Effects of iron glycine chelate on growth, haematological and immunological characteristics in weanling pigs

The study was conducted to determine the effects of iron glycine chelate (Fe-Gly) on growth, haematological and immunological characteristics in weanling pigs. One hundred and eighty pigs (initial weight of 7.81 ± 0.72 kg) were allotted to six treatments based on live weight and litter origin. Treatments consisted of: (1) control (no Fe supplementation); (2) 30 mg Fe/kg diet from Fe-Gly; (3) 60 mg Fe/kg diet from Fe-Gly; (4) 90 mg Fe/kg diet from Fe-Gly; (5) 120 mg Fe/kg diet from Fe-Gly; (6) positive control, 120 mg Fe/kg diet from ferrous sulphate (FeSO4). After 40-day feeding trial, the results showed that compared with the control, there was a linear response to the addition of Fe-Gly from 0 to 120 mg/kg Fe, with the greatest ADG (P=0.04) observed in the pigs fed 90 mg/kg Fe. The haemoglobin, Fe concentration and pack cell volume in blood and thymus gland index increased with the increasing levels of Fe as Fe-Gly. One hundred and twenty milligrams per kilogram Fe as FeSO4 also enhanced plasma Fe concentration (P=0.001) and thymus gland index compared with the control. Whole blood lymphocytes had a higher proliferative response to ConA (P<0.05) when pigs were fed with 90 mg/kg Fe as Fe-Gly. No significant response to LPS could be found. There were no significant differences on feed gain ratio, spleen and mesenteric lymphocyte node index, plasma immunoglobulin (IgA, IgG and IgM) contents between the treatments.