Study on Fowl Mites - Dustboxes - Sulfur vs. Diatomaceous Earth or Kaolin Clay

[Snag]

I've been lurking on your forum for several weeks, having just started my first flock. I've been reading about the use of Diatomaceous Earth in a dustbox as a form of mite control. I just ran across this U of C study (published 3/28/2012) on Pubmed.com and thought it worthy of officially joining the forum so I could bring the info to you. I don't know if it has been peer reviewed or the number of chickens involved in the study. What I found most interesting was that while the DE and kaelon clay reducted parasites by at least 80% on dustbox user hens, while the sulfur product was effective even on non-dust box user hens after 2-4 weeks and, even after the dust boxes were removed, had a 9 week residual impact on all hens.

Snag

Med Vet Entomol. 2012 Mar 28. doi: 10.1111/j.1365-2915.2011.00997.x. [Epub ahead of print]
Housing and dustbathing effects on northern fowl mites (Ornithonyssus sylviarum) and chickenbody lice (Menacanthus stramineus) on hens.

Martin CD, Mullens BA.
Source

Department of Entomology, University of California Riverside, Riverside, CA, U.S.A.
Abstract

Hen housing (cage or cage-free) did not impact overall abundances of northern fowl mites, Ornithonyssus sylviarum (Canestrini & Fanzago) (Acari: Macronyssidae), or chicken body lice, Menacanthus stramineus (Nitzsch) (Phthiraptera: Menoponidae). Cage-free hens received a dustbox with sand plus diatomaceous earth (DE), kaolin clay or sulphur. Weekly use varied from none to 100% of hens; 73% of hens used the dustbox at least once. Ectoparasite populations on dustbathing hens (users) were compared with those on non-user cage-free and caged hens. All materials reduced ectoparasites on user hens by 80-100% after 1 week of dustbox use. Diatomaceous earth and kaolin failed to reduce ectoparasites on non-user hens, and ectoparasites on user hens recovered after dustbox removal. A sulphur dustbox eliminated mites from all hens (including non-users) within 2-4 weeks. Residual sulphur controlled mites until the end of the experiment (up to 9 weeks), even after the dustbox was removed. Louse populations on hens using the sulphur dustbox were reduced in 1-2 weeks. Residual sulphur effects were less evident in lice, but the use of a sulphur dustbox by a higher proportion of hens extended louse control to all hens. This is the first experimental study to show that bird dustbathing in naturally and widely available dust materials (particularly kaolin) can suppress ectoparasites and thus the behaviour is probably adaptive.

2012 The Authors. Medical and Veterinary Entomology

2012 The Royal Entomological Society.

 

[PeterNaomiGray]

Snag:
Interesting. I found the same study, with the complete paper, at http://www.thepoultrysite.com/articles/2470/novel-control-of-fowl-mites. Our chickens recently contracted mites for the first time that we know of, and it brought to mind that years ago I used sulfur powder as a very effective treatment against chiggers, in Kentucky and Arkansas. While fairly well educated in entomology, it's not my field, but I am familiar with experimental design, statistics, and professional publication standards. This journal looks very reputable to me, and so does the paper. I'd be very surprised if it wasn't peer reviewed. The number of experiment runs and the sample size are fairly small, but they probably don't need to be a lot larger to get useful results. Statistics and experiment design look quite good, and everything's carefully described so that anyone could replicate it.
Because of the small data sample, the variance in results is pretty high, as one would expect. I wouldn't put much stock in the difference they found between DE and kaolin (essentially equivalent to common yard dirt); with kaolin appearing to be somewhat more effective. That does suggest that the important issue is whether the chickens get properly dusted, and if typical clayey soil works just as well as DE, maybe it's not worth paying extra for it (although the convenience and consistency might be worth it).
But sulfur came out dramatically better than the other two. As you mention, the persistence of its effect, and the way that sulfur wiped out mites in non-bathing chickens, indicate that sulfur is the best available non-toxic mite treatment. It's cheap, too, only slightly more per pound than DE, and you don't have to use nearly as much of it. I ordered some on Amazon at $25 for 10 pounds, and I plan to try it soon. I haven't found or heard of any good reason not to add some to the birds' dust bath areas, and treat the likely mite hideouts in the coop as well.

Peter Gray
Washington State

 

[chfite]

One more step that might have been worth considering would be to compare free ranging chickens who bathe in the native soil. I know studies cost money, but it would be interesting to have that information versus chickens kept in just coops or with runs.

Sounds like sulphur is a winner.

The more we know, the better off we can be.

Chris