Avoid any copper at all costs. Each animal has it's own tolerance level... why toy with it.
I've have seen 15 healthy ewes dead in 24 hrs because a grain mixer at a feed mill wasn't cleaned well enough after mixing another type of grain. You don't want to go there.
Give .5 cc's of BoSe to lambs at birth if you are in a Selenium deficient area. This is the most common mineral deficiency in sheep. Make sure all sheep have free choice sheep minerals available at all times... notice... NOT just any mineral, but sheep mineral - you don't want just any mineral as most contain copper.
To combat parasite loads in the lactating ewes you need to evaluate your ration.
Make sure it is balanced, that they are getting at least 180 RFV alfalfa and/or a grain ration (preferably not pre-packaged as most contain antibiotics and/or decox) with yeast and selenium added.
This is if you are milking them twice daily.
If you are leaving lambs on you want to lower their input, which will lower milk production, but help lower the potential of mastitis also.
One thing folks need to understand about sheep and parasites... all sheep have them.
It's how they handle the load they have that you can help control. A ewe with a higher plane of nutrition can better handle a higher parasite load.
As an aside... if you have barber poles you might want to consider something with moxidectin in it. Barber poles can kill even a very healthy sheep very quickly. Aside from that (and those are usually only a problem in mid-summer) you should be able to control parasites with nutrition.
Our philosophy is... if you can't control parasites with nutrition, get rid of that sheep!
Hope that helps.
