Adherence as a Prerequisite for Infection of the Bovine Mammary Gland by Bacteria

Using a simple in vitro test it was demonstrated that staphylococci, Streptococcus agalactiae, and micrococci, the species of bacteria which are commonly isolated from udder infections, adhered to mammary gland epithelial cells readily and in large numbers. Some strains of organisms which are associated with sporadic outbreaks or occur less commonly, like Str. dysgalactiae and Str. uberis, adhered moderately. Escherichia coli, Klebsiella spp., Corynebacterium pyogenes, C. bovis, Str. bovis, and Str. faecalis, species which are isolated occasionally, adhered poorly. From these studies, it appears that selective adherence of bacteria to the epithelial cells is a factor contributing to the ability of organisms to infect the mammary gland and may, therefore, be considered an important stage in the pathogenesis of bovine mastitis.     

Prevalence of pathogens causing subclinical mastitis in 15 dairy herds in the Republic of Ireland

: Milk samples from 285 cows in 15 dairy herds were collected for bacteriological analysis. Cows were selected on the basis of a somatic cell count (SCC) exceeding 200,000 cells per ml at the three most recent milk recordings prior to sampling. Staphylococcus aureus and Streptococcus uberis were the predominant isolates accounting for 21% (n = 61) and 19% (n = 53) of isolates, respectively. Streptococcus uberis was more frequently isolated from split-calving herds than from spring-calving herds and this difference was statistically significant (P < 0.005). Herds with suboptimal housing had a significantly greater prevalence of S. uberis than did herds where housing was adequate (P < 0.005). The isolation rates for S. aureus was significantly greater in herds where parlour hygiene was suboptimal (P < 0.05).     

Reduced Milk Production in Udder Quarters with Subclinical Mastitis and Associated Economic Losses in Crossbred Dairy Cows in Ethiopia

The objective of the study was to estimate the losses associated with subclinical mastitis (SCM) in crossbred dairy cows in the Central Highlands of Ethiopia. A split udder investigation was performed with 30 cows to determine production losses associated with SCM. Each quarter of the study cows was examined using the California Mastitis Test (CMT) and quarter milk production was measured over a period of 8 days. Production losses were determined for different CMT scores by comparing production of quarters with CMT score 0 to quarters with CMT scores trace, 1, 2 and 3, respectively. Using data from a recently published study, economic losses were determined for different farm sizes and production subsystems by multiplying the prevalence of the respective CMT scores with the production losses associated with these CMT scores. Mean quarter milk production was 0.82 + 0.40 kg per milking in the split udder trial. Milk production was reduced by 1.2%, 6.3%, and 33% in quarters with CMT scores 1+, 2+, and 3+, respectively. Using data from the published study, a quarter with SCM lost an average of 17.2% of its milk production. Production losses associated with SCM were estimated at 5.6% for the Addis Ababa Milk Shed. Stratified losses were highest (9.3%) in urban dairy farms (UDF) and small-scale farms (6.3%). The estimates of the financial losses ranged from US$29.1 in dairy herds in secondary towns (DHIST) to US$66.6 in UDF. A total loss of US$38 was estimated for each cow per lactation. Reducing mastitis in UDF (highest prevalence) to the level of DHIST (lowest prevalence) could reduce the loss by US$35. As this does not include costs associated with treatment or culling of diseased cows, this figure probably underestimates the possible benefits of control measures.     

Characteristics of Peri-urban Dairy Herds of Bobo-Dioulasso (Burkina Faso)

Peri-urban dairy cattle farms within 50 km of Bobo-Dioulasso were studied to assess herd type, disease incidence, management, feeding and breeding strategy. Out of 417 cattle farmers, 42% had dairy objectives and were studied. Among these peri-urban dairy farmers, 60% were settled, 36% semi-settled, and 4% transhumant. In total, they held 4558 dairy cows, of which 32% lactated during the study. The prevalence of mastitis (55%) increased (p<0.05) with herd size. Advanced strategies for supplementary feeding and breeding were most frequent in small herds (<30 cattle). None of the large herds (>60 cattle) had advanced breeding strategies. Bulls and cows were culled at younger ages in herds with better breeding strategy. Overall, this resulted in higher individual milk offtake in small herds (2.46 L/day) compared with large herds (1.25 L/day). Pure breeds were rarely used, and the presence of Bos taurus baoulé naturally selected for trypanotolerance was low. The prevalence of trypanosomosis (40%) in herds dominated by Bos indicus zebu and Méré (Zebu x Baoulé) is an argument for maintenance of biodiversity and selection of Baoulé for milk production.     

Risk Indicators Associated with Subclinical Mastitis in Smallholder Dairy Cows in Tanzania

Smallholder dairy farmers in Tanzania appear to be unaware of the subclinical mastitis situation in their cows. A cross-sectional study was carried out between June and September 2002 on smallholder dairy herds in the Dar es Salaam region. The study objectives were to establish the prevalence of subclinical mastitis and related risk indicators, and to assess their contribution to the occurrence of subclinical mastitis. Three field procedures based on the principles of herd health and production management were followed: clinical, farm and data inspection. The California mastitis test (CMT) was carried out on quarter milk samples to determine the prevalence of subclinical mastitis. A total of 182 lactating cows from 62 herds were investigated. Clinical inspection indicated that 3.8% of the lactating cows had clinical mastitis. Subclinical mastitis was detected in 90.3% of lactating cows screened. Farm inspection revealed that water scarcity, barn size, residual suckling, single udder-towel and dairy labourers as the most substantial (p < 0.05) risk indicators. Although most of the risk indicators studied were not found to be statistically significantly associated with the occurrence of subclinical mastitis, possibly owing to sample size and the presence of confounders, the epidemiological need to address such risk indicators cannot be overemphasized.     

Italian University System has to Match Educational Needs in Adherence to European Standards and Professional Scenario

The effect of a water-soluble fraction (WSF) of a non-pathogenic strain of Mycobacterium phlei was studied in bovine subclinical mastitis (SCM) by measuring the myeloperoxidase and acid phosphatase enzyme levels in the milk leukocytes. Forty-five cows were divided into three equal groups. Group I, consisting of 15 healthy cows, served as the control, whereas groups II and III each contained 15 cows with subclinical mastitis on the basis of a positive reaction in the California mastitis test (CMT). The cows in group II received 100 microg of WSF in 5 ml sterile phosphate-buffered saline, pH 7.4 (PBS) once only, while those in group III received 5 ml sterile PBS daily for 7 days, both treatments being given by the intramammary route. Observations were made up to 30 days after treatment (AT). The CMT of the healthy milk was negative (0), whereas it ranged between 1 and 2 points in SCM. The somatic cell count (SCC) increased significantly (p < 0.05) on day 3, then fell steeply from day 7 up to day 30 AT in the cows in group II. A steady decrease in the total bacterial count (TBC) was observed in the group treated with WSF but the bacterial counts remained high in the groups treated with PBS. The mean acid phosphatase level was enhanced by 119% on day 3 AT in group II but only by 18.7% in the cows in group III. The mean myeloperoxidase level was enhanced by 100% in the cows in group II but only by 18% in those in group III on day 3 AT. This significant reduction in the bacterial load in infected cows caused by intramammary infusion of WSF may be due to activation of the microbicidal activity of the neutrophils, but this requires confirmation.     

富平奶山羊临床型乳房炎病原菌的分离鉴定

为探明奶山羊感染乳房炎病原菌的情况,为其防治提供参考,对富平县3个不同乡镇的79头患病奶山羊和118份奶样进行分离鉴定。结果表明:样品中共检测出革兰氏阴性杆菌、革兰氏阳性杆菌、革兰氏阳性球菌和真菌4类病原菌,分离出7种、126个菌株。其中,大肠杆菌36株,占28.5%;金黄色葡萄球菌28株,占22.2%;绿脓杆菌23株,占18.3%;链球菌21株,占16.7%;变形杆菌8株,占6.3%;蜡样芽孢杆菌6株,占4.8%;酵母菌4株,占3.2%。结论:大肠杆菌、金黄色葡萄球菌、绿脓杆菌、链球菌是富平县奶山羊乳房炎的主要致病菌。     

Equine mammary gland disease with a focus on botryomycosis: A review and case study

Mammary gland problems occur incidentally in horses and one of the rarer conditions is botryomycosis (bacterial pseudomycosis, bacterial granuloma, staphylococcal pseudomycetoma). This article includes a short review of equine mammary gland problems inappropriate lactation, mastitis and neoplasia and botryomycosis, and additionally 2 clinical cases of botryomycosis of the udder resulting from Staphyloccocus aureus infection will be discussed. Both cases involved nonpregnant, nonlactating mares referred for chronic mammary inflammation with draining abcessation. In both mares, botryomycosis caused by S. aureus was confirmed by histopathology and a bacterial culture. Both mares recovered fully after surgical hemimastectomy under general anaesthesia.     

夏季奶牛乳房炎的综合防治措施

奶牛乳房炎是危害奶牛生产的一项重大疾病,是奶牛生产中的常见病和多发病,尤其在夏季发病率很高。笔者通过查阅大量文献资料和总结自身实践经验,对夏季奶牛乳房炎的有效防治进行综述,以供同行参考。