Heme and Non-heme Iron on Growth Performances, Blood Parameters, Tissue Mineral Concentration, and Intestinal Morphology of Weanling Pigs

This experiment was conducted to evaluate the effects of heme and non-heme iron sources on growth performances, blood parameters, tissue mineral concentration, and intestinal morphology in weanling pigs. At 25days of age, 32 newly weaned piglets (DurocxLandracexYorkshire; 8.66 +/- 0.59kg) were allocated to one of the following dietary treatments: control group (basal diet with no extra iron addition), FeSO4 group (basal diet +100mg Fe/kg as FeSO4), Fe-Gly group (basal diet +100mg Fe/kg as Fe-Gly), and Heme group (basal diet +100mg Fe/kg as Heme). Each treatment had eight replicates and one pig per replicate. The experiment lasted for 28days. The results showed that compared with basal diet, supplement with 100mg/kg iron can increase ADG of the piglets, especially in the late experiment period (15 similar to 28days). Heme significantly increased the a* value of longissimus dorsi muscle of piglets when compared with other iron sources (P<0.05). The iron supplementations had no significant effect on hematological parameters, while Fe-Gly and heme increased pigs' serum iron content on day 28 when compared with FeSO4 and basal diet (P<0.05). The liver iron deposition in pigs fed Fe-Gly and heme was also higher than those fed FeSO4 or basal diet (P<0.05). Besides, diet supplement with iron significantly increased villus height (P<0.05) in duodenum and it had tendency to increase villus height and crypt depth ratio in duodenum (P=0.095). In conclusion, iron supplementation in diets can improve piglet's body iron state and intestinal development, but Fe-Gly and heme exhibited better bioavailability than traditional additive of FeSO4.