Following one of the six strategies from the National Johne’s Management Plan is helping to deliver control of this challenging disease to farmers across the country.
Strategy 1: Biosecurity, protect and monitor
Chris Gasson from Redlands Farm in Hook Norton has a 450 cow unit, where all increases in animal numbers were from home bred heifers in order to maintain biosecurity specifically with Johne’s in mind. The herd is closed and has been for the past 15+ years, with the only incoming stock being bulls from level 1 accredited herds. The farm tests annually with a whole herd blood test to achieve accreditation.
Using a Biosecurity strategy based on a closed herd, a plan was formulated on the tentative assumption that Johne’s was not present on farm. From historical monitoring, any suspicious clinical signs were tested. These tests came back negative.
However, after an increased emphasis from milk buyers, the farm has become more active with monitoring. They have carried our several ’30 cow screens’ on milk samples and then progress to the accreditation route with the SAC. They have now carried out the first whole herd blood test in January which gave 3 out of 464 cow results to be retested.
The initial strategy was chosen as it was a low cost in terms of monitoring, and very little extra work for staff. At the time, no benefit was seen to become accredited, however, their view was soon changed, and now the blood testing will be piggy backed on the injection day of TB testing, so will not require much additional work or handling of cattle.
“The benefit is the pride we have in not having the disease on farm” says Chris.
“This is result of not having losses associated with the disease, including loses from culling, and other related cow health issues that have been reported such as increased lameness, somatic cell counts, poor fertility and reduced milk yields. It is difficult to put a financial cost on these, however, there are many reports on the drain that these cause in the literature and farming press.”
The farm’s stock does not have the physical manifestations of the disease of scouring and wasting cows which would lead to a degree of demoralisation amongst staff and the owner. There is no extra work and complexity of managing a herd with endemic Johne’s, such as, running two calving yards for ‘risk’ animals and ‘clear’ ones. There is also no need to identify cows to AI with beef sires, and those with replacement Holstein semen. Milk feed to calves does not need to be pasteurised, and there is no worry about spreading the disease in colostrum.
With the route Chris has chosen, they should meet the highest possible standard that is achievable.
Advice from the vet:
This approach needs to be dedicated with extra care taken when purchasing bulls; an alternative option could be to purchase embryos instead.
When planning to increase numbers of cattle it takes 3 years from deciding to breed more heifers to them entering the milking herd. So one of the first decisions to be made when expanding a unit, is to start the ball rolling with inseminating more cows to replacement semen.
There is also a degree of patience needed to do this. Chris believes sometimes that the decision to buy an extra 20 cows to put milk in the tank could cost much more than the value of the milk they bring if the biosecurity and purchasing decisions are not right.
– Plan for ‘disasters’ that would remove cows from the milking herd. Events such as an outbreak of TB, or other disease might lead to a shortfall in the number of cattle.
– Breed extra replacements – this gives options of what to do, the herd can be expanded, more selective culling of lame/low yielding/high cell count cows. Any surplus cattle after that could be sold.
– Chris also believes that in a ‘biosecurity, protect, monitor’ situation any positive serological results need further investigation and should be regarded as screening test, not a diagnostic one.