British mastitis conference 2019

The 31st British Mastitis Conference was held on 6 November 2019, with a workshop on mastitis data management and control, with emphasis on cow housing on the preceding day. The organisers report that there continues to be a number of non-UK based delegates attending, including the presentation of Knowledge Transfer posters. The conference could not be held without the continuing support of sponsors, with Vétoquinol again offering Platinum sponsorship. The conference is aimed particularly at veterinarians, farm consultants, research scientists, students and academics, in fact at anyone with an interest in dairy farming and mastitis. The organising and scientific committee bring together a mix of researchers and practitioners from both the UK and further afield, and for the 2019 conference speakers were invited from Belgium as well as the UK, with Knowledge Transfer papers presented from India and the UK, many as collaborations with researchers from further afield.

The first speaker was Colin Mason, Veterinary Surgeon, SRUC Veterinary Services, Dumfries, UK who discussed whether Mycoplasma bovis is an important mastitis vector. Colin advised that Mycoplasma bovis was first recognised as a bovine pathogen in the UK over 40 years ago, being one of 13 Mycoplasma species known to infect cattle. Mycoplasma bovis is considered more pathogenic than many other species and is considered to be the most important mycoplasma mastitis pathogen. But it is also known to cause a complex of disease syndromes besides mastitis, including pneumonia, arthritis, keratoconjunctivitis and otitis media. Mycoplasma species have no cell wall and instead have a cell membrane with variable surface lipoproteins. These are used for organism attachment and elicit variable immune responses from the host. The organism can also produce and survive in biofilms and it is this plus variable evasion of the host’s immune response which permits the organism to persist and cause disease. The experience in the UK has been with sporadic cases occurring. However, there have been some notable exceptions with outbreaks of disease being seen in conjunction with arthritis and pneumonia and such incidents involving larger numbers of cattle. One common clinical sign is that Mycoplasma bovis mastitis cases do not respond well to treatment. For the future, Colin suggested that assessing herd level disease status and maximising animal immunity provide a potential way forward in reducing the disease effects of

Mycoplasma bovis. He advised that group calving pens had recently been identified as potential risk factors for Mycoplasma bovis transmission but individual calving boxes together with basic biosecurity actions can help prevent spread. It is also essential that any waste milk from infected cows is not fed to calves.

The following speaker was Ian Ohnstad, The Dairy Group, Taunton, UK who highlighted the importance of milking time tests. Ian stated that International Standards exist which clearly set out the procedures and methods that should be used to test a milking machine (ISO 6690:2007) and outlines the basic operating parameters which should be achieved (ISO 5707:2007). However, these standards describe tests which are generally carried out with the milking system operating but not actually milking any animals. Ian stated that it had become increasingly apparent that evaluating a milking system without taking account of the animals being milked or of the operator that is using the machine is likely to lead to an in-complete evaluation and of more concern, may lead to a system being described as satisfactory when in fact this is far from the case. Ian highlighted a number of key points that will allow anybody with a working knowledge of cow behaviour and a basic understanding of the mechanics of machine milking to assess the suitability of the milking system. He emphasised that much could be carried out without expensive technical equipment, but by the use of good observation.

Four Knowledge Transfer posters were selected for oral presentation. Cristian Ps, University of Reading, UK, presented research on “Fast MALDI MS profiling for the analysis of cow milk to investigate clinical and pre-clinical mastitis.” Neelesh Sharma, Sher-e-Kashmir, University of Jammu, India presented a report of a “Study on heifer mastitis – prevalence, risk factors, aetiology and antibiogram in Jammu, North India”. Derek Armstrong, Agriculture and Horticulture Development Board, Dairy sector, summarized the results of “QuarterPRO – an industry initiative to promote and improve udder health”, and advised that it was now available to use across the dairy farm sector. The final Knowledge Transfer presentation was by Francisco Malcata, University of Glasgow, on a “Comparison of two point-of-care tests to support treatment decisions in non-severe bovine clinical mastitis”.

 

Sofie Piepers, MEXTM, Belgium discussed Dairying and mastitis control in arduous environmental conditions. Sofie´s paper focussed on the negative impact of heat stress and on how mastitis is controlled (or not controlled) in those countries that have to deal with often arduous environmental conditions. Sofie reiterated that mastitis is the result of micro-organisms, typically bacteria, entering the bovine mammary gland via the teat canal, establishing an intramammary infection (IMI) and resulting in an inflammatory reaction. She pointed out that mastitis was a multi-factorial issue but when the balance tilts in favour of the pathogen, mastitis occurs. In countries including the Middle East and Israel that struggle with often extremely hot weather conditions, the risk of mastitis is even greater, especially in the summer months, as the cows are constantly exposed to heat stress. Sofie advised that today´s dairy cattle are nowadays more susceptible to heat stress than those of the 1950s due to the increased milk production and feed intake. Heat stress now starts at a Temperature Humidity Index (THI) of 68 (previous studies indicated a THI of 71). High yielding cows are obviously more susceptible to heat stress than low yielding cows, as feed intake and milk production and thus the heat production results in a shift of the thermoneutral zone to lower temperature. However, an effective cooling system, high quality forages and an optimal standard mastitis prevention and control program are the key success factors for obtaining and maintaining good udder health throughout the year.

Jamie F Robertson, Livestock Management Systems Ltd, Aberdeen, looked in detail at the “Environmental management of dairy cows”. Jamie emphasised that most of the design features of a competent cattle building were established more than 30 years ago, based on empirical datasets and the presence of independently funded farm building design experts. He advised that the independent funding was no longer available in the UK, and the farm building sector had then progressed in a stilted manner, sometimes adopting designs from overseas which became a fashion but have no basis in objective design. Jamie pointed out that modern dairy cattle are the pinnacle of decades of genetic improvement, nutrition and agronomic support, and practical farming knowledge. They were in effect, the athletes of the modern dairy world, and are subjected to significant physiological demands. Jamie highlighted the fact that the backdrop to this modern dairy system is an apparently random collection of buildings, of various ages, materials and designs that can only serve to support or hinder production and health. The key requirements of a building for dairy cows are to prevent the accumulation of heat and moisture, to provide access to fresh air changeovers, and to protect from high wind speeds. He emphasised that environmental conditions that favour or restrict a bacterial/viral population outside the host will have a direct impact on the quantity/concentration/dose of viable organisms that remain in that environment. Besides the environment influencing dose rates of pathogens it also impacts on animal physiology, whereby conditions outside a range of ‘normal’ conditions may exert a physiological pressure that constitutes stress. Stress is a normal response, but the problem in our livestock systems occurs when the duration of stress is sufficient to create a significant, negative impact, such as energy deficit or depression of immune function. Jamie provided a detailed look into what makes a good cow environment and how the problems of most cattle buildings can be readily rectified, with immediate paybacks in animal health and farm profitability.

The final paper of the 2019 British Mastitis Conference was the now regular presentation of a practical mastitis case study. The emphasis this year was on “Reducing dry period infection rate and improving somatic cell count”, using the targeted approach provided by the UK AHDB Dairy Mastitis Control Plan. The dual presentation by James Breen, University of Nottingham and Evidence Group, Cumbria, UK and dairy farmer, Austin Russel from Gloucestershire, provided an insight into how the detailed analysis of the farm data identified that the herd mastitis ‘pattern’ was one of environmental infections of dry period origin, with lactating period origin infections more seasonal and associated with periods at pasture. A focus on dry cow management was prioritised through 2018 and 2019, and included a review of drying-off technique, availability of loafing and feed space, improving ventilation and assisting with advice around the client’s longer-term aspiration to move away from loose yards to housing dry cows in cubicles. Although the herd average somatic cell count (SCC) has remained similar, at just below 200,000 cells/ml over the two year period from autumn 2017 to 2019, there had been a dramatic improvement in control of dry period new infections. The dry period new infection rate had decreased from an average of 21.6% during summer 2017 to 11.4% for the three recordings to September 2019. Between the autumn of 2017 and that of 2019 the incidence rate of clinical mastitis was reported to have decreased from 64 cases per 100 cows/year for the 12 months ending September 2017 to 47 cases per 100 cows/year for the 12 months ending September 2019. Th rate at which cows were detected with a new case of clinical mastitis during the first 30 days of lactation reduced from 2 in 12 cows affected at the end of summer 2017 to 0.62 in 12 cows affected for the end of summer 2019. Both speakers highlighted that the implementation of this structured approach to mastitis control was continuing at the farm and provided a platform for future progress.

The 2020 British Mastitis Conference will be held on Wednesday 11 November 2020, with a workshop on the previous day. More information is available at www.britishmastitisconference.org.uk where all previous proceedings are available to download.