They are due to be re-tested 3 weeks after worming, so at the end of the first week in April. This is the time lag advised for hens with a bad worm burden, to kill off any residual eggs that may have hatched in that time, so it should show if they have all been cleared, including the one bird which tested positive (Marigold, of course!) What I was interested in was that my giving the dose by the treats method in the past, and at a half dose rate, was effective since 3 out of 4 birds tested had a negative result 5 months later, just before being wormed.. This means that the egg count was below the level where treatment was considered essential, not that they were completely worm-free. Emma Nelder, the student running the tests, says;
'Because of the way the test is run the lowest egg count that it can detect
is 50 eggs per gram, so a negative result doesn't necessarily mean a
complete absence of worms, just that there are very few prodcing eggs are
that time. If one hen had a positive result then chances are the others
may well have had at least the beginnings of an infection, just perhaps
with worms that weren't yet mature enough to start producing eggs, so
worming them all probably wasn't in vein!'
I've always thought that giving the right dose of Flubenvet was a bit hit and miss, with all the variations of appetite, condition of birds, cleanliness of runs and pasture etc, so since the treats method appears to have worked previously, I shan't shut them up on a restricted diet in future. I suppose I should increase the dose, though, now I know how much feed they would get through if not finding any from foraging in the garden for greenstuff etc. Previously I've added enough Flubenvet for the 3 kilos I thought they would eat, mixing it in with seven eggcupfuls per hen of attractive seeds and grains, and giving one eggcupful of the mixture per bird in the afternoon. This went down the hatch in a flash every afternoon with no trouble at all, and no need to change anything else about their diet or routine. I suppose I can still do this, although maybe double the dose to what they would eat in 6 kilos? But then, if the half dose was effective, should I do this?
All very interesting!