Effect of Dietary Yeasts Enriched with Cu, Fe and Mn on Digestibility of Main Nutrients and Absorption of Minerals by Growing Pigs

Yeasts Saccharomyces cerevisiae containing in 1 kg of dry product, separately 32.0 g Fe (Y-Fe), 23.0 g Cu (Y-Cu), 35.4 g Mn (Y-Mn), were used as the source of these microelements in complete diet for growing pigs. If considering livestock requirements, feed supplementation with this organic form of microelements, covered animals’ requirements in: Fe-27%, Cu-75%, Mn-30%. ZnO was the source of zinc. The experiments were carried out on 25 barrows. Digestibility of the main nutrients, the apparent absorption and balance for Fe, Cu, Mn as well as Zn, Ca, P, Mg, were carried out. The supplemented microelements did not have the adverse effect on digestibility of the main nutrients and the apparent absorption of Ca, P and Mg. Barrows fed with feed containing Y-Fe excreted more iron with urine than the control, which statistically significantly (P<0.05) influenced decrease of retention from 67.4 to 58.0 %. Absorption was similar in both groups. The supplementation of Y-Cu had the influence on increase of retention of Cu up to 25.6 % and absorption up to 28.1 % when compared with the control group (21.3 and 23.7 %), respectively. Supplementation of Y-Mn also significantly (P<0.05) increased Mn retention up to 20.1 % and absorption up to 21.4 % when compared with the control group (12.8 and 13.8 %, respectively). Joint supplementation of Y-Fe, Y-Cu and Y-Mn did not improve retention and absorption of all the microelements. In the group Y-Cu, significant (P<0.05) decrease of retention and absorption of Zn was observed when compared with the remaining groups. It was found that in pigs feeding, yeasts enriched with copper and manganese may find application in practice. However, yeasts enriched with iron, were found to be less efficient than inorganic form of this bioelement.