Very interesting. The open circles or squares represents birds on the control group that had no DE either fed to them or rubbed onto or into their feathers.
The groups represented by the black circles or squares on the other hand all were treated with DE. I looks that by the 34th week of the...
If it is bad for your hens to inhale DE then what is happening when a hen plops herself down in a dust wallow to which DE has been added, often for years and she begins to throw dust & DE all over herself?