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Healthy sheep are thriving sheep, which ultimately means more kilograms of lamb weaned and sold each year.
But a healthy flock does not come about by chance. It takes planning and good management, as no two years are the same.
The key thing is to have a framework for disease prevention that covers the main risk periods to flock health.
As part of the programme, a flock health plan is being drawn up between the farmers, programme adviser and local vets.
Simple and effective
When it comes to a health plan, it must be simple and straightforward to be effective. An overly-complicated plan is unlikely to be followed, and therefore is a pointless exercise.
For sheep farmers around the country that do not have a health plan in place, there is no better time to complete one, as management priorities transition from lambing to grazing management.
Outlined are some steps to drawing up a health plan.
What have been the main recurring diseases on-farm?
The starting point for any plan is the flock history. Identify the main health problems over the years.
Next up is to identify the time of year when these problems occur. For example, turnout to grass post-lambing, fly strike in summer, or lameness at housing.
These are the health problems to target first. Once you get on top of the bigger problems, it is easier to focus on the smaller, less regular issues.
More often than not, once the bigger problems are sorted, there are fewer underlying health problems.
This comes as the sheep’s immune system is not suppressed, leaving it less exposed to secondary infection.
Break the year into seasons or key management periods
Break the year down into four or five key seasons to manage the risk periods for different stock groups.
For example, start with lambing and spring turnout, followed by late spring and summer management, breeding and winter/pre-lambing management.
Prioritise sheep groups
Mature ewes will have greater immunity than flock replacements and lambs. Therefore, timing of treatments is even more crucial in younger animals.
When treating lambs, be careful of withdrawal dates when treating animals destined for slaughter.
Bought-in replacements should be quarantined as a separate group until they are on the same vaccine and parasite programme as the main flock. This can reduce transmission of diseases such as footrot through the flock.
Choosing the right product for parasite control
Anthelmintic resistance is a growing problem, so it is important that you are using the right product to treat animals.
Do not repeatedly use the same wormer and fluke product year in, year out. Talk to your vet about rotating products every so often, thereby cutting down the level of resistance within the flock.
Also, it is important that you take the time to administer the correct dose according to the product guidelines. This means securing sheep in a handling race for any routine treatment.
Review, monitor and cull persistent offenders
Planned treatments are just one part of the puzzle. You need to check that your health programme is working.
Generally speaking, the incidence of health problems, and thus treatments, on your farm should fall year-on-year. For example, has the number of sheep with lameness reduced?
There will always be a handful of persistent offenders and these animals should be marked for culling.
Taking a few faecal samples will indicate if worm/fluke treatments are effective.
If not, a change of product may be required. Faecal sampling can also be used to determine when to treat animals, cutting down routine treatment and saving money.
Clostridial diseases
Clostridial diseases are caused by soil-borne bacteria. Common symptoms include sudden death in sheep, especially lambs.
When ewes are being fed concentrates at grass, lambs often lie to one side of troughs to shelter from wind or rain.
As soil exposure is greater in these areas, the risk of clostridial diseases is increased, especially when ground conditions are wet.
The same applies to lambs grazing lower grass covers, as the risk of ingesting exposed soil is higher.
Therefore, make sure lambs are covered with an appropriate vaccine targeting clostridial diseases and move troughs regularly.
Where ewes were vaccinated, the antibodies transferred via colostrum will generally cover the first three to four weeks of the lamb’s life.
Coccidiosis
Similarly, where young lambs are grazing on heavier, wetter land, flock owners should be on the lookout for signs of coccidiosis in young lambs under two months of age.
The risk is increased where lambs come in contact with contaminated feed troughs, so make sure to move troughs once ewes start poaching. Troughs should also be cleaned before use.
Look out for lambs with a dark scour or showing signs of straining and rapid weight loss.
Lambs do develop immunity with age, so the risk period is mainly confined to animals in the first few weeks of life.
Nematodirus
With the dry grazing conditions at present, there will be a relatively low build-up of nematodirus on pasture.
Don’t be fooled into a false sense of security. With temperatures rising, there will be a rapid increase in nematodirus levels once the current dry spell ends and rain returns.
In such instances, lambs can ingest significant numbers of nematode eggs. It takes around three weeks for these eggs to mature and show the usual tell-tale signs of diarrhoea and weight loss.
Therefore, be alert to such symptoms over the coming weeks and be ready to treat animals once you notice around 10% to 20% of lambs affected.
Liver fluke
Despite the recent upturn in weather conditions, it was an extremely wet winter and spring.
As such, ewes grazing during January and February, before housing for lambing in March, will be at risk from liver fluke over the coming weeks.
These animals should be treated with a flukicide as they go back to grass. Ideally, use a different flukicide to the products used in autumn and mid-winter.
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