As thoughts turn to next year’s lambing, ensure ewes are protected from toxoplasmosis.
The risk of buying-in replacement ewes of unknown vaccination status was firmly brought home to Welsh sheep producer Meirion Thomas in 2016 when 12 of 80 yearlings bought at autumn 2015 Mule sales suddenly aborted.
He says: “The flock scanned at 186 per cent in December with only 1.8 per cent of ewes barren. We normally scan at about 173 per cent, so I was looking forward to a decent 2016 lambing season.
“But an unusually protracted lambing period and the loss of lambs from these new ewes was upsetting and highlights how you can never become complacent with bought-in sheep.”
Having received assurances at the replacement sales, Mr Thomas had assumed the incoming yearlings had been vaccinated. Now he knows they were not.
He says: “We blood tested the ewes which aborted and our vet said toxoplasmosis was the most likely cause. I was extremely frustrated because we do vaccinate our own sheep and I was cross we had left the replacements vulnerable.”
According to the latest VIDA data, compiled by the regional APHA Veterinary Investigation Centres and SAC Consulting (Investigation and Disease Surveillance Centres) across Great Britain, toxoplasmosis is now the second most commonly diagnosed cause of abortion in sheep – after enzootic abortion (EAE) – but is definitely on the increase; rising from 8 per cent of diagnosable submissions in 2014 to 11 per cent in 2015.
Sheep pick up the toxoplasma parasite from the environment and normal biosecurity measures are not enough to control the disease. Infected cats shed toxoplasma eggs in their faeces and sheep become infected when they ingest these eggs from contaminated pasture, feed and water. The eggs are tough and can survive in the environment for more than a year.
Toxoplasmosis can be controlled effectively in ewes by a simple vaccination regime at least three weeks prior to tupping – the cost of which can be easily covered by a reduction in future flock barren and abortion rates.
Mr Thomas runs 570 Mule/Mule cross ewes and 50 suckler cows on 109 upland hectares (270 acres) between 36 and 168 metres (120-550ft) above sea level at Cefnbenydd Farm, near Llandovery. Over the years he has been a committed vaccinator against the infectious causes of sheep abortion, believing a proactive approach to flock health planning pays dividends.
He says: “I have vaccinated against EAE for 25 years and also started vaccinating against toxoplasmosis about 12 years ago having taken veterinary advice.
However, we did not do it for a couple of seasons a few years ago because the vaccine was unavailable and then in the third year only vaccinated about half the flock. Unfortunately, we then experienced abortion problems in the unvaccinated ewes.
“So with our most recent unlucky experience fresh in my mind I am now totally convinced about the need to protect replacements against toxoplasmosis.”
He believes too many farmers are burying their heads in the sand and says: “Unfortunately, many producers seem to accept unnecessary poor flock performance and lamb losses as part and parcel of sheep farming. Invest in proactive rather than reactive veterinary input and you will save yourself money and an awful lot of grief.
“And if your scanner tells you more than 2 per cent of your flock is barren, make sure you ask your vet to investigate because an underlying disease problem could well be about to surface.”