•Poorer feed conversion rates;
•Higher incidence of other diseases;
•Financial losses at slaughter.
If we move on from there to look at certain aspects of grassland parasites, we find a few more interesting facts:
•An adult fluke can produce up to 50,000 eggs per day -- This is a serious operator. The adult fluke in the liver of either sheep or cattle is pouring out many thousands of eggs each day. Those eggs need to hatch and make their way to the mud snail in order to further develop the life cycle. Hence, the presence of the mud snail (damp and wet-type soils) on the grassland makes that grazing area a 'flukey field'.
Here we find further multiplication of the issue. Each hatched egg has the potential to produce up to 600 infective larvae onto the grass, to be picked up by our young, vulnerable sheep.
•Each egg can produce up to 600 infective larvae -- This one parasite can multiply quite a few million times in one life cycle. And now we know why it's vital to have an effective control programme. We'll never rid the country of parasites but we can surely make life a lot harder for them. In the case of fluke control, we note:
•Bio-security is important when buying in new stock. Dose them and hold them apart for up to 48 hours before allowing them out to pasture;
•Avoid wet and marshy areas that are known to contain fluke;
•Hit the snails' habitat where possible by drainage, or by the use of molluscicides;
•In mixed grazing enterprises, it's vital to dose all animals at one time when tackling fluke;
•Information back from the factory floor is vital when setting out a control plan.
We mentioned Clover Meats' policy of directly informing the farmer of each and every fluke incidence in livers at slaughter. This should be industry-wide, with that information helping to tailor the control programme up or down, according to post-mortem findings.
Where there is fluke, there are also worms. This becomes important at dosing time where we wish to cover as many problems as possible with one dose.
It's easy to use a combination product claiming fluke and worm efficacy when in fact, two focused products may be better.
•Drug resistance in worldwide fluke populations has grown to an alarmingly high level -- Drug resistance builds up with over-use, under-use and with every use of any medicinal products. Therefore, we should choose our medicines carefully, and only use them in a specifically focused fashion.
In the case of flukecides, few are effective against early immature fluke. Others are useful against immature fluke of six to nine weeks of age, with the rest effective against only the adult fluke of 10 weeks or older.
So when we see a combination product claiming to kill fluke and worms, we need to ask how effective is the fluke part and the worm part.
When dosing sheep we must think, what exactly are we trying to target? Which leads to the next final frightening fact:
•€2.5bn is the worldwide cost to the industry by fluke alone -- This is a fact presented to us by Animal Health Ireland. Most infection at this time of year comes from snails that have built up over the summer on pastures. Use faecal egg counts and post-mortem information from the factory to help put together an effective control plan. Let's stop that slow puncture. Give those lovely young livers a chance to thrive without the burden of parasites.
Peadar Ó Scanaill MVB MRCVS is a member of Veterinary Ireland's Animal Health Committee and is a vet in Ashbourne, Co Meath. Email: HQ@vetireland.ie