H.H. Stein, Division of Nutritional Sciences, University of Illinois, Urbana, IL 61801, USA
Mineral nutrition in pigs has evolved significantly due to recent research, particularly with the understanding of endogenous losses of calcium (Ca) and phosphorus (P) in the intestinal tract. This has led to the development of diets formulated based on standardized total tract digestibility (STTD) rather than apparent total tract digestibility, as STTD values are additive in mixed diets. Research has also highlighted the benefits of microbial phytase in increasing the digestibility of minerals and the negative impact of over-feeding Ca on pig growth performance.
In terms of vitamin D, the current requirements for growing and finishing pigs appear accurate, but there is evidence that gestating and lactating sows may need more vitamin D than currently recommended. The use of vitamin D analogs and metabolites, such as 1(OH)D3 and 25(OH)D3, may offer additional benefits when included in sow diets alongside vitamin D3. While research on other macrominerals remains limited, there is some indication that magnesium (Mg) levels might be marginal in diets with low soybean meal content. Chelated microminerals have shown increased digestibility compared to sulfate forms, and hydroxylated forms of copper (Cu) and zinc (Zn) seem superior to traditional sources.
Implications
This review emphasizes the importance of formulating swine diets based on STTD values for Ca and P, the careful management of dietary Ca to avoid negative impacts on growth, and the potential benefits of vitamin D analogs and chelated minerals.
