Is my horse getting too much iron from Redmond Rock and/or Daily Gold. Short answer: no.
According to the National Research Council (NRC), iron requirements for a mature horse are 40 to 50 ppm. This does not mean that a mineral tag that says 300 ppm of iron is too much. What it does mean is 50 mg per kg of feed. The average horse eats around 12 kg/day so the iron requirement would be around 600 mg/day with the range being from 500 to 1200 mg/day depending on size and exercise levels.
It is very important to note that forages contain well over these amounts and the NRC also states that horses should eat 2% of their body weight/day of forage. So horses are consuming far more than the suggested amounts of iron. But why wouldn’t that be the case? After all, iron is the 4th most abundant element in the earth’s crust and horses have been grazing for centuries without issues. So this kind of variation in the literature is normal. Mineral requirements are not an exact science by any stretch, and when you consider the form each element is in, how many of all the other 90 elements the horse is getting and in what ratios, and the relationships with all the other digestive microorganisms, this mineral interaction web is extremely complex. Challenges usually occur when we stray from normal and natural nutrition.
So what about Redmond Rock and Daily Gold? Of the suggested 500 to 1200 mg/day, Daily Gold provides around 114 mg/day and Redmond Rock around 20 mg/day, far under the minimum requirements. We’ve been feeding horses and all kinds of other animals for decades with a proven track record of improvements in health and production with Redmond product inclusions.