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Looking to the future at BCVA

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01 January 2016, at 12:00am

Richard Gard reports from the 2015 congress of the British Cattle Veterinary Association, at which the long- term management of cattle practice was addressed by a number of speakers.

THE future-proo ng of cattle veterinary practice was one of the major themes covered at last year’s British Cattle Veterinary Association congress, and this was expressed by the president, Gareth Hateley, in his opening address.

There is concern about the next few months with dairying and the long-term management of effective practice. The first speaker, Joep Driessen (Cow Signals), indicated clearly that there was much more veterinary surgeons could be involved in that will reduce feelings of farmer insecurity.

The speaker covered a great deal of points very rapidly and in order to assimilate his observations in full it is necessary to purchase copies of the Cow Signals books. Essentially the approach is to consider feed, water, air, light and space and to double the lifetime of the cow.

A stress-free calving line for three weeks before and three weeks after calving is important, with the cow having “plenty of space” in the last days before calving.

Technology is available to the farmer to offer a greater feeling of control including coughing calves identi ed two weeks before the ear of the farmer, cameras to show an empty rumen, measuring eye depth, recording the colour of urine and detecting dull skin.

Automatic sensor technology is available and affordable. A cattle vet should be achieving 80% prevention/ consultancy and 20% treatment. Farmers listen to other farmers more than they listen to vets and the challenge is for vets to be better educators.

Research funding

Details of the Ruminant Research Bursary, sponsored by MSD Animal Health, were outlined by Paul Williams. Project support of up to £4,000 is available to veterinary surgeons for topics “of practical interest to vets in practice”.

Data analysis and statistical support are available and applications are reviewed by Bristol University. For 2016 the projects will be targeted at cattle youngstock. Two bursaries are awarded each year and applications were due by 31st December.

Findings from research projects provided insights into forthcoming developments. Georgios Oikonomov (University of Liverpool) outlined the use of next generation gene sequencing for mastitis pathogens. This technology is expected to become very much cheaper and available over the next three years.

Initial trials have shown that detecting bacterial DNA has identified anaerobic bacteria in clinical samples (e.g. Sneathia sanguinegens) and organisms that are difficult to isolate by culture, including Listeria innocua and Rhodococcus spp. The work raises the possibility of routinely detecting previously unrecognised pathogens.

Cost of control

Peter Down (University of Nottingham) has measured the cost-effectiveness of mastitis control interventions to reduce intramammary infections acquired during lactation.

A probabilistic decision model is to be made available through the current mastitis control plan that will assist clinical decision-making. The cost-effectiveness of ventilation improvements, feed space, pre-milking teat dipping, y control and biosecurity were specific areas addressed.

The clinical presentation and incidence of ischaemic teat necrosis was discussed by Roger Blowey (Gloucester). The disease is mostly seen in first lactation heifers, starting with an erosive lesion at the teat/udder junction and then progressing down the teat. The condition is intensely irritant with the whole teat often being licked off.

Two herds are recorded with a 20% loss of heifers. Treponemes were isolated from 11 of 12 tissue samples and 19/22 cotton wool swabs. A show of hands indicated that the condition has been widely observed in practice.

E. coli isolates 

Andrea Turner (University of Bristol) has an ongoing project to identify the prevalence of extended spectrum B-lactamase-producing E. coli and antimicrobial resistance of E. coli isolates from dairy herd faecal samples.

The antimicrobial use history on-farm is recorded and reviewed according to the resistance patterns detected. Approximately 200 samples have been analysed to date from seven herds with from 0 to 2.7% ESBL isolates.

Early lactation foot-trimming of dairy heifers has been evaluated by Oli Maxwell (University of Nottingham) in a randomised controlled trial. A surprising level of heifer sole bruising was an initial finding. Sole ulcer was recorded in 16% of the heifers and a further 16% were lame from other conditions.

Hoof trimming at 50 to 80 days post-calving did not show a milk yield increase for the heifer groups but individual animals benefitted from being trimmed. Lame heifers that were left untrimmed were at risk from subsequent culling.

Medicines

Three speakers contributed to the difficult topic of the responsible use of medicines. Prof. David Barrett (University of Bristol) provided a medicine use overview.

The indications are that veterinary surgeons need to be particularly careful when prescribing medicines that do not have a species-specified withdrawal period, with compulsory withdrawal periods then applying of seven days for milk and 28 days for meat. It is now specifically prohibited to advertise antimicrobial medicines to farmers and other animal keepers.

There is a lack of information about the exact use of medicines on-farm. The collection of data, for product use in multiple species, does not indicate the volumes administered to cattle or sheep. Animal dose levels are often underestimated for heavier animals (over 500kg) and overestimated for lighter animals (below 150kg). Under- dosing is a concern for potential development of resistance.

The thrust is that the profession should avoid using veterinary medicines, especially antibiotics, to facilitate the use of suboptimal husbandry methods unless such use may be unavoidable to safeguard animal welfare.

Vaccine use in most instances is preferable to use of medication and is to be encouraged. Veterinary and other bodies are offering an increasing depth of information and support. The pressure will increase for a change in prescribing and recording whether the science supports animal resistance transfer to humans or not.

David Tisdale (Langford Farm Animal Practice) described how the practice has achieved an 87% reduction in the prescribing of third and fourth generation cephalosporins, uoroquinolones and macrolides. Engagement from the farmers has been very encouraging. An overall increase in volume (mg of antimicrobial) of 5% took place since 2010 with a 10% increase in dairy cow numbers.

The move to the first line treatments and away from the products of concern has not resulted in a decline in herd health or clinical cure rates. Providing a medicines audit and expressing antimicrobial use in terms of doses, courses and economics has been useful to the farmers.

First line treatments often have a higher dose volume per animal and a reduction in the number of courses per animal is believed to be related to training for clients, with emphasis on accurate dosing and course completion.

Dry cow therapy

Peter Edmundson (UdderWise Ltd) presented a realistic assessment of selective dry cow therapy where cows receive teat sealant instead of antibiotic at drying off. The full paper is within the congress proceedings.

The speaker identified understandable concerns for the farmer in moving away from dry cow therapy for all cows. These include the need for help from veterinary surgeons to manage the change, concerns about increases in cell count, clinical mastitis, dead cows or culling.

For the vet there will be issues over herds with no individual cow cell count data or mastitis records and charging an economic rate for the veterinary time to sort out management change.

Training for the hygienic administration of teat sealant is essential. Selective dry cow therapy should be considered for herds with cell counts below 200,000 but for herds with higher or rising cell counts the vet should work with the farmer first to reduce the cell count. All cows that have been treated during the lactation should receive antibiotic at drying off. Peter concludes that the pressure, from milk buyers, for the farmer to consider selective dry cow therapy should be viewed as an opportunity for veterinary practices to become more involved with mastitis control on-farm.