Effects of iron dosage administered to newborn piglets on hematological measures, preweaning and postweaning growth performance, and postweaning tissue mineral content

Objective: To evaluate the effect of iron dosage given at birth on pig growth performance, the course of the preweaning and postweaning blood profile, and postweaning tissue mineral concentration. Materials and methods: Crossbred pigs (n = 70) were assigned to 1 of 5 iron dosages (0, 50, 100, 200, and 300 mg iron) administered by injection on day 0. Body weight and blood samples were collected at day 0, 1, 2, 3, 4, 6, 8, 11, 17, 22, 23, 24, 25, 29, 38, and 52. All blood samples were analyzed for complete blood count (CBC) profile. On day 22, 38, and 52, tissues from 3 pigs per treatment were obtained for analysis of trace minerals (Fe, Zn, Cu, and Mn). Results: Pigs receiving no iron at birth had the slowest growth and lowest hematological profile demonstrating that iron deficiency anemia (IDA) was induced. Hemoglobin concentrations were increased as early as day 6 and continued to increase until day 17 for the 200 and 300 mg iron treatments. Body weight, other hematological measures, and tissue iron content were greater for pigs that received an iron injection at birth. Implications: Pigs that did not receive an iron injection shortly after birth developed IDA resulting in poor growth, low blood hematological measures, and depleted tissue iron reserves. Supplying an iron injection at birth improved preweaning and postweaning growth performance and CBC profile. The magnitude and timing of peak hematological responses was dose dependent.