Developing new veterinary services in milk quality: a review of a recent mastitis risk management co-development in Australia

A new veterinary service to promote ongoing, incremental improvements in the risk management of mastitis and milk quality was developed between 2005 and 2008. This was designed to enhance the relationship between the farmer and advisor, as an extension of the Countdown Downunder programme, Australia's national mastitis and milk quality programme. This service was co-developed between the Countdown Downunder programme team and a core development group of veterinarians involved with trialling the service, and farmers and social researchers. The service, known as Countdown MAX, involved advisory input at the planning stage, a written risk management plan, multiple engagements between the farm team and advisor for tracking and re-planning, and a service fee. Risk management resources (modules) were developed to be employed at the drying-off and calving periods, and during lactation. During the development and implementation phase eight veterinary practices conducted Countdown MAX consultations on 55 farms. Eighty-eight Countdown MAX modules were delivered in total, with 55% of farms completing more than one module but only 38% of modules reviewed successfully. A social research project examined the implementation of the Countdown MAX service in participating veterinary practices during the development phase. Findings of the project were that the successful uptake of a new mastitis service into a veterinary practice was enhanced through uptake by practice owners of the concept, the formation of a written practice plan, adequate communication and explanation of the new service to all staff, logistical support for the service within the practice, and transfer of mastitis expertise within the practice.     

Mastitis control programme in the developing dairy industry of tropical lowland Bolivia

Mastitis is an important disease in developing dairy industries. This paper describes a commercial mastitis control programme in Santa Cruz, Bolivia, based upon the five-point mastitis control plan and bulk tank somatic cell count (BTSCC) monitoring. Twelve farms which participated on the programme for 6 years are considered. Mean annual BTSCC fell steadily from 1200000 cells/ml to 461000 cells/ml over this time. This progressive improvement was probably a result of increasing use of and attention to detail in mastitis control practices. The control of subclinical mastitis improved in both hand-milked and machine-milked herds, though hand-milked herds consistently produced milk of higher BTSCC. The mastitis programme did not appear to influence the incidence of clinical mastitis. The paper concludes that a simple mastitis programme based on the five-point plan and BTSCC monitoring can be commercially implemented and effectively control subclinical mastitis in a tropical, developing country.     

奶牛隐性乳房炎的调查分析

采用体细胞计数(SCC)法对杨凌某奶牛场中60头不同胎次和泌乳时间奶牛隐性乳房炎进行检测,对引起乳房炎的可能诱因进行调查分析,研究该场奶牛隐性乳房炎的发病规律,为本病的防控提供参考。结果表明,受检奶牛隐性乳房炎的检出率为43.3%。1胎～2胎奶牛隐性乳房炎检出率为40.0%,3胎～4胎为46.7%,隐性乳房炎的检出率有随胎次增加而升高的趋势;泌乳时间少于200 d的泌乳牛隐性乳房炎检出率为27.6%,200 d～300 d的为36.4%,300 d～400 d的为41.7%,超过400 d的为50.0%,提示奶牛隐性乳房炎有随泌乳期升高的趋势。本调查显示,奶牛隐性乳房炎的发生与胎次和泌乳时间有显著的相关性,饲养管理和卫生条件是乳房炎发生的重要诱因。     

New Strategies to Prevent Mastitis

Bovine mastitis remains as the disease causing the biggest economic losses to the dairy industry, despite the intensive research and prevention measures at herd level carried out for decades. Antibiotics are widely used to combat mastitis, but focus should be shifted from treatment to more economical and efficient prevention. The bacteriological aetiology of mastitis has changed from contagious to environmental pathogens, which has reduced the efficacy of the traditional mastitis control strategies. Considerable progress in the understanding of epidemiology, immunology, diagnostics and pathogenesis of mastitis has been made. The modern molecular biological methods offer good possibilities for the research of the epidemiological and virulence aspects of bacteria, which may help in building‐up specific mastitis control strategies for dairy herds. Studies on the host response and relationship between somatic cell count and susceptibility to mastitis offer tools for genetic improvement of dairy cows. Biotechnological approaches for mastitis prevention are in the developmental stage, but many problems are associated, e.g. with vaccination of dairy cows against mastitis. Different methods of immunomodulation for the prevention of mastitis have shown promise in experimental trials, but the evidence is not yet enough to support commercial applications. Improving nutrition, housing and environment of dairy cattle are still crucial in the prevention of mastitis, especially during the most susceptible period after parturition. New milking techniques including robotic milking may provide better possibility for proper milking and improved udder health. Mastitis control should be part of the herd health programme in the dairy herds. In this paper, results from recent research and proposals for new prevention strategies in the field of mastitis are reviewed.     

过瘤胃甜菜碱对隐性乳房炎奶牛生产性能的影响

选择15头体细胞数在100万个/mL以上奶牛,随机分为3组,每组5头,分别在日粮中添加0g/d、18g/d和24g/d过瘤胃甜菜碱,研究其对隐性乳房炎奶牛产奶性能和体细胞数的影响。结果发现:对照组奶牛产奶量与试验前相比,下降了1.04kg,而试验组分别提高了0.52kg和0.88kg;乳脂率、乳蛋白等乳成分略有提高,但差异均不显著。添加过瘤胃甜菜碱组牛奶中体细胞数显著降低,与对照组相比,差异显著(P<0.05)。表明隐性乳房炎奶牛补饲过瘤胃甜菜碱,能够降低牛奶中体细胞数,提高奶牛产奶性能。     

体细胞计数及其在降低奶牛乳房炎发病率方面的应用

介绍奶牛体细胞计数的概念、特征、测量方法、体细胞值所受到的影响及其在乳制品行业的应用,尤其是在降低奶牛乳房炎发病方面,用体细胞值作为一种遗传性状进行选择以提高奶牛对乳房炎抗性的应用。     

Mastitis control measures used on some Minnesota dairy farms

Proven mastitis control procedures are available, but few studies have documented their rates of use on commercial dairy farms. This paper presents the results of a mail questionnaire on the use of mastitis control procedures and sources of information on mastitis control, which were administered in December 1981 and again in February 1984 to 213 Minnesota dairy farmers. Sources of information about mastitis control were also determined for the surveyed farms. Response rates to the questionnaire were 56.8% in 1981 and 51.2% in 1984. Herd average milk and butterfat production were higher and somatic cell counts lower on responder's farms than non-responders'. Teat dipping was practiced by approximately 75% of farmers responding to the questionnaire in both years. However, only about one third of respondents used teat dips containing effective disinfectants. Approximately 93% of respondents used dry period therapy (DPT) but less than one half of them treated all quarters of all cows at drying off and approximately one third of them complied with the recommended infusion practices. A combination of effective DPT and teat disinfection practices was used by approximately 15% of respondents in both years of the survey. Segregation of mastitic cows occurred on approximately 40% of respondent farms and milking machine function was checked at least annually on 50%. Participation in routine veterinary reproductive health programs was 51.2% in 1981 and 61.5% in 1984. In contrast, regular veterinary input for mastitis control was received by <5% of respondents in both years of the survey. Veterinarians were, however, identified by respondents as the most useful source of information on mastitis control.     

2019年呼伦贝尔地区奶牛产奶量及质量指标不同月份变化分析

旨在探讨内蒙古自治区呼伦贝尔地区不同月份荷斯坦奶牛乳成分、体细胞数和菌落总数的变化情况。试验共采集2019年1-12月14 354批次样本进行分析,以探索不同月份对奶牛产奶量、乳成分、体细胞数和菌落总数的影响。结果表明：呼伦贝尔地区荷斯坦奶牛产奶量在不同月份有变化,4-5月达到最高值,11月到次年2月最低,建议在该阶段做好奶牛冷应激防护;体细胞数在1-3月比较高,建议加强奶牛饲养管理,注意乳房炎防控;乳成分和菌落总数基本不受月份变化影响。     

A large scale mastitis control programme in Somerset.

The results of a mastitis control programme operated in south west England for three years are given. Farmers participating in the full mastitis control group agreed to treat each cow at drying off with 500 mg benzathine cloxacillin in each quarter, to have their milking machines tested and to correct any faults, and to practise teat dipping. Data covering cell counts, milk production, milk quality and clinical mastitis, were assessed from herds taking part in the programme. Cell counts were analysed from all 507 herds taking part in the programme. Milk production records for the full mastitis control group (188 herds) over a three year period are discussed, and these results compared with milk production figures from Milk Marketing Board records from herds in the south west of England which were carrying out no specific mastitis control programme. The milk quality data compare the findings in 159 herds in the full mastitis control programme with those in 247 herds in the partial and no mastitis control groups. Cases of clinical mastitis during the three year period were recorded in 73 herds in the full mastitis control group. The problems of applying the control routines are presented with observations on clinical mastitis, bulk milk cell count, milk production and milk quality. After three years, herds in the programme had on average increased milk production by 75 gallons a cow, achieved a 14.6 per cent reduction in the incidence of clinical mastitis, and improved the milk total solids percentage by one milk quality payment class.     

Investigation of risk factors for clinical mastitis in British dairy herds with bulk milk somatic cell counts less than 150,000 cells/ml

A sample of dairy farms in Great Britain with a monthly bulk milk somatic cell count of less than 150,000 cells/ml was enrolled into a 12-month prospective study. At the end of the study, a questionnaire on milking practice and other farm management practices was sent to the 482 farmers who had collected data on the occurrence of mastitis throughout the 12 months. The response rate was 93 per cent. The reported mean incidence of clinical mastitis was 36.9 cases per 100 cow-years. Factors associated with an increase in the incidence of clinical mastitis were cleaning out the straw yard less frequently than every six weeks, more than 5 per cent of cows leaking milk outside the parlour, checking the foremilk, wearing gloves during milking, an average annual milk yield of more than 7000 litres per cow, dipping or spraying teats before milking and keeping milk with a high somatic cell count out of the bulk tank. Factors associated with a decrease in the incidence of clinical mastitis were using a cloth to dry the teats after washing them as part of premilking preparation, using calving boxes for less than 40 per cent of calvings, and using both cubicles and straw yards to house dry cows, as opposed to other housing.     

Nutrition and udder health in dairy cows: a review

Mastitis is still one of the three main diseases that affects the profitability of dairy farmers. Despite the implementation of the five-point mastitis control programme in the early 1970 s, the incidence in the UK has not reduced dramatically over the past 10 years. A review of the scientific literature indicates that there is a link between nutrition and mastitis in the dairy cow. The major impact of nutrition on udder health is via suppression of the immune system. Cows in negative energy balance are at a higher risk of ketosis and clinical ketosis is associated with a two-fold increase in the risk of clinical mastitis. Trace minerals and vitamins that can affect udder health are selenium and vitamin E, copper, zinc, and vitamin A and β-carotene.     

Preliminary studies on the prevalence of Mycoplasma bovis mastitis in dairy in cattle in Australia

A highly sensitive and specific PCR (MB-PCR) was used in preliminary studies to detect M. bovis in milk samples to investigate its association with high somatic cell count (SCC), an indicator of subclinical mastitis and one of the factors in down grading the quality of milk. A total of 186 and 167 herds were tested with 43% and 62% of herds positive for M. bovis in Victoria and North Queensland, respectively. The quarter milks from 52 cows with persistently high SCC were tested by MB-PCR and culture to investigate the association of M. bovis with major mastitis pathogens (MMP). M. Bovis was detected in 77% of cows of which 19% alone had M. bovis without any other bacteria, 17% had M. bovis in combination with major mastitis pathogens and 40% had M. bovis in combination with non-major mastitis pathogens. We believe that M. bovis is widespread in dairy cattle and has the potential to produce disease alone or to predispose the udder to disease caused by major mastitis and environmental pathogens. These studies have revealed a hitherto unrecognised high prevalence of M. bovis in dairy cattle in North Queensland and Victoria in Australia. These initial studies also give a clear association between M. bovis and elevated somatic cell counts.     

The epidemiology of Staphylococcus aureus infections from subclinical mastitis in dairy cows during a control programme

The objective was to investigate the spread of S. aureus in seven dairy herds. Milk samples were taken to determine mastitis pathogens and somatic cell count. An approved hygiene programme was established to control the spread of S. aureus from quarter to quarter. S. aureus isolates were differentiated by geno- and phenotyping to trace their spread within a herd.In two herds S. aureus showed a high prevalence, but were eliminated from the herds by the control programme. In these herds and a third herd typing results identified a particular type that was found much more frequently than all other types. The frequent types were repeatedly detectable during the study. In three other herds with a lower S. aureus prevalence and also in one herd with a long history of S. aureus and high prevalence subclinical mastitis was caused by several distinguishable S. aureus types. These types occurred simultaneously in the particular herd and showed little or no tendency to spread from quarter to quarter. They seemed to circumvent the control procedures resulting in a relatively high rate of new infected animals and therefore were hardly eliminated. The typing results and the clinical observations indicated that strains differed in their tendency to spread and their ability to infect udder quarters. In three herds typing methods identified a predominant type with the common epidemiological features of a contagious mastitis pathogen, while in the other herds the S. aureus type patterns were similar to that of environmental pathogens.     

Microbiologic investigation of an epizootic of mastitis caused by Serratia marcescens in a dairy herd.

An epizootic of subclinical and clinical mastitis caused by Serratia marcescens was investigated in a 1,000-cow dairy farm in California. Serratia marcescens was isolated from 13 to 18% of composite milk samples obtained from lactating dairy cows. During monthly milk sampling performed during a 4-month period, S marcescens was isolated from 38.8 to 62.3% of composite milk samples obtained from cows from which S marcescens was previously isolated. Few cows infected with S marcescens had evidence of clinical mastitis. Somatic cell count value was associated with isolation of S marcescens. Cows with somatic cell counts greater than 500,000 were 5.48 times as likely to have intramammary infections with S marcescens, compared with cows with somatic cell count less than or equal to 500,000. Lactation number also was associated with S marcescens intramammary infection. After adjusting for the effect of lactation number, cows with high somatic cell count values were 2.98 times as likely to have intramammary infection with S marcescens, compared with cows with low somatic cell counts. Infection with S marcescens was independent of days in lactation, production string, and daily milk production. Eleven months after the beginning of the epizootic, S marcescens was isolated from organic bedding samples obtained from the dairy. Despite numerous attempts, other sources of S marcescens could not be identified on this dairy.     

A descriptive epidemiological study of mastitis in 12 Irish dairy herds

: Factors relating to the occurrence of mastitis were studied on 12 Irish dairy herds with histories of elevated somatic cell count (SCC) and/or increased incidence of clinical mastitis cases. Milk recording data were analysed, housing conditions and calving areas were examined; dry cow therapy, clinical mastitis records, milking technique and aspects of milking machine function were assessed.Herds with a ratio of less than 110 cubicles per 100 cows were more likely to experience environmental mastitis. Herds with inadequate calving facilities, where cows spent prolonged periods on straw bedding, were likely to acquire environmental mastitis. In the majority of the herds, the selection of dry cow therapy lacked adequate planning. The majority of farmers took no action to reduce pain experienced by cows suffering mastitis. Deficiencies in parlour hygiene were evident in all herds experiencing elevation in SCC.     

Study of clinical mastitis in British dairy herds with bulk milk somatic cell counts less than 150,000 cells/ml

A 12-month prospective study of clinical mastitis was conducted in 482 British dairy herds with a bulk milk somatic cell count (BMSCC) of less than 150,000 cells/ml. The mean proportion of cows in the herd with clinical mastitis was 23.1 per cent (range 0 to 80), with a mean of 1.50 quarter cases per cow. The mean incidence rate of clinical mastitis was 36.7 quarter cases per 100 cow years (range 0 to 208.2). Twelve per cent of the quarter cases showed systemic signs, including inappetence and severe lethargy. Over 22 per cent of quarter cases occurred in the first seven days of lactation and over 50 per cent occurred in the first 90 days of lactation. Cluster analysis indicated that the main difference between herds with a low and average incidence of mastitis was the proportion of clinical cases occurring in the first seven days of lactation, 14 per cent compared with 44 per cent, respectively. The risk of severe clinical mastitis compared with mild clinical mastitis decreased significantly as the individual cow somatic cell count (SCC) in the month before clinical mastitis was diagnosed increased.     

Efficacy of two antibiotic treatments in curing clinical and subclinical mastitis in lactating dairy cows

AIM: To compare the bacteriological and clinical cure rates for clinical and subclinical mastitis in New Zealand dairy cows following treatment with either an intramammary penicillin-dihydrosptreptomycin preparation or a subcutaneous injection of penethamate hydriodide. METHODS: Milk samples were collected from clinical and subclinical cases of mastitis before and 14 and 21 days after initiation of treatment for bacteriological culture, somatic cell count determination and conductivity testing. RESULTS: No significant differences in the bacteriological cure rate of major Gram-positive pathogens, clinical cure rate, somatic cell count or conductivity were found between treatments. However, the bacteriological cure rate of coagulase-negative staphylococcus infections and the overall bacteriological cure rate was lower for quarters treated with penethamate than with penicillin-dihydrosptreptomycin. CONCLUSIONS: The bacteriological cure rate of mastitis caused by major Gram-positive pathogens, the clinical cure rate, somatic cell count and conductivity did not differ between the two antibiotic treatments. .     

Environmental and managerial determinants of somatic cell counts and clinical mastitis incidence in Ohio dairy herds

A stratified-random sample of 48 Ohio dairy herds participated in a 1-year disease monitoring survey to study herd management and environmental conditions affecting udder infection and clinical mastitis incidence. The mean monthly bulk-tank somatic cell count was used as an indicator of overall udder infection. Clinical incidence was determined by monthly on-farm interviews with the dairy producers. Management and environmental conditions were assessed by direct observation as well as by personal interview of dairy managers. The final multivariable analysis-of-variance model of log bulk-tank somatic cell count had an R² value of 0.43. Lower log bulk-tank somatic cell count was found in herds with hired milkers, a clean and dry cow exercise area, clean teats following milking and fewer milking cows. The number of months spent on pasture was also significant. The final model for clinical mastitis incidence had an R² value of 0.38. Less clinical mastitis was found on farms where straw bedding was used, pre-dip was not used, where there were fewer cows, fewer person-hours per cow were spent milking cows, a greater percentage of calvings occurred in the designated calving facility, and cows spent fewer months per year on pasture. Other potentially important disease determinants could not be included in the final models because of limited sample size relative to the model degrees of freedom (six each).     

The potential use of cell count linear scores in veterinary herd health and production control on dairy farms. A preliminary report

Subclinical mastitis is a major problem in udder health control. Reduction of this infection is hard to achieve because subclinical mastitis is not obvious to the farmer. This study examined the value to the farmer of regularly supplying somatic cell counts from individual cows for the control of subclinical mastitis. The use of linear scores, i.e. logarithmic transformations of cell counts, appeared to be appropriate when combined with other relevant information on udder health and included in a herd health computer programme.     

A diagnostic approach to educating Minnesota dairy farmers in the prevention and control of bovine mastitis

Six characteristics of innovations described as influencing their rates of adoption by farmers are their relative advantage, complexity, ability to be tried, visibility of outcome personal contact between the advocate and the farmer, and compatibility with existing values. In this study, these are related to the adoption of mastitis prevention and control procedures.An educational diagnostic method described by Green et al. was adapted from human health education and applied to mastitis prevention and control with a group of farmers form nine Minnesota dairy farms. The method included six phases. A social diagnosis determined farmers' perceived rewards from dairying to be profit-making, enjoyment of working with animals, a desire to see cows achieve their production potential and a desire to raise a family in a farm setting. An epidemiological diagnosis from the literature determined the reduction of new infection rate and increase in the infection elimination rate to be the principal means of reducing mastitis prevalence. Teat dipping, dry period therapy, detection of clinical mastitis, segregating infected cows at milking, correct udder preparation and correct function and use of the milking machine were the main behavioral factors involved in mastitis control. An educational diagnosis identified pre-disposing, enabling and reinforcing factors associated with mastitis control. Their use in a mastitis control education program is illustrated using the teat dipping behavior as an example. Planning implementation was the fifth phase of the method. It involved rating the importance to mastitis control of various possible control behaviors and the likelihood of changing them. A priority order for employing resources was established from these. Planning also involved defining the behavior changes desired of farmers in mastitis control. The final phase was evaluation.Information from a survey of 222 Minnesota dairy farms was also incorporated in the process. The diagnostic method proved valuable in helping the educators view mastitis from the farmers point of view. A practical educational program was produced.