Cattle represent 25 per cent of the total livestock mass of the UK as estimated by population corrected unit, approximately equivalent to the pig and poultry sectors combined.
Antimicrobial use in the cattle industry therefore plays an important role in the UK’s overall use of antibiotics.
There is currently no comprehensive data set relating to antibiotic use in the dairy sector, however figures from sales data, a FarmVet survey, and other small subsets of information have been used to develop targets for the sector as work continues to develop are more robust, centralised system of collecting on-farm antibiotic usage data.
The British Cattle Veterinary Association’s Dr Elizabeth Berry, is a member of the RUMA Task Force for dairy and beef.
She says: “What is important is the data collected is useful and that it is collated in a way which can be used at vet and farm level to help farmers look behind the figures at where changes can be made.
“Most farmers are aware of their responsibilities regarding responsible use of antibiotics and are doing a good job. Red Tractor standards are helping drive this and recording data is becoming easier as technology improves.
“But all farmers will have to get on-board, not only to meet the voluntary targets by 2020 but also to meet the requirements of the milk buyers and retailers they supply.”
A large proportion of dairy farms are likely to be relatively low users of antibiotics. However, a study carried out by the University of Nottingham showed 25 per cent of antimicrobial users in the sector represented 52 per cent of the total quantity of antimicrobials used.
Identifying these high users and the reasons behind it are important for reducing total antimicrobial use.
The RUMA Task Force report has highlighted focus areas for antimicrobial use in the dairy sector as well as setting specific targets, with reducing HP-CIAs by 50 per cent by 2020 and monitoring intra-mammary tubes high on the agenda.
Focus areas for dairy
Antimicrobial use reduction through improved herd health management
By working with the farm vet to improve herd health management, reduce disease incidence and therefore avoid the need for treatment, antimicrobial usage can be significantly reduced.
Veterinary surgeon Dr James Breen, University of Nottingham, says: “In herds which experience an increased rate of new cases of clinical mastitis in cows less than 30 days in-milk, improving the management and hygiene of the dry cow environment is likely to result in a significant reduction in cases, as the rate at which infection is acquired prior to calving is reduced.
“Examination of clinical mastitis records and individual cow somatic cell count patterns allows specific areas of management and husbandry to be targeted and improved, reducing the number of animals requiring antibiotic treatment in the first place and improving welfare and productivity.
“As many cases of mastitis are caused by opportunistic environmental infection, some antibiotic treatment is unavoidable, but it is important to recognise there remains great scope to rationalise and modify existing treatment approaches to further reduce unnecessary antibiotic use.
“For example, injectable antibiotic treatments for mild and moderate cases of clinical mastitis can result in high antimicrobial use, despite being highly unlikely to improve the chance of cure.
“Selective dry cow therapy, rather than blanket treatment of all cows, not only reduces antibiotic use but is better for cow health as there is evidence to show treating an uninfected cow with antibiotics can have a negative effect because it impacts on the normal bacteria in the udder, upsetting the balance which can lead to greater risk of mastitis after calving.”
TOOLS TO MONITOR ANTIBIOTICS USE
Monitoring is an essential first step to reduce overall antimicrobial use (AMU).
The University of Nottingham had created a free AMU Calculator, available on the AHDB website, where farmers/veterinarians can input medicines used on-farm and assess their overall AMU.
The University of Nottingham AMU Benchmarking Tool is also available for groups of producers which wish to benchmark AMU across a group of farms using the AMU Calculator.
To find out more about both these tools, visit dairy.ahdb.org.uk.
The use of antibiotic footbaths can cause a huge spike in antibiotic use on dairy farms, even if they are not used frequently, according to a study carried out by the University of Nottingham.
Veterinary surgeon Robert Hyde, who authored the study, says: “Not only does it drastically increase antibiotic use but there is no good evidence to prove it is beneficial.
“Rather than using an antibiotic footbath, it is far better to take a preventative approach to lameness, such as improved hygiene and regular non-antibiotic footbathing, and a more targeted approach to treatment when necessary, such as by identifying lame cows at an early stage and treating individual cows topically with an antibiotic spray, rather than subjecting the whole herd to an antibiotic footbath.
“Another negative aspect to this is as these products are ‘off licence’ they automatically attract a statutory withdrawal period of seven days for milk and 28 days for meat, which really makes them unviable to legally use in dairy cattle.
Feeding waste milk to calves can be bad for them, bad for the herd’s health, and bad for human health, says veterinary surgeon Dave Gilbert, a director of Dairy Insight consultancy.
However, he believes the definition of what is regarded as waste milk can be blurred.
He says: “Normal whole transitional milk, which is produced immediately after calving and cannot be sold as it is classed as colostrum, is perfectly safe to feed to calves.
“This is completely different to milk from cows which are unwell and undergoing treatment as this will potentially contain pathogenic bacteria and antibiotics. Feeding low dose antibiotics to calves is not a good idea as it affects the healthy microflora in the rumen and impacts on the future rumen development of the animal.
“It also adds to the risk of antimicrobial resistance developing and circulating on-farm. This then impacts on being able to successfully treat some problems, for example, strains of E.coli which have become resistant to antibiotics.
“There is also the human health perspective of antimicrobial resistance which develops in animals or on-farm and is then passed to people.”