Apple Cider Vinegar for your rumins, and nearly every thing else...

If you fed the animals Apple Cider Vinegar, it will increase weight gain and reduce parasites, flies, and diseases.

Summary, put one pint of apple cider vinegar in every 40 gallons of water.

Here is a great writeup on it.
http://www.pharocattle.com/extrastuff/Misc/Apple_Cider_Vinegar.pdf