Effect of Additional Iron Injection to Suckling Pigs on Hematocrit Level during the Suckling Period

SIMPLE SUMMARY: Piglets are susceptible to iron-deficiency anemia since they are born with low iron reserve and sow milk contains low content of iron. A single iron injection is a common practice in swine industry but may not be sufficient to meet iron requirement during the entire suckling period when pigs are weaned at the age over 21 d. A second iron injection in the suckling period could be a useful way to boost iron status and thereby help to improve oxygen carrying capacity of suckling pigs. However, it has not been demonstrated yet if there is a difference in the effectiveness of second iron injection to piglets weaned at a longer age (approximately 28 d of age) when injected at different doses and when having different hematocrit status at the time of administration. The current study aims at demonstrating the effect of an additional iron injection on hematocrit levels in suckling pigs when different levels of iron were administered to pigs at birth or in the suckling period. The result of current study suggested that the additional iron injection to suckling pigs could increase hematocrit levels. The amount of iron in the first (at birth) and second (before weaning) injections could affect the effectiveness of the second iron injection on blood hematocrit level. ABSTRACT: Two experiments were conducted to evaluate the effects of additional iron injection to suckling piglets on hematocrit level during the suckling period. In Experiment 1, a total of 24 piglets were allotted into 3 treatments within litter based on body weight and sex at d 1 of age. Treatments were: (1) Control: a 200 mg iron-dextran intramuscular injection only at d 0 of experiment (d 1 of age), (2) Iron100: intramuscular iron-dextran injections at d 0 (200 mg iron) and 15 (11 d before weaning) of experiment (100 mg iron), and (3) Iron200: intramuscular iron-dextran injections at d 0 (200 mg iron) and 15 of experiment (200 mg iron). In Experiment 2, a total of 20 piglets were allotted into 2 treatments within litter based on body weight and sex at d 1 to 2 of age. Treatments were: (1) Iron100b: 100 mg iron-dextran intramuscular injection at d 0 of experiment (d 1 to 2 of age), and (2) Iron200b: 200 mg iron-dextran intramuscular injection at d 0 of experiment. An additional 200 mg iron-dextran was injected to all piglets intramuscularly at d 14 of experiment (11 d before weaning). In Experiment 1, there was no difference in hematocrit levels among treatments at d 15 of experiment. Both iron treatments had greater hematocrit levels than the Control treatment at d 22 and 26 of experiment (p < 0.05). The Iron200 treatment had greater hematocrit level at d 26 of experiment (p < 0.05) and tended to have a greater increase of hematocrit levels in d 22 to 26 of experiment (p = 0.09) than the Iron100 treatment. In Experiment 2, the Iron200b treatment had greater hematocrit levels than the Iron100b treatment in d 14 and 25 (p < 0.05) of experiment. Hematocrit level changes tended to be greater in the Iron200b treatment in d 0 to 14 (p = 0.08) of experiment but lower in d 14 to 25 (p < 0.05) of experiment than the Iron100b treatment. The additional iron injection to suckling piglets increased hematocrit levels with greater values at weaning in the higher injection level whereas the increase was greater when the hematocrit level was low at the time of additional injection.