I have done a lot of reading about DE and goats. I have not had a chance to experiment myself yet, but this is what I have found.
DE kills by contact with the worms, so you have to take enough of it, take it long enough, and also remember that it will only kill the worms in the digestive tract. Any other worms, such as lung worms, will need another dewormer.
Amount: For Nigerian Dwarf's you need at least 1/4 C a day for 3-5 days per goat. You will need more for larger goats, however the breeder that I am getting this information from has only Nigerian Dwarf's, so I don't know how much, I guess you could figure it out by weight, the average Nigerian Dwarf should weigh around 75lb.
ETA: The breeder that I read about this just mixes the DE up in with her damp grain and her goats eat it that way. I have tried that and my goats will do everything they can to avoid eating the DE (including not eating the grain) so I will have to figure something else out.
I just had a vet tell my that DE is a big scam. He said it will not kill internal or external parasites. I have a bag that i use for my chickens to help wart of lice, ect, and he said that also is balony. I have never had any parasite problems, but now I'm a bit hesitant to say it was because of the DE. One thing is does provide is a great source of trace minerals when mixed in feed. I will continue to use it until this bag is gone, but not so sure I will pay that much $ for another bag.
To find out if DE is a scam or not a simple trick should prove it. Go get an earthworm, maybe some beetles, whatever buggies you can catch. Put it in a plastic container and sprinkle some DE directly on the critters. Make sure they have air to breath and a small amount of moisture so they don't die from lack of either!
It killed my mom's chicken mites very well. I'm getting ready to dust my goats with it for lice, and as soon as I quit procrastinating I'll try deworming them with it.
Green family Farms, how much did you use? Most people use only a TBS or so per goat. That is NOT enough.
Red Lake Earth is registered as an anti-caking agent and pelleting aid for use in livestock feed. Many people find it useful for various other purposes however, these are only testimonials and results are not based on scientific facts.
However, research on the product continues to be done. In fact, a recent study published in Poultry Science found amazing results when using DE with chickens including increased egg production and decreased parasites.
A link to a pdf file of the study can be found at www.absorbentproductsltd.com however, due to copyright permissions, the study can only be viewed and not printed or copied.