A HACCP-based approach to mastitis control in dairy herds. Part 1: Development

Hazard Analysis and Critical Control Points (HACCP) systems are a risk based preventive approach developed to increase levels of food safety assurance. This is part 1 of a pilot study on the development, implementation and evaluation of a HACCP-based approach for the control of good udder health in dairy cows. The paper describes the use of a novel approach based on a deconstruction of the infectious process in mastitis to identify Critical Control Points (CCPs) and develop a HACCP-based system to prevent and control mastitis in dairy herds. The approach involved the creation of an Infectious Process Flow Diagram, which was then cross-referenced to two production process flow diagrams of the milking process and cow management cycle. The HACCP plan developed, may be suitable for customisation and implementation on dairy farms. This is a logical, systematic approach to the development of a mastitis control programme that could be used as a template for the development of control programmes for other infectious diseases in the dairy herd.     

DHI报告解读及应用

近年来,随着奶牛养殖业的迅速发展,DHI技术在奶牛场中的应用已经普及,依据DHI报告,可以了解牛场的饲养管理、繁殖配种、乳房保健及疾病防治等状况,进行科学的饲养管理及选种选配,有效地防治乳腺炎,合理地淘汰牛只,进而显著提高奶牛生产性能和经济效益。全面、准确解读DHI报告,在解决奶牛场的实际问题和牛群改良中,起着越来越重要的作用。主要以宁夏某奶牛场2016年2月的DHI报告为例,就DHI报告中的关键指标作一介绍,旨在使DHI报告在实际生产中发挥重要指导作用。     

Imbedding HACCP principles in dairy herd health and production management: case report on calf rearing

Driven by consumer demands, European legislation has suggested the use of HACCP (Hazard Analysis Critical Control Point) as the quality risk management programme for the whole dairy chain. Until now, an exception has been made for primary producers, but as regulations evolve, on-farm HACCP-like programmes should be ready to assure food safety as well as animal health and animal welfare. In our field experiment, the HACCP-concept was used to combine both optimal farm management and formalisation of quality assurance in an on-farm situation in the Netherlands. The process of young stock rearing was chosen, since its importance for the future of the farm is often underestimated. Hazards and their associated risk factors can be controlled within the farm-specific standards and tolerances, as targets can be controlled by corrective measures and by implementation of farm-specific worksheets. The veterinarian is pivotal for the facility-based HACCP team, since he/she has knowledge about on-farm risk assessment and relations between clinical pathology, feed and farm management. The HACCP concept in combination with veterinary herd health and production management programmes offers a promising approach to optimise on-farm production processes (i.e., young stock rearing) in addition to a structural approach for quality risk management on dairy farms.     

Application of HACCP principles to control visitor health threats on dairy farms open to the general public

An increasing number of Dutch dairy farmers have diversified their activities, often opening their farm up to visitors (tourist accommodation, farm shop, contact with livestock, etc). It is essential to prevent these visitors from having accidents or becoming ill, which could result in financial claims and might harm the reputation of the agricultural sector. This article describes how the hazard analysis critical control points concept and principles (HACCP) can be applied to these activities and integrated with on-farm operational herd health and production management programmes.     

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.     

The effect of becoming BVDV-free on fertility and udder health in Dutch dairy herds

The aim of the study was to investigate the effect of BVDV-free certification of dairy herds on fertility and udder health. Cases were defined as dairy herds that had at least one BVDV-antigen positive animal, subsequently gained the BVDV-free status by participating in the BVDV-control programme of the Animal Health Service (AHS) and maintained this status for at least 2 years. Controls had an unknown status for BVDV and two controls were matched to one case by region and herd size. Data concerning fertility and milk production of all herds were provided by The Dutch Royal Cattle Syndicate (NRS). After validation, data of 79,607 cows of 392 case herds and 124,831 cows of 730 control herds were analysed on ten fertility and three udder health parameters. For the analyses all observations were aggregated at herd level. To account for the matching, differences for fertility parameters were calculated between each of the two pairs of case-control within a matching code. The analyses were performed with these differences as dependent variables. Mixed models and GEE models were used for the statistical analyses of fertility and udder health. Case herds had a significantly lower abortion rate in the BVDV-free period than controls herds (10.3% versus 11.6%, P<0.01) while there was no significant difference for the other fertility parameters. There was no effect on mastitis prevalence or bulk-milk SCC but the mastitis incidence significantly decreased for case herds in the BVDV-free period (cases 0.6 % lower than controls, P<0.05). In our study the effect of getting the BVDV-free status may have been underestimated for several reasons like an unknown status for control herds, not knowing when an acute infection occurred in case herds and not knowing the management for both cases and controls. Interestingly, both significant variables, being abortions and mastitis incidence, are parameters that are more difficult to influence by the farmer than the other parameters (e.g. calving interval).     

Database system for herd health management of dairy herds especially for udder health

Integrated herd health management is an effective method to improve animal health as mastitis and fertility disorders in dairy herds. For optimizing the costs and work load for the herd health management, it is necessary to have a data tool that enables a quick and comfortable data handling and provides practicable handouts for extension. The Research Institute of Organic Agriculture in Switzerland (FiBL) has developed such a database-system for the animal health management project "pro-Q". Objective of this database is to combine external available and on-farm collected data and to provide routine tools on herd and cow level (incl. udder quarter level) for farmers, veterinarians and advisers. These tools should give a comprehensive overview over the animal health situation of the herd and the single animal level. Furthermore, the database presented in this article, meets the requirements of a multi-user system with remote-access which enables different instances to gain the requested information.     

A HACCP-based approach to mastitis control in dairy herds. Part 2: Implementation and evaluation

Part 1 of the study described the development of a Hazard Analysis and Critical Control Point (HACCP) based programme and accompanying handbook for the control of mastitis. This paper describes the implementation and evaluation of customised HACCP-based programmes, which were developed from the handbook and assessed on six Irish dairy farms. Both quantitative and qualitative (action research) research methodologies were used to measure the success of implementation and efficacy of control of sub-clinical mastitis as measured by Somatic Cell Counts (SCC) and the degree of compliance by farmers in adopting and maintaining recommendations throughout the course of the study period. No overall differences in SCC before and during the implementation of the study were found when all six farms were considered together. Three of the six study farms experienced a significant decrease in herd milk recorded SCC during the implementation of the control programme. An essential part of the study was achieving initial agreement on recommendations as well as ongoing monitoring of compliance during the study. This pilot study shows that HACCP can be implemented on farms as a means of working towards the control of mastitis and that farmer attitude, and understanding of mastitis are crucial in terms of motivation irrespective of practical approaches used to manage mastitis.     

Developments in veterinary herd health programmes on dairy farms: a review.

This review article addresses some major developments in herd health programmes for dairy farms over the last decades. It focuses particularly on herd health and production management programmes that use protocols and monitoring activities. The article further emphasizes the need for merging herd health programmes with quantitative epidemiological principles and methods. Subsequently, this article points to the latest developments regarding quality assurance in the dairy sector and some quality management methods. Quality should be regarded in its broadest sense. The importance of integrating veterinary herd health programmes and quality (risk) management support at a dairy farm level is stressed. Examples are provided.     

Physical examination and palpation findings of mammary glands and indications of udder health in goat milk]

In dairy goats there is less evidence for relationships between udder form traits, results of physical udder examinations and mastitis indicators in the milk than in dairy cows. In 413 goats (predominantly Weisse Deutsche Edelziege and Bunte Deutsche Edelziege) from five herds (free from C.A.E.) repeated investigations of 2537 udder halves and fore milk samples were carried out in order to compare udder traits with findings in the milk. Less than 20% positive bacteriological findings and a low incidence of clinical mastitis testified a good clinical udder health status of the herds. Small teat-floor distances, loose hanging of the udders and bottle-shaped teats, findings which tended to become more frequent as lactation and lactation numbers progressed, indurative alterations of the mammary tissues and the teats tended to be connected with higher milk cell counts (> 1 million/microliter), more polymorphonuclear milk cells (> 40%), higher electrical milk conductivity (> 6.8 mS/cm) and lower milk lactose content (< 4.6%). A similar effect had a bad state of foot trimming. It is proposed to include the studied udder traits into herd health programs and breeding schemes for goats.     

Epidemiological Analyses of the Associations between bovine udder health and milking machine and milking management

This paper presents data from 158 dairy herds in northern Norway. The influence of the milking machine and milking management on the prevalence of subclinical mastitis and herd cell counts was calculated from a least squares model by a backward elimination procedure. It was shown that 16–45% of the herd udder health variation found at the start of the programme could be associated with milking machine and milking management variables. The following variables were found to be of significance: number of clusters in the herd, vaccum, function and vaccum regulator, undulation of pipeline, limping of pulsator, rate of pulsator, type of claw-piece, hygienic/-technical condition of liner, preparation time, air admission during application of teat cups, overmilking and machine-on time.     

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.     

Mastitis in Post-Partum Dairy Cows

Transition from the dry period to lactation is a high risk period for the modern dairy cow. The biggest challenge at that time is mastitis. Environmental bacteria are the most problematic pathogens around parturition. Coliforms are able to cause severe infections in multiparous cows, and heifers are likely to be infected with coagulase-negative staphylococci. During the periparturient period, hormonal and other factors make the dairy cows more or less immunocompromised. A successful mastitis control programme is focused on the management of dry and calving cows and heifers. Clean and comfortable environment, proper feeding and adequate supplementation of the diet with vitamins and trace elements are essential for maintaining good udder health. Strategies which would enhance closure of the teat canal in the beginning of the dry period and would protect teat end from bacteria until the keratin plug has formed decrease the risk for mastitis after calving. Dry cow therapy has been used with considerable success. Yet, a selective approach could be recommended rather than blanket therapy. Non-antibiotic approaches can be useful tools to prevent new infections during the dry period, in herds where the risk for environmental mastitis is high. Vaccination has been suggested as a means to support the immune defence of the dairy cow around parturition. In some countries, implementation of Escherichia coli core antigen vaccine has reduced the incidence of severe coliform mastitis after calving.     

Prevalence of subclinical mastitis and isolated udder pathogens in dairy cows in Southern Vietnam

Dairy production is not traditional in Vietnam. The farmers have little practical knowledge and udder health control is generally lacking. In order to give the farmers appropriate advice, knowledge about the distribution of udder pathogens is crucial. The aim of the study was to investigate the prevalence of sub-clinical mastitis and to identify udder pathogens isolated from smallholder dairy herds in Southern Vietnam. Twenty farms with a herd somatic cell count (SCC) ranging from low (≤400?×?10³?cells/mL) to high (>400?×?10³?cells/mL) were randomly selected. Milk samples were collected from 458 quarters of 115 clinically healthy cows. SCC was analyzed on farm by a portable cell counter. Bacteriological samples were taken using Mastistrip^© cassettes and sent to Sweden for examination. For all herds the mean herd SCC was 632?×?10³/mL milk. The prevalence of subclinical mastitis at quarter SCC basis was 63.2 % and at cow basis 88.6 %. Only 40 % of all cows were bacteriologically negative in all quarters. Streptococcus agalactiae was the most commonly found bacteria species, isolated from 96 of the 458 quarter samples, in 13 of the 20 farms. The results indicate pronounced subclinical mastitis problems among the dairy cows in this region mainly due to infections with S. agalactiae. The high prevalence of this highly contagious pathogen is probably attributable to the generally poor milking hygiene and low awareness of proper measures to prevent occurrence and spread of udder infections. A strict, targeted action program for the herds in this area is required in order to lower the prevalence of subclinical mastitis.     

An epidemiologic study of disease in 32 registered Holstein dairy herds in British Columbia.

Data recorded in a herd health management system were obtained from 32 registered Holstein dairy herds from British Columbia. Frequencies of disease were described, and the effect of herd, age, year, season, and the interrelationships between diseases within a lactation on the occurrence of disease were evaluated. Lactational incidence rates were computed for diseases with a short period of risk (ie, udder edema, milk fever, retained placenta, metritis, displaced abomasum, and ketosis), whereas for diseases with a longer period of risk (ie, cystic ovaries, mastitis and stable footrot), incidence densities were calculated. Overall, the disease incidence was low and showed an increase in frequency by year, which we attributed to more observing and complete recording by the owner, rather than an actual increase in disease incidence. Most diseases occurred early in lactation and their frequency increased with lactation number; the exception was udder edema, which occurred mainly during the first 2 lactations. An informal path model of disease interrelationships was made conditional on herd. Based on the results we inferred 2 independent pathways: one started by udder edema, and the other by milk fever. Udder edema was directly associated with mastitis occurrence from 0 to 30 d in lactation, metritis, and cystic ovaries. Mastitis from 0-30 d in lactation increased the risk of both mastitis from 31-150 d in lactation and cystic ovaries. Both of these increased the risk of late lactation mastitis. Milk fever was directly related with displaced abomasum, which increased the risk of footrot. In general, diseases that occurred in early lactation tended to increase the risk of other diseases later in lactation.     

Risk factors for bovine mastitis in the Central Province of Sri Lanka

A study of the risk factors associated with mastitis in Sri Lankan dairy cattle was conducted to inform risk reduction activities to improve the quality and quantity of milk production and dairy farmer income. A cross-sectional survey of randomly selected dairy farms was undertaken to investigate 12 cow and 39 herd level and management risk factors in the Central Province. The farm level prevalence of mastitis (clinical and subclinical) was 48 %, similar to what has been found elsewhere in South and Southeast Asia. Five cow level variables, three herd level variables, and eight management variables remained significant (p?相似文献   

Enhanced Erythrocytic Lipid Peroxides and Reduced Plasma Ascorbic Acid,and Alteration in Blood Trace Elements Level in Dairy Cows with Mastitis

Oxidative stress has been associated in several inflammatory conditions and incriminated in the pathogenesis of many diseases. However, little information is available on the status of plasma antioxidant levels, essential components of important antioxidant enzymes such as copper, zinc and selenium in blood, and the end product of oxidative damage to the erythrocytic polyunsaturated fatty acids in inflammatory udder conditions. Blood samples were collected from three groups of dairy cows, with 21 in each group: animals with healthy udder, clinical mastitis, and subclinical mastitis. These animals were randomly selected from a herd on the basis of the California mastitis test, somatic cell count and total bacterial count. The mean plasma ascorbic acid concentration was significantly lower in cows with subclinical (p = 0.004) and clinical mastitis (p = 0.000) and the erythrocytic lipid peroxide levels were significantly (p = 0.000) higher in clinical mastitis as compared to controls. There was a significant decrease in mean blood zinc concentration in subclinical (p = 0.005) and clinical mastitis (p = 0.000), but an increase in mean blood copper level in the clinical mastitis group. It was concluded that the blood antioxidant status declines in inflammatory udder conditions, suggesting that incorporation of antioxidants may help in better management of mastitis in dairy cows.     

Prevalence and antibiotic resistance of mastitis pathogens isolated from dairy herds transitioning to organic management

Changes in udder health and antibiotic resistance of mastitis pathogens isolated from dairies upon conversion from conventional to organic management over a 3-year period was studied. Coagulase-negative staphylococci (CNS) were the most prevalent mastitis pathogens isolated. CNS were significantly less resistant to β-lactam antibiotics when isolated from milk after the herd transitioned to organic management. Cessation of the use of antimicrobial therapies in dairies in combination with organic management could lead to a reduction in the antimicrobial resistance of mastitis pathogens.     

Is there a role for organic trace element supplements in transition cow health?

Optimal transition cow health is the key to success of the subsequent lactation, and increasing attention has been focused on management and nutritional practices that support it. Physiological stress during the transition period alters the efficiency of the immune system, making the lactating dairy cow more susceptible to infectious diseases, such as mastitis and metritis, with subsequent impairment of reproductive performance. Trace elements have a specific role in free radical control at the cellular level and influence the anti-oxidant/free radical balance. Dietary trace elements must be available for absorption throughout the whole of the digestive process until they reach the final site of absorption in the small intestine. Negative interactions between minerals can occur and, as the intestinal environment lowers the absorption of ionic minerals, chelation technology has been developed to increase mineral bioavailability. Organic trace elements have been used in dairy cow experiments, resulting in significant improvements in udder health, lameness and reproductive performance.     

Effects of a two-year dairy herd health management programme on udder health, use of antibiotics and longevity

Since 2003, the Research Institute of Organic Agriculture (FiBL) is realizing a herd health management programme ("pro-Q" project) focussing on udder health. The objectives of the project are: (1) to reduce antibiotic mastitis treatments, (2) to optimise udder health and (3) to improve longevity, measured as averaged number of herd lactations. The farms get expert advice in prevention and treatment on herd- and animal-level. After 2 years, treatment recordings of the 65 investigated farms showed that antibiotic mastitis therapies were reduced from 38 to 26 treatments per 100 cows and year (equals a reduction of 32%). Lactation numbers of the herds increased significantly by 0.2 lactations from 3.3 to 3.5 lactations per cow. Udder health remained constant over all farms during 2 years: theoretical bulk milk cell counts averaged constantly at around 180000 cells/ml. Improvement of udder health on farm level was significantly influenced by higher somatic cell count when the project started and enhanced by farmer's motivation and farm-veterinarians' commitment to the project.