With the Regional Development Programme for England’s (RDPE) current ‘BVD Free’ campaign coming to an end next month Katie Jones speaks to DairyCo’s Elizabeth Berry and three livestock producers to hear more about why farmers should adopt a hard stance on the disease.
It is estimated 90 per cent of UK cattle herds have been exposed to bovine viral diarrhoea (BVD) and with active BVD virus costing £50 to £100 per breeding animal it pays to monitor and eradicate the disease from your herd.
Dr Elizabeth Berry, from DairyCo, explains the disease can have huge effects on cattle including problems with abortion, infertility and calf pneumonia, and in the most severe cases death caused by mucosal disease.
She says: “It is, however, one disease you can actively do something about. Every farmer who has proactively tackled BVD says it is the best thing they have ever done in terms of improving animal health. And most only wish they had done something about it sooner.
“It is a disease, which is easily controlled, which has been shown by other countries adopting a national eradication scheme in order to eventually become BVD free.”
Campaign
The ‘BVD Free’ campaign, has embarked on a programme of knowledge transfer, with the main aim being to explain to farmers and associated industry representatives, why they would want to eradicate the disease within their own herds.
“Being BVD free has many long-lasting effects on your herd, from improved fertility to reduced incidence of calf scours,” says Dr Berry.
“To ensure we get the message out far and wide we have focused on all aspects of cattle production from calf buyers through to dairy farmers and beef producers.”
While Scotland and Northern Ireland are already engaged in compulsory eradication schemes there is no similar policy currently in place for England and Wales.
“While we are quite happy for the time being to continue with this voluntary phase of BVD eradication, it may soon get to the point where a compulsory scheme will be needed to get to those farmers who are not already doing something about it,” says Dr Berry.
Tell-tale signs of BVD
- Unexplained thrift
- Poor fertility performance with increased barren cow rate
- More unexplained abortions than normal
- Calves scouring and having more pneumonia than expected
- Sick calves responding poorly to veterinary treatment
Simon Bainbridge
Case study – the suckler herd
For Simon Bainbridge optimum performance within his 140-cow suckler herd cannot be achieved without maintaining a high health status.
However, achieving and appreciating the importance of this high health status came only after learning some difficult lessons.
Back in 2005, problems were first identified at Mr Bainbridge’s 660-hectare (1,650-acre) farm in Northumberland, when two cows aborted and tests came back inconclusive. Prior to this, the herd had not been vaccinated against BVD, and the disease was not perceived to be an issue. However, this failure to implement a vaccination policy had left the herd naïve to the virus.
Mr Bainbridge says in 2005 there was also an unexplained ‘gap’ in the calving pattern. “Then, during November and December of 2006, an outbreak of mucosal disease was diagnosed in the weaned calves.
“The symptoms ranged from sudden death to subdued animals which quickly became ill and died or were euthansed.”
In total, 18 yearling calves were lost and 33 calves affected during 2006. Initially blood samples were taken from calves which appeared to be unwell and any calves found to be PI were removed.
The estimated costs of veterinary time and treatment and the loss of animals were in the region of £25,000.
This loss figure, however, is for the 2006/2007 year and does not include losses for the year before and after the BVD outbreak, adds Mr Bainbridge.
The total sum of the BVD outbreak on the farm will have been higher, possibly twice this sum. Mr Bainbridge says: “The financial losses would be nearer £60,000 should it happen today – the value of beef having markedly increased over the last seven years.”
Once there were no further losses, the search was on to find the source of infection and the whole herd was tested to see if they were PIs. Amazingly only one calf born from the 2006 spring calving herd was found to be a PI.
Infected in-calf
Tracing the mother of this calf showed she was not a PI, which meant she must have been infected while in-calf. The source of the original infection is still not known today.
“Implementing a vaccination programme, without knowing how long the disease had been grumbling in the herd, could only be done once any PI animals were culled,” says Mr Bainbridge.
“Vaccinating PI animals does not cure them and they would have been a constant source of infection on the farm. PIs also give birth to PI animals and just continue the vicious cycle, especially when retaining replacements.”
A sample of blood is now taken from different groups of calves every year to check for antibodies and virus and the herd continues to be vaccinated.
Mr Bainbridge says a tight calving pattern makes it easier to administer the BVD vaccine before they go to the bull, in addition to other vaccines and treatments.
Since vaccinating and removing the PI animals, not only has the loss of yearling calves to mucosal disease stopped, but Mr Bainbridge says it has ‘without a doubt transformed herd health’.
“It has helped in tightening the calving pattern and those niggling losses and pneumonia problems in younger calves have stopped and overall calf health improved.
“This was an extreme outbreak which forced me to address the problem head on. The financial and emotional strain was extreme. I would hate anyone to have to go through what we did.”
Bainbridge Farms
- Family run organic farm of 140 suckler cows and 1,400 breeding ewes
- Most of the land is in a Severly Disadvantaged Area and moorland and red clover/grass silage is grown along with wholecrop, lucerne and spring oats for winter feeding
- Heifers calve more than six weeks and the cows calve more than nine weeks
- Calves are all fattened on the farm and sold direct to slaughter from 18 months to Dovecote Park through the Waitrose scheme
- The farm joined the SAC premium health scheme in January 2007
Herds without a BVD vaccination policy will be naive to the disease.
Case study – the calf supplier
FOLLOWING requests from buyers wanting to maximise calf health, and also requests for BVD free stock, Peter Jones Livestock is now pre-screening all calves before they enter rearing units.
The company’s Peter Jones explains calves identified as PI will not be sent onto rearing units.
The company supplies everything from young calves, reared calves, store cattle and breeding stock to all sectors of the beef industry.
Calves, which are bought from a variety of sources including markets, are now tested on the day of purchase, prior to delivery. To do this Mr Jones is using a lateral flow device, which is similar to a pregnancy test kit.
Each calf being tested has an ear notch taken and then the test is run, giving a result in 15 minutes.
Mr Jones says: “Pre-screening any new stock coming onto the farm, means the risk of introducing BVD will be avoided for any existing stock belonging to that farm.
“This will mean the finisher can be more confident about the health status of the animals on their unit. As some calves are reared for breeding stock, it will also mean buyers can be confident in the stock, and as long as the breeding stock is kept away from PI calves they themselves will not produce PI animals.
“By regularly testing for BVD there is potential for huge savings to many farm businesses through the reduction in abortion and reproductive losses, improved calf health, improved mortality, and reduced veterinary costs,” he says.
Poor fertility, just one of the signs of BVD, can hit finances hard.
Case study – The dairy herd
DAIRY farmer Peter Baul, recognises the threat BVD could have on his business, which relies on the selling of replacement heifers, as well as the monthly milk cheque.
Mr Baul, who farms at Watergate Farm, Harrogate, says the loss of heifer calves, or poor fertility, would financially hit the business hard. So he has been working closely with his vets, Bishopton Veterinary Group, to eradicate the disease from his closed 200-cow pedigree Holstein herd.
Mr Baul says: “BVD was not an issue until four years ago when we began to notice some problems. A heifer with respiratory disease along with multiple oral lesions was tested and confirmed as a PI animal.
“This all tied in with previous fertility issues in heifers which were in-calf to a beef bull, which did not belong to the farm and could have been infected with BVD.
“The heifers had not been protected by BVD vaccine due to administration errors and youngstock screening did not include this group.”
Milking cows, dry cows, in-calf and bulling heifers and youngstock were blood sampled and pooled BVD antigen test carried out. This revealed more PIs in the milking herd and in the youngstock, which were removed.
Early testing
Mr Baul says to check no other pregnant animals were carrying a PI calf, early testing and removal of any PI’s was essential.
“We decided to ‘tag and test’ all calves born. This meant all calves were tagged shortly after birth, as normal and a small tissue sample collected and sent away to be tested for BVD.
“Knowing your BVD status and regular surveillance is essential on every farm allowing you to decide whether monitoring and biosecurity or testing and eradicating are your main priorities.”
Moving forward a strict vaccination protocol has been re-implemented, along with regular bulk milk BVD antigen testing, and heifer cohort testing using blood samples and checking of hired stock bulls.
Mr Baul says the need to continue monitoring is essential and driven by the continued risk of infection and the fact a vaccination will not cure PIs.
“PIs will also give birth to PI calves, which continues the source of infection.”
Moving forward Mr Baul will continue to test newborn calves for BVD, for at least another year, despite the last PI already being removed.
He adds they are trying to avoid grazing bulling and in-calf heifers in perimeter fields next to neighbouring cattle to avoid contact with possible infected animals, and double fencing is also being considered for the future.
Source: Farmers Guardian
