Post Oak":jm1cusia said:
What's the best source of selenium?
A shot is a good short term fix, like for a sluggish calf, but to treat a cow that has it chronically, it hardly makes any sense.
Before calving (3-4 months) I feed a loose mineral mix that has about
100-125 ppm Selenium. We are very deficient in my area, perhaps you don't need as much... I sure noticed a difference in the frequency and severity of RP here, we went from about 3-4 cases a year down one every couple years. Copper is an important one too in may of the body's systems, including the immune system (and helps fight metritis associated with RP).
The best way to really know what minerals you need more of is to get a blood test done.. I'd do it on a couple heavy producing cows just before breeding time, or any cows that SHOULD be doing better than they are.