Influence of Supplemental Iron Dextran Injections on Hemoglobin Concentrations and Piglet Growth

To prevent iron deficiency anemia, supplemental iron typically is given to piglets within 5 d after birth. Large piglets are at greater risk of iron deficiency than are smaller piglets; however, iron dextran injection protocols are highly variable. The objectives were to determine the within herd prevalence of anemia among piglets, and to evaluate the influence of a supplemental iron dextran injection on growth.

The study (n=436 piglets) was conducted on 5 sow farms and nursery facilities. Two farms injected piglets with 200 mg iron dextran at processing. The third farm used 150 mg iron dextran at the time of processing. Farm 4 used 150 mg iron dextran when pigs were 1 d and 5 d of age. For Farm 5, pigs were injected with iron dextran (150 mg) at processing and on the day prior to weaning. At d 14, 6 piglets/litter were blood sampled and matched by body weight to provide a pair of heavy, medium piglets, and light piglets in each litter. One pig/pair received 200 mg iron dextron (Uniferon®; TMT pigs) immediately after the blood collection. At 3 wk after weaning, all pigs were weighed and blood samples collected. Samples were analyzed for Hb concentrations with a HemacueHB201® instrument. Multiple linear regression models were used for Hb concentration and weight. Since the models suffered from multicollinearity and significant interactions, simple effects of treatment were used for combinations of factors.

Prior to the iron dextran injection at 14 d of age, Hb concentrations were higher (P< .05) in the lighter pigs than in the heavy pigs. At 44 d of age (3 wk after weaning), there were no differences in Hb concentrations between TMT and CON groups. At 44 d of age, differences in BW were similar to those differences at the onset of the study. For Farms 1 and 3, the heavy pigs, treated with iron dextran at 14 d of age, were heavier (P < 0.05) than their control counterparts. The additional iron injection had no effect on growth in Farms 2, 4 and 5.

The heavy pigs had the lowest Hb concentrations at 14 d of age. This inverse relationship, i.e. heavy pigs with low Hb, creates a confounding issue (as seen with interactions) for the evaluation of supplemental iron on pig growth. Pre-planned differences BW continued into the nursery phase of production. The influence on weight gains was not consistent in the 5 farms. It was evident that the BW at 14 d of age had the most significant influence on subsequent BW at 44 d of age. There was considerable variation among pigs (within a weight class) in Hb concentrations. This may reflect shortcomings in injection technique.

Disclosure of Interest: None Declared.