I have DE mixed in with the chicken feed at a rate of 1%. Does it protect them from internal worms? Beats me. It does provide a source of silica though. I like how it attracts any moisture in their feed so that we have less chance of mold growing in the feed. If it was truly bad for the chicken at 1%, then I'm surprised we don't have a high mortality rate. I guess, though, that considering they free range and have scratch available, the layers are probably only getting between 0.6% and 0.75% of DE in their total intake.
I think that we have fewer flies because of the chikens eating DE. The goats didn't get DE when we had them. The goat barn and corral had flies and the chicken coops and pens didn't. Since the goats have been gone, we still don't flies at the chicken houses. So, I like that we have so few flies. They say that if flies lay their eggs in chicken manure with DE in it, the larvae can't survive because of the DE in the droppings. I don't have a clue if it's true or not. My evidence is purely anecdotal and should certainly not be used as the basis for use of DE. There are just too many factors that can't be evaluated or measured.
Sometimes my chickens have mites even though they dust bathe in dirt whenever they choose to. It's definitely not every year, just now and then. I prefer to not use pesticides on the chickens since I have read numerous studies about pesticide use/misuse and some effects that seem worse than the condition I'm trying to avoid. DE continually takes care of the mite problem, a problem which also manifests itself as a mite crawling up my arm after collecting eggs. Thankfully, humans cannot be hosts for chicken mites. Yay! With broody hens, mites can become more of an issue because the broodies will sit there in the nest (or broody box) with mites living on them for weeks and then the chicks will have mites, too.
When I clean out the nesting boxes and then refill them, I use about a closed handful in each nesting box mixed in with the new pine shavings. My nesting boxes can be removed and all contents dumped at once. The DE can be placed in the shavings and mixed without much dust getting around in the air.
In my broody boxes, I use more DE ... probably three times as much, but broody boxes are larger than the nesting boxes. So....
I put on a mask when I sprinkle the DE into the cracks between the wooden fixtures and the supports in the coop. I don't sprinkle it in the litter since the layers don't spend any time to speak of in the litter on the floor and I don't want them to anyway. They are let out to wiggle their feet in clean fields, yard, pasture, woods.
If I think the mite problem is widespread, I have once or twice, filled an old sock with DE and tapped the back of each chicken on the roosts at night. The sock seems to help evenly distribute the DE into the feathers on their backs. I wear a mask for this. I wear a mask when I clean out the coop, too, because there can be all sorts of stuff in there that I think I can get sick from.
I have some chickens as old as 6 or 7 years old and none have started to show any signs of silicosis yet. But the jury is still out.
One thing is for sure, though, chickens seem to thrive in a myriad of situations which is great because we humans have a myriad different ways of taking care of them.
