I have one dairy cow. I read in dr Jarvis book, Folk Medicine, about how a daily dose of apple cider vinegar for a dairy cow will prevent mastitis. So as soon as I got my cow, I started her on vinegar. She was pregnant when I got her, and so when she had her calf, she had no problem, easily delivered, which is a side benefit of vinegar. She is now 9 months into milking. She went through the wet spring, when all my friends' cows got mastitis. She hasn't had a hint of mastitis. She hadn't been sick in any way. I cut up high protein hay and mix it with sweet feed for her to eat while she's milking, and I pour some pasturized apple cider vinegar over her feed. I don't measure the vinegar, I just give her a "pour." She loves vinegar, apple and pears. When I am leading her in or out of a gate, if pears are in season, I have one in my hand to give her. Pears and apples have the same nutrients as vinegar, but making them into vinegar makes them shelf stable for use in the wintertime.