有一定的实际指导意义。     

Influence of breed, heterozygosity, and disease incidence on estimates of variance components of respiratory disease in preweaned beef calves

The objective of this study was to characterize genetic and environmental factors influencing bovine respiratory disease (BRD) in beef cattle. Records from nine purebred and three composite breeds and a variety of F1 and three-way crosses, including the progeny of 12 additional different sire breeds produced over a 20-yr period (1983 to 2002), were evaluated for breed and heterozygosity effects on the observed incidence of BRD. Heterozygosity fractions for calves and dams were defined by generalized breed origins: British, Continental, and tropically adapted. Variance components were estimated for each pure and composite breed, and across all breeds and crossbreeds. The effect of incidence of observed BRD was determined by comparing groups of low and high years of incidence. Respiratory disease in this herd followed a standard epidemiological pattern of initial introduction, reaching an epidemic stage at 70 to 170 d of age, followed by a period of rapid decrease to weaning. Estimates of heritability of incidence of BRD were low, ranging from 0.00 to 0.26, with overall estimates of 0.07 and 0.19 depending on the data set analyzed. The highest incidence of BRD in preweaned calves occurred in the Braunvieh breed (18.8%). The genetic correlation between the direct and maternal genetic effects was generally large and negative, suggesting dams genetically superior for resisting BRD raise calves that are more susceptible. Perhaps maternally superior dams provide passive immunity to their calves, which delays the development of the calves' direct immune system, making them more prone to BRD during the preweaning period. Heterozygosity of calves decreased the incidence of BRD compared with purebred cattle. Calves that were Continental x British or tropically adapted x British breeds had a lower incidence of BRD than did calves of British x British breeds. As the annual incidence of BRD increased, there was an associated increase in the heritability estimate. The estimated heritability based on an underlying continuous scale was large (h2 = 0.48), inferring response to selection for BRD resistance could be large if the phenotype for BRD resistance was known.     

Epididymitis in rams: effect of vaccination and culling on the clinical incidence of the disease.

Ram epidiymitis caused by Brucella ovis can be effective controlled by an annual program combining rigorous culling clinically affected animals and appropriate vaccination of the remaining animals. Yearling rams purchased or saved as replacement breeders should be immunized at 4-5 months of age by two injections of Br. ovis bacterin spaced 3-6 weeks apart. Annually, approximately one month prior to the breeding season, all rams, replacements and older breeders as well, should be carefully examined by palpation of the scrotal contents. Every ram evidencing an abnormality should be culled as a breeder. All the remaining rams should receive a "booster" injection of Br. ovis bacterin.     

Efficacy of danofloxacin in the treatment of respiratory disease in European cattle

The efficacy of an injectable formulation of danofloxacin (180 mg/ml) in the treatment of naturally occurring bovine respiratory disease was evaluated in field studies on farms in France, Ireland and the United Kingdom. Cattle aged one week to 15 months with clinical respiratory disease were randomly allocated to treatment with 6 mg/kg danofloxacin or 10 mg/kg tilmicosin, administered by a single subcutaneous injection on day 0. A second injection of danofloxacin was administered on day 2, only if predefined clinical criteria were met. Mannheimia haemolytica, Pasteurella multocida and Haemophilus somnus were isolated from pretreatment nasopharyngeal swabs taken on all the farms. After the treatment, there was a more rapid improvement in the clinical response of the 178 animals treated with danofloxacin by day 2 (P < 0.01) than in the 90 treated with tilmicosin. For both treatments, there were similar significant (P < 0.001) reductions in the mean rectal temperature and severity of clinical signs of abnormal respiration and depression, on days 4 and 10 compared with day 0; 78.1 per cent of the animals treated with danofloxacin and 78.5 per cent of those treated with tilmicosin completed the studies. Danofloxacin 18 per cent was clinically safe and as effective as tilmicosin in the treatment of bovine respiratory disease.     

Comparative efficacy of tulathromycin, tilmicosin, and florfenicol in the treatment of bovine respiratory disease in stocker cattle

The therapeutic efficacy and field safety of tulathromycin were evaluated in stocker calves with undifferentiated bovine respiratory disease (BRD) in three field studies conducted over two consecutive grazing seasons in Nebraska. Eight hundred calves exhibiting clinical signs of BRD and with rectal temperatures of 104 degrees F or higher were treated with tulathromycin (n = 340), florfenicol (n = 240), or tilmicosin (n = 220) and evaluated for approximately 60 days. Florfenicol and tilmicosin were administered as single SC injections according to labeled dosage. Tulathromycin was administered as a single SC injection of 2.5 mg/kg. In all three studies, the cure rate of calves 60 days after treatment with tulathromycin was significantly higher (P < or = .05) than that of calves treated with florfenicol or tilmicosin. Suspected adverse reactions were not reported for any of the study drugs. Tulathromycin proved to be significantly more effective than either florfenicol or tilmicosin in the treatment of BRD in stocker calves.     

A study of foot disease of dairy cattle in quebec

A 12 month survey of the different diseases of the digital region of dairy cattle was conducted in the province of Quebec in order to determine the relation between the frequency of the main digital lesions and different factors involved.

Sole ulcer, white zone disease and erosion of the bulb represented 88.6% of all the lesions. The majority of the cases were recorded during the pasture season. An initial peak of prevalence was found in two year old heifers but cows were mainly affected between the ages of five to eight years. Sixty-six percent of the lesions appeared during the first three months of lactation.

     

A pathogenesis study of foot-and-mouth disease in cattle, using in situ hybridization.

Eight calves were exposed in an aerosol chamber to nebulized foot-and-mouth disease virus. Two control animals were exposed in a similar manner to cell culture media only. Animals were euthanized at intervals and various tissues examined by in situ hybridization using a biotinylated RNA probe corresponding to a portion of the viral gene coding for the polymerase enzyme. By this technique large amounts of viral nucleic acid were found in coronary band, interdigital cleft and tongue as early as six hours postexposure, indicating a very rapid delivery from the portal of entry to the predilection sites for lesion development. This occurred well before the onset of viremia which by virus isolation was not detectable until 30 hours postexposure. The in situ hybridization signal in these tissues decreased in intensity and extent with time to focally positive areas, occasionally surrounding a vesicle. Other epidermal sites not normally thought of as sites for foot-and-mouth lesion development, such as carpus and eyelid, also had some viral nucleic acid detectable at various time intervals. In the lung by in situ hybridization, alveolar septa had viral nucleic acid early in infection (6-18 h postexposure) while later (36-96 h postexposure), the in situ hybridization signal was prominent in alveolar macrophages.