This seems to be the general rule of thumb on here for the Ivomec Pour-On for cattle - available at most feed stores.
I believe the Eprinex is also the same doseage - but does not have a withdrawl period for the eggs. With regular Ivomec you should not eat the eggs for a few weeks after treatment.
I'm not sure if you need to re-treat in 7-10 days though like you would using permethryn - maybe someone else will know.
If you have a problem with lice/mites, be sure you also clean your coop at the same time - remove bedding - dust/spray the coop with poultry dust, 7, or similar, and put in fresh bedding. Mites will live on and off the chicken - lice generally stay on the chicken.
Ivomec pour on dosage is as follows
1ml for full grown turkeys
0.5ml for half grown turkeys
0.5ml for large chickens
0.25ml for bantam chickens
Placed on the skin in an area they can't reach - like flea drops for dogs.