Impact of Iron Supplementation on Growth Performance, Iron Homeostasis and Redox Balance of Suckling Piglets

This study evaluates the effects of intramuscular injection or oral supplementation of iron on the growth performance, iron homeostasis, and redox status of suckling piglets. A total of 94 newborn piglets, selected from 8 healthy sows, were randomly allocated into 4 treatment groups during the lactation period, receiving injections of normal saline without iron (CON, n = 23), intramuscular dextran injection of bound iron at 2 mL (200 mg Fe) on postnatal day 3 (PND 3) (FeDex, n = 24), oral supplementation from PND 2 to 13 with 10 g of FerkoFer^® containing 2.2 g Fe per day (FeOra, n = 23), or both FeDex and FeOra (FeDPO, n = 24). Piglets were weighed individually at birth and PND 21. Blood samples were collected on PNDs 1, 7, 14, and 21. Piglets in the CON group had lower body weight on PND 21 compared with piglets in the FeDex, FeOra, and FeDPO groups (0.46-1.05 kg decrease, <i>p</i> < 0.05), while piglets in the FeDPO group had the highest weaning weight across all groups (<i>p</i> < 0.05). The levels of hemoglobin (HGB) and serum iron (SI) in FeDPO piglets were significantly higher than in all other groups on PNDs 14 and 21 (<i>p</i> < 0.05). Moreover, the red blood cell (RBC) levels in the FeDPO and FeOra piglets were significantly higher than that in FeDex piglets on PND 21 (<i>p</i> < 0.05). In addition, serum superoxide dismutase (SOD) and catalase (CAT) activities in both FeOra and FeDPO piglets were significantly higher than those of piglets in CON and FeDex piglets on PND 21 (<i>p</i> < 0.05), whereas malondialdehyde (MDA) content in FeDex piglets was higher than that in CON piglets (<i>p</i> < 0.05). Collectively, the current results indicate that the combination of intramuscular injection and oral supplementation is a more effective strategy to improve the growth performance of suckling piglets, associated with higher hemoglobin and serum iron levels, as well as the optimal redox status.