I'm trying to figure out if our land is selenium deficient. I looked it up on the map linked in the Goats 101 section and it says the parish we're in (Livingston Parish, we don't have counties in La) has an average of 0.387 ppm but anywhere between the min of 0.108 and the max of 0.687. But we live close to the parish line, so I'm wondering if I should take the next parish (Tangipahoa) into account... which is 0.214, with a min of 0.100 and a max of 0.429. (This is the map: http://tin.er.usgs.gov/geochem/doc/aver ... stern.html we're like to second furthest on the left, 4 parishes from the bottom, TMI probably but I don't know if it matters.) What do these numbers mean exactly? lol. How can I find out where exactly my land stands? How much should there be? Should I just copy other people in Southeast La? If I do need to add selenium, is it all premixed in the feed or whatever or do I need to figure out doses according to how much we have?