One hundred and eighty 35-day-old piglets (Duroc x Landrace x Yorkshire) weighing 7.8±0.72 kg were blocked based on weight, sex and ancestry and randomly allotted to six dietary treatments, each of which was replicated three times with 10 pigs per replicate. Treatments consisted of: (1) control (no Fe supplementation); (2) 30mg Fe from Fe-Gly/kg diet; (3) 60mg Fe from Fe-Gly/kg diet; (4) 90mg Fe from Fe-Gly/kg diet; (5) 120mg Fe from Fe-Gly/kg diet; (6) positive control, 120mg Fe from ferrous sulphate (FeSO4)/kg diet.
Feeding the diets containing Fe-Gly for 40 days resulted in an increased Fe concentration in heart (P<0.05), liver (P<0.05), kidney (P<0.05), spleen (P<0.05) and feces (P<0.01). There were linear responses to the addition of Fe-Gly from 0 to 120mg Fe/kg Fe on concentration in the liver and kidney. FeSO4 also enhanced heart, liver, spleen and faecal Fe concentration (P<0.05) or P<0.01) compared with the control. Spleen Fe concentration was enhanced (P=0.01) and fecal Fe concentration was little reduced (P=0.09) when pigs were fed with 120mg Fe as Fe-Gly/kg compared with 120mg Fe as FeSO4/kg. Linear responses to the addition of Fe-Glywere observed on catalase and succinate dehydrogenase (SDH) activities. 90mg Fe as Fe-Gly/kg increased superoxide dismutase (SOD) (P=0.02) and SDH (P=0.03) activity compared with the negative control. However, there were no significant differences in pancreas mineral concentration, fecal Cu, Zn and Mn concentration and liver xanthine oxidase activities among the treatments (P>0.05).
It is concluded that supplementation with Fe-Gly could improve iron tissue storage and antioxidant enzyme activities, and also could increase Zinc retention in liver and kidney in weanling pig. Additionally, a reduction in faecal Fe concentrations could be found when pigs were fed diets containing Fe as Fe-Gly compared to FeSO4.
J Feng, WQ Ma, ZR Xu, JX He, YZ Wang, JX Liu, 2009. Animal Feed Science and Technology. 150: 106–113.