Why producers should monitor iron levels in animal feed
Iron is a critical element in monogastric animal nutrition: not enough, and anemia surfaces; too much, and colibacteria proliferate.
Monogastric animals, like pigs and poultry, do not care about how much iron we incorporate into their feeds. In fact, they can tolerate wide excesses, whereas natural ingredients contain almost enough to allow them to live at an acceptable, albeit not profitable, condition. However, we should be quite vigilant about iron in feeds. There are certain conditions — for example, using exotic ingredients — that could exacerbate a marginal iron deficiency. Or, as another example, when too much iron from using the wrong phosphate salt could provide a surplus of iron that causes gut Escherichia coli to proliferate at an excessive rate.
It is imperative to consider all aspects of iron nutrition.
Traditionally, nutritionists have relied on a trace mineral premix to cover the needs for iron, almost invariably, with a generous margin over requirements. Today, this is no longer considered as good enough. First, because we know better, and second, because we must ensure animals receive only as much iron as they need and no more or less. In addition, it is not sufficient to determine an absolute concentration of iron supplementation, say 100 ppm, from the premix. We must know how much of this amount actually becomes available to the animal. In other words, we must understand and take into account the factors affecting iron availability:
Iron sulphate is considered as the golden standard in iron relative bioavailability studies, given an arbitral value of 100 percent. This does not mean iron in iron sulphate is 100 percent digestible…