Figure

Fig. 1.4. Modified Liebig’s barrel illustrating the concept of first, second, third, and so on, limiting essential nutrients in animal nutrition: in this case amino acids. A full barrel represents the potential animal performance if all essential amino acids are present in non-limiting quantities. In this case, lysine is the first-limiting amino acid, followed by methionine, then threonine. New evidence suggests that there is an additional response (dotted hoop) if the non-essential amino acids are provided in addition to the essential amino acids (Wu 2014). Some nutrients present at high levels in feeds or water can induce a deficiency of another essential nutrient (this would be represented as a very long stave reducing the length of another stave). High K levels, for example, induce a deficiency of Mg in ruminants.