It seems that this season has been a bad one for Facial Eczema with places that are not usually affected being hit hard . What advice can people give to lower the risk of developing facial eczema in their flock - and limiting its impact
@Abi @administrators @Annie @becgreaves @Joanna-Purdie Hi there everyone, new to Rural Community (and it looks great), so here goes. Lots of great information shared above. As mentioned above management of this hideous disease does come down to personal farming goals which I guess will differ for everyone. Most goals will however most likely revolve around sustainability, profitability, environmental protection and ethics. That being said, breeding for tolerance is really the only strategy that covers all of the above. There are many ram breeders around the country that have highly FE tolerant sheep, and this doesn't mean that is all they have been breeding for. Fertility, growth etc are just as important in these flocks just as they are for everyone. Anyway, great to see the conversation being had and more information and where to find FE tolerant genetics can be found at www.fegold.co.nz
Here is the link to an article put out by B+LNZ on a farm reaping the rewards of investing time, money and energy into building a FE resistant flock. They also take the time to manage the risk by testing every paddock before 'high risk' stock classes are moved in. A great example of making informed decisions within a farming business and planning for success.
B+LNZ also have this article on how to breed for FE tolerance, which is well worth a read.
@Annie We only got a touch of it this year, and it is normally unheard of in our area, but it was bad in other areas I visited. We make sure stock have shelter, but once they are showing clinical signs the damage is done really! I have been told that once an animal has had it, even if they recover, they will probably pack up at some point e.g when under stress, like lambing time. The latest Country-Wide magazine just came out and is the sheep special - they have done a special feature on FE for those interested.
@Joanna-Purdie What a fantastic, informative response Joanna, thank you.
Does anyone else have any facial eczema experience to share?
It certainly has been a bad year for FE in our region. Toxic spores can build up very rapidly after a fall of rain (at least 4mm) where grass temperatures are over 12 degrees for 2 or more nights in row. This year we had conditions which allowed spore counts to build up well above the dangerous level and consequently we saw clinical cases of FE in flocks which don’t normally experience problems.
It is important to remember that the clinical cases (shade seeking, droopy ears, peeling skin etc) are only the tip of the iceberg. Many other sheep in the flock will have suffered subclinical liver damage. Some liver regeneration may occur, but some sheep will develop fibrosis (scaring) of the liver. These sheep will have reduced fertility, be generally ill-thrifty and will not tolerate stress well (i.e. lambing). Affected lambs will have reduced growth rates.
When it comes to limiting the impact of FE this year, unfortunately the horse has already bolted. The damage is done and the best we can do is to reduce stress as much as possible so that affected sheep might be able to cope. This includes feeding well and ensuring shelter is available, which can be easier said than done. In reality, sheep with badly damaged livers may really struggle or even die over lambing and may not cope during peak lactation. Unfortunately there’s not a huge amount we can do for them now.
For those hit hard, there is an opportunity to be proactive in future seasons. The danger period is generally late summer and throughout autumn, as conditions become favourable for accumulation of the toxic spores. In every region and on every farm there are ‘danger zones’ which will be more high risk for the build-up of spores. Risk areas include warm, north-facing slopes and sheltered paddocks or areas under hedges & trees. Exposed, windy hillsides or cool south-facing slopes tend to have lower spore numbers. It can pay to use spore counts (which can be performed by your vet) to help identify the danger zones on your farm and potentially try and avoid them during the risk period. Consider using a crop such as chicory, as spores tend to be much lower in this type of feed compared with ryegrass-dominant pastures. Hay or silage are other options. Hard grazing of risky paddocks during the danger period should be avoided because spores tend to be concentrated towards the base of the sward. Also note that pastures which build up lots of dead matter (i.e. pastures which grew too long in spring / summer or which were topped) are higher risk for accumulating spores, as the fungus which produces the toxic spores needs dead matter to grow.
Pastures can be sprayed with a fungicide to try and prevent growth of the fungus. Fungicide should ideally be applied before the spore counts rise. Follow up with spore counts to check the safety of pasture before grazing.
Zinc dosing is another protective strategy. Zinc will reduce the amount of liver damage, reducing both clinical and subclinical cases. It can be extremely effective at preventing FE in stock and is widely used in the dairy industry during dangerous times. However, the dose rates required to protect against FE are high and it is often impractical to get enough zinc into sheep. It can be given in drinking water but this may not be highly effective due to inconsistent water intake of sheep (i.e. if they have other water sources available). Zinc can be given in a weekly drench, but again this often isn’t practical due to the amount of handling required. Intra-ruminal bullets are available for lambs & sheep (as well as calves & cows). These release zinc over a 6 week period and are protective during this time. Any form of zinc must be given BEFORE sheep are exposed to high spore counts. Dosing should begin 2 weeks before the danger period (so get out your crystal ball!!).
Possibly the best long-term strategy is breeding for FE resistance. Some animals tolerate spore burdens much better than others and this resistance is highly heritable, so selective breeding can be used to create a relatively resistant flock. There are rams being bred specifically for this trait. I have personally seen this strategy in action and I strongly advocate it. I know of a few farmers who have selected for resistance and they reported very few cases of FE this year, with no other interventions. However, you can’t selectively breed for every desirably trait, so it is a personal decision whether FE resistance is a trait you would like to focus on within your farming system.
Hopefully this has been a little helpful to those looking to explore their options for next year and beyond :)