See Holly the problem with adding iron to any feed is that there is "normally" an abundance of it in the forage and no need to add it to balance the diet.
Horses with metabolic problems actually react to iron in feeds and it causes them MORE issues.
Purina is successful because of advertising NOT research.
Take it as close minded if you like SEA but I have done my research
Holly I will look for the livestock feed violations pages again might take me a bit they can be tricky to find LOL