With Regard To Diatomaceous earth. I have been studying it and its benefits since 2000. With a focus on horse husbandry. it was suggested that feeding through was an excellent way to control parasites.... within the Gut. The DE would pass through to the manure and there it would really do its work.
In the manure pile it did a fabulous job slicing and dicing the parasites not allowing them to mature into adults. Reduced fly infestation. It also did some great things within the gut helping sweep out the smaller critters. Arguments that once it got wet made it ineffective ... I don't accept unless the animal ingesting the DE were also consuming an acid like vinegar.
My concerns over time came from the fact that Diatomaceous Earth should be applied with respiratory protection. We humans have far more lung surface area than Chickens do. Yet we Sprinkle it in their bedding and in their dust baths and even on them. All those sharp particles enter into their lungs and stay.
I don't have an issue with using DE as a preventative or as a feed through. I do have an issue with treating an infestation. with a dusting of DE. it doesn't act quick enough. I would rather treat the infestation With Ivermectin.... Not some cat and dog treatment... but that's me I understand horses and something I keep on hand... chickens have a very similar digestive system.
Digestion assisted by a Cecum filled with organisms that help break down the materials in the feed. DE is the perfect additive to this process. Working through the Gut.
Unfortunately there are parasites that do not require digestion to complete their evolution. they live in the muscle and the blood stream.... their final journey encistate (sp?) n the muscle.... meaning they pull in to make a larval hatching spot.... those are the ones that are protected by larvacide.... protected by their "shell" ...
Ivermectin has a long history of use within all these environments. Lung worms heart worms worms that live in the muscle.... You dont want them left to DE.
So I say. Use it for what its good for then back up with good medicine that works and doesnt leave the parasites resistant.
when I say good medicine I dont disregard DE value....
Past poultry: Buff Brhama, EE, Barred rock, Wellsummer,
Bantam mixes, Araucana, Turkeys, & Guinea Fowl.
Future poultry: Guinea Fowl, Sumatra, Wellsummer, Muscovy
"A dream without a plan is just a wish" Katherine Paterson