Case studies

Read antibiotic use case studies, showing how farmers and vets have implemented changes on-farm that have reduced, refined or replaced use of their antibiotics.

A persistent problem with watery mouth meant antibiotics were used as a preventative medicine in the past at David Raine’s Old Parks Farm near Penrith in Cumbria. Now, though, their use has all but been eliminated says Mr Raine, who runs 1,000 Swaledale, Mule and Bluefaced Leicester ewes as well as upland beef. “The key to this has been the quantity and quality of colostrum provided within one hour of the lamb’s birth,” he says. “To make sure there is sufficient quantity, we provide the ewe with good nutrition – plenty of energy, protein and trace elements from a home-produced ration including fodder beet,” he explains. Careful observation and diligence at lambing, monitoring ewe health and udder checks along with the use of colostrum substitutes where required, ensures that every lamb receives the colostrum it needs. All lambs are treated with iodine at birth. “If they stay housed, because of bad weather, they are navel dipped again. We have found this second dip has cut joint ill markedly. “We have virtually eliminated watery mouth and joint ill, cutting our antibiotic use to just about nil in the process,” Mr Raine adds. Even though the upland farm faces harsh weather, reducing the time that the flock is housed is key. “We are mainly outdoor lambing now with Swaledales making up three-quarters of the flock. They need minimum interference which cuts the need for any antibiotics at all.” Housing for the remainder of the flock is also minimised. “Early lambing mule ewes are brought close to the housing as lambing nears so we can keep an eye on them. Nutrition is raised to boost the ewe’s natural immunity to disease and to yield colostrum. “But they don’t come indoors until the last minute to cut the build-up of bacteria,” says Mr Raine. The farm has also introduced a week’s break in the lambing period to break the cycle of disease. The shed is cleaned out completely during this time before rebedding with plenty of straw. Beyond the lambing period, all replacement stock is vaccinated to give cover against clostridial disease and enzootic abortion. “Using a vaccine for enzootic abortion and stopping the use of preventative antibiotic treatment is a practical, and sensible thing we could all do,” says Mr Raine.
Farmed salmon is a key part of Scotland’s world-renowned food industry, accounting for around 40% by value of Scottish food exports and contributing £2bn annually to the UK economy. It represents a huge Scottish success story, an outstanding example of a ‘good food’, both in terms of its exceptional nutritional value and its standards of production. Formerly, salmon was a delicacy only a privileged few could enjoy. With the advent of fish farming, salmon and its nutritional benefits became available worldwide at more affordable prices. In the 1980s, both fresh- and sea-water salmon farming saw significant growth. Fish veterinarian Ronnie Soutar, formerly director of veterinary services at University of Edinburgh and now Head of Fish Health at Aqualife Services Ltd, explains that with the huge opportunities came some serious problems. The main issue back then was that thousands of farmed salmon became infected with Furunculosis, a bacterial fish disease carried by wild salmon. “There were no vaccines that worked well against Furunculosis, and there was concern whether it would be possible to produce one that was sufficiently effective,” explains Ronnie. “This led to fairly widescale use of antibiotics in the 80s to control the inevitable bacterial infection the fish would develop. At the time it was best practice – the best advice offered by Government specialists and fish vets to ensure fish welfare was maintained and the quality of the end product could be ensured.” However, the only way in which fish farmers could treat stock affected by Furunculosis was to mix antibiotics into fish feed and that is hard to get right. “It’s really difficult to ensure each fish receives the correct dose of antibiotic via medicated feed. Appetite varies between individuals, especially when they are suffering from a bacterial infection. Suboptimal dosing with antibiotics—in farming or for human medical treatment— can speed up the development of antibiotic resistance, which is when bacteria change and become resistant to the antibiotics used to treat infections they cause.” In the 1990s, concern was growing about the use of antibiotics – including the potential to impact the natural environments in which the fish were being reared. This is when the Scottish Salmon Producers Organisation collaborated with what was then the Government Scottish Office to work out a way to develop an effective vaccine against Furunculosis in farmed salmon. As well as protecting against the disease, it was imperative the vaccine would have no impact on the quality of the salmon product or any effect on humans. Dr John Webster, technical director at the Scottish Salmon Producers' Organisation, explains that the process of developing a vaccine took a number of years. In that time, not only did the vaccine have to be refined and developed to be commercial viable, but administration of the vaccine needed to be perfected. “Many people don’t think it’s possible to inject a fish, but it is,” he says. “The vaccine is injected into the abdomen of salmon during their fresh-water phase using an automated process. “Now, almost 20 years since the first vaccines were made commercially available, all Scottish salmon are vaccinated and we have virtually eliminated the use of antibiotics to treat Furunculosis. Controlling it in the farmed fish has also helped reduce the disease reservoir in wild fish.” Today, Scotland produces salmon with a farmgate value of around £650m annually. It is estimated that the industry indirectly supports around 8,000 jobs in Scotland, with a significant number of these in the remote northern and western regions where it operates. Furthermore, salmon producers are at the heart of their local areas, reporting a spend of £448 million on suppliers and services and capital investment of £63.1 million. However, John Webster says a single strategy is not enough – diseases and health challenges are constantly changing, and veterinary science needs to stay one step ahead. “Our challenge now is not so much the potential for bacterial infection in the salmon but sea lice. To overcome this, we are utilising lumpfish and wrasse which act as cleaner fish for the salmon, swimming alongside them and eating the parasites. However, the cleaner fish can get their own bacterial challenges so we are working on new vaccinations to ensure they can stay healthy and keep the salmon healthy in turn. “Overall we’re in good shape, having reduced sales of antibiotics into the fish sector from 1.7 tonnes of active ingredient in 2014, to less than one tonne in 2015. Can we go lower? We will try, but we must also strike that difficult balance with upholding animal welfare, which we’re committed to getting right.”
John Wood, who farms at Merley Hall Farm in Dorset, made the switch from antibiotics to vaccination after 100 ewes from the 2,000-head flock aborted three years ago and as a result has seen a drop in his antibiotics bill. “On the first day of lambing, we noticed one of the ewes had aborted, by day two we had another half-a-dozen and by day three we’d had about 25 abort. When the lab confirmed it was enzootic, the only advice we were given was to treat the whole flock with antibiotics,” explains Mr Wood. Enzootic abortion of ewes (EAE) is caused by the bacteria Chlamydia abortus and is responsible for 52% of sheep abortions in the UK. To treat flocks at the time of an outbreak, an injection with a long-acting oxytetracycline (Oxytet) is used on all sheep to reduce the risk of further abortion. Ideally, this should be used once tests confirm a  diagnosis, which is what happened in Mr Wood’s case, but many farmers tend to treat the whole flock before receiving results. In recent years, the rise in a “just-in-case” approach to administering antibiotics where no abortions have occurred has risen adding to the overuse of antibiotics in the sheep industry. Despite administering Oxytet to all of his flock, Mr Wood found about 100 ewes aborted by the end of lambing and he continued to see abortions the following year, although the number reduced. “The antibiotic seemed to slow it down, but once EAE is there you might not continue to jab the ewes, so for the two years after we spent about £2,000/year on oxytetracycline alone to prevent it from happening again.” As costs started to rack up, Mr Wood made enquiries about vaccinating and was surprised to find it was cheaper than he expected. With vaccinations ideally taking place four weeks prior to tupping, Mr Wood decided it was the right time to change. “You only have to vaccinate the ewes once in their lifetime, so it actually works out cheaper than using antibiotics. To vaccinate the whole flock it cost me the same amount as it did to jab the ewes for the two years after the abortion storm. If I hadn’t switched to vaccinating, I’d have spent double that by now administering precautionary antibiotics,” explains Mr Wood. You only have to vaccinate the ewes once in their lifetime, so it actually works out cheaper than using antibiotics. Since switching to the vaccination, he has had a successful year and has seen no abortions at lambing in February and March. Now, with ewes being both bought-in and replaced on farm, all will be vaccinated before they enter the flock by the end of the year. As part of its commitment to sharing best practice advice, AHDB Beef & Lamb has been working with industry organisations to ensure vets and farmers understand the importance of vaccinating to guard against abortion. Liz Genever, senior scientist at AHDB Beef & Lamb, says: “It is great to hear that John has made the switch to vaccination from antibiotics. It was a sound financial decision, both in terms of reducing vet and medical costs and reducing lamb losses.” “The removal of the oxytetracycline treatment from this flock will also reduce his antibiotics use by about six milligrams per production correction unit. We are still seeing about 10% of sheep farmers injecting ewes near lambing and some of these could easily move towards vaccination.” Fiona Lovatt, RCVS-recognised specialist in sheep health and production, says a practice that is still too common among sheep farmers is the use of whole-flock antibiotics treatment of ewes in late pregnancy to control enzootic abortion. As a routine practice, this is completely unacceptable, as there are effective vaccinations on the market. Vaccination is much better for the long-term health of the flock, because it reduces the number of affected ewes and reduces shedding of the chlamydia bug. In contrast, antibiotics treatment for routine abortion control is a short-term sticking-plaster approach that is a reflection of poor flock health management. Apart from being a much more responsible use of medicines, vaccinating instead of using antibiotics to control abortion is very cost-effective – an enzootic vaccine is only £2-£3 a ewe for a once-in-a-lifetime jab. Over the life of a ewe, this costs the same or less than repeated antibiotics treatments. Enzootic abortion is still the most commonly diagnosed cause of abortion and stillbirths in the UK. Despite this, we know that there are only about a million doses of enzootic vaccine sold each year, compared with the 3.5 million replacement ewes that enter the national flock. Ewes need to be vaccinated at least four weeks before they go to the ram, so now is the time to think about vaccination to effectively protect naïve ewes from picking up EAE next lambing time.    
Pneumonia is a disease of the lungs and is caused by interaction between the calf, its immunity, infectious bugs and the environment. “Cattle are particularly affected by pneumonia because they have relatively small lung capacity for their size and any disease damage causes problems," says vet John Yarwood. “Dairy calves are susceptible to pneumonia from a very young age and the disease is extremely common. In fact, you would be hard pressed to find any farm rearing dairy calves which has never had first-hand experience of this financially damaging disease.” Financial losses include deaths, high veterinary, labour and treatment costs and, significantly, depressed subsequent growth and milking performance in animals which appear to have recovered from the disease. Dairy cows only reach breakeven point halfway through their second lactation, but if they had pneumonia as a calf they may never pay back. When it comes to managing the pneumonia threat, the best form of defence is attack through good preparation and drawing up sound disease prevention protocols and, on many units, this means the implementation of a vaccination strategy. Mr Yarwood says: “Disease prevention should be your aim to stop pneumonia gaining a foothold on your unit. This way you will rear more resilient, faster growing dairy calves and minimise antibiotic treatments. “Reactive treatment is not ideal anyway for optimum disease control, because permanent lung damage may already have occurred by the time y o u notice a sick calf, and this certainly compromises growth performance. “We know if a dairy heifer calf puts on 1kg/day instead of 0.5kg/ day, it will produce an extra 1000 litres of milk in a lifetime.” He adds that many factors combine to cause pneumonia problems, such as calf housing ventilation, stress, infection pressure and calf immunity, for example.
BVD is one of the most important health concerns on Northern Irish farms and is highly prevalent in certain districts of the island. As of March 2016 a national eradication programme has been put in place involving tissue tagging, however even now in many localities farmer education has been poor and therefore knowledge of this particular disease is limited. Portglenone, County Antrim falls into this category and so vaccination uptake and eradication strategies on farm have been minimal over the years. For this reason it was high on our list of diseases to address for one of our Suckler and beef clients, whose work we took on after opening a new branch surgery in the area. Following months of frustrating fire-brigade veterinary work we discussed that perhaps a look at whole herd health and some diagnostic testing would be useful. Problems on the farm were numerous and included weak calves who were slow to stand and start suckling; scour and pneumonia in young animals, dietary upset in cows, poor cow condition and general queries over fertility. This was a farm where although the farmer was knowledgeable and nutrition was good there seemed to be an underlying immunosuppression issue causing on farm productivity and profitability to be poor. BVD is known to cause primary disease in the form of early embryonic losses and mucosal disease in persistently infected animals, however it is the secondary diseases which result in the most significant economic losses. These secondary diseases are primarily due to the immunosuppression caused by the virus as it is passed transiently through the herd.
On a Welsh dairy farm belonging to an agricultural college comprising autumn and  spring calving herds of crossbred British-Friesian and Jersey cows, BVD had become an issue. Both herds were expanded in size from approximately 150 animals in each herd in 2011 to approximately 260 in 2015. The initial problems were diagnosed as:
  • BVDV PCR positive on bulk milk tank two years after eradication program ceased
  • Higher biosecurity and biocontainment challenges on farm, namely rearing contract and increased herd size
  • Lack of motivation from farm manager to carry out new cycle of disease control and eradication
Due to the biosecurity risks identified in both premises, a thorough vaccination protocol was put in place on the bulling heifers. This will prevent formation of new PIs during the period of high risk on this farm. All newborn calves were tested for 12 months following the removal of the last PI from the farm.
Originally published in a special Pig World supplement (August 2018): A Harper Adams University (HAU) initiative, overseen by Guy Wade West from Garth Veterinary practice, sought to establish the value of a PRRS vaccination programme for piglets. The outcome, as expected, produced significant benefits to rearing herd performance in terms of growth and FCR, while also reducing the number of antibiotic treatments administered to finishing pigs.
Originally published in a special Pig World supplement (August 2018): Wayland is part of a regional PRRS control strategy, spearheading a vaccination-based initiative with other East Anglian pig businesses since 2016. The ‘PRRS: Preventing Recirculation, Regional Strategy’ programme has benefited piglet birth weights, weaner quality and sow fertility and helped tackle PRRS-related immunosuppression issues, which often manifest as secondary bacterial infections that require antibiotic treatment.
A first-generation pig farmer, who introduced the enterprise to his arable farm 20 years ago, Philip carried out the partial depopulation in order to eradicate a number of diseases. This has been very successful and has significantly reduced the amount of antibiotics used in the unit. Around 142 hectares of winter and spring barley are grown at Netherton of Mounie, with all of the barley being used in the pig units. Philip said: “Ninety-nine percent of what we sell here is pigs.” The breeding herd of 435 Landrace/Large White sows - with a Danish Duroc boar used as a terminal sire - are kept at Yonderton Farm, Ellon, about 15 miles away from the home farm and all pigs are transferred to Netherton of Mounie for finishing. However, the buildings at Yonderton for the weaned pigs were badly in need of an upgrade, so five years ago Philip took the opportunity to put all the pigs off the unit at weaning and build a new shed, while refurbishing another. He decided against a full depopulation, which involves all the pigs leaving the farm, as it would be costly and also create loss of cash flow. He explained: “Retaining the breeding sows meant we did not completely lose our cash flow during the depopulation period.” The young pigs were moved off site for eight weeks, while the sows were double vaccinated for Porcine Reproductive and Respiratory Syndrome (PRRS) and medicated for Enzootic Pneumonia (EP) and Actinobacillus Pleuropneumonia (APP). Meanwhile the finishing unit at Netherton of Mounie was emptied of stock for four weeks, thoroughly cleaned down and double disinfected. The result, according to Philip, has been a real boost in the performance of both the breeding and finishing herds. He said: “Conception rates have improved, as have numbers of piglets born alive, and numbers weaned have risen from around 24/25 to over 30 per sow per year. In the growing herd liveweight gains have improved to 850g/day from weaning to slaughter, while mortality has dropped to under two percent. The pigs are also reaching their finished deadweight of 86/87kg two weeks earlier.”

Bitesize Videos

Read antibiotic use case studies, showing how farmers and vets have implemented changes on-farm that have reduced, refined or replaced use of their antibiotics.

This video covers: Storage and use of the vaccine at the correct temperature; Using the vaccine at the correct time, interval, dose and route; Importance of good hygiene when using the vaccine and equipment; Ensuring adequate safety for people and animals involved; Ensuring accurate recording of vaccinations.  

Vaccinating cattle safely and effectively – AHDB

13 Aug 2018

Vet Rachel Clifton from the University of Warwick explains that vaccination for lameness in sheep is a whole flock procedure not just for individuals. It can help reduce lameness incidence if done as part of the whole five point plan.

Vaccination: sheep lameness series – AHDB

22 Aug 2018

Salmon farming has one of the most successful farm vaccination programmes in existence, protecting against the bacterial disease Furunculosis since the 1990s. This has virtually eliminated the need for antibiotic treatment to treat this condition.

Vaccinating young salmon smolts – Aqualife

08 Sep 2018

Pneumonia outbreaks have a serious effect on both the growth rates of young calves and their productivity as adult cattle. Preventing cases of pneumonia requires an all-round approach including use of vaccines to ensure cattle perform to their full potential, resulting in better returns for producers and a reduction in antimicrobial use.

Reducing pneumonia risk in beef and dairy calves – AHDB

08 Sep 2018

AHDB Beef & Lamb ran a webinar with Fiona Lovatt of Flock Health Ltd on the effective use of vaccines to protect sheep flocks from disease. Whether in the control of lameness or abortion or to prevent unwanted losses, the correct use of vaccination is important for a proactive approach to flock management.

Effective use of vaccines in sheep – AHDB

08 Sep 2018

This film brings together the key messages from the AHDB Calf to Calving programme, using interviews from host farmers and meeting attendees. It focuses on areas including colostrum testing, regular weighing, planning, vaccination, protocols and attention to detail. The video also features top tips for calf rearing.

Calf to Calving inc vaccination and colostrum – AHDB

08 Sep 2018

Vaccines are an important tool to use in herd health programmes, however, the success of any vaccine is dependent on good management practices. There are many important considerations which are covered during this webinar recording with Dr Wendela Wapenaar, Clinical Associate Professor in Cattle Health and Epidemiology from the University of Nottingham. Before Nottingham, Wendela worked in farm practice in The Netherlands, New Zealand, Canada and the UK. Her teaching and research involves cattle reproduction, biosecurity, infectious disease control within farm animal and effective knowledge transfer of research findings into veterinary practice.

Best practice for vaccination of beef and dairy cattle – AHDB

06 Oct 2018