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.
Keywords: additional injection; blood; hematocrit; iron; suckling piglets.