PSIV-14 - Assessing sow and suckling pig hemoglobin status in a single lactation following one or two iron supplementations of piglets in a commercial farm

Abstract: Newborn piglets are typically anemic at birth [defined as blood hemoglobin concentration (Hb) < 10 g/dL] and sow’s milk contains negligible amounts of iron; common commercial practice is one dose of injectable iron in the first week of life. However, a considerable proportion of piglets have low Hb at weaning which may have implications on post-wean performance thus there is interest in additional iron supplementation prior to weaning. The primary objective of this study was to evaluate the impact of one or two iron supplementations on offspring performance. A total of 172 sows (parity 1 to 8) and litters (n = 2,378 piglets) were assigned in a randomized complete block design to Control [piglets received one injectable iron dose (400 mg)], SUPoral (injectable iron as Control plus oral iron supplement at 1oz/litter per day for 8 days before weaning), or SUPinject (injectable iron as Control plus 100 mg 7d before weaning). According to barn stand protocol, the first iron dose was provided to all piglets on day 7 after the initiation of farrowing. Sow Hb status was determined at entry to farrowing house and weaning; -Hb status of all born alive piglets was measured within 28 of birth and at weaning. Analysis of variance compared the effect of iron supplementation, parity, and their interaction on piglet Hb status. Sow Hb at entry (9.3, 10.4, and 9.6 g/dL ± 0.15, respectively) was lower (P < 0.001) for parity 4-8 sows than parity 1, with parity 2-3 intermediate and no difference between parity groups at weaning (9.5 g/dL ± 0.16). Litter size at birth (total or born alive) and preweaning mortality did not differ between treatments. Piglet Hb at birth was not different between treatments; however, 85% of piglets from parity 4-8 sows were deemed anemic at birth compared to 72 and 76% in parity 1 and 2-3 sows, respectively (P < 0.05). Immediately prior to additional iron supplementation, Control piglets had lower (P <.0001) Hb than SUPoral and SUPinject piglets (7.4 vs 8.0 and 8.1 g/dL ± 0.12, respectively). At weaning, there were no differences in piglet Hb by iron supplementation treatments (11.4 g/dL ± 0.07). However, the percentage of piglets within a litter deemed anemic at weaning was greater (30%; P < 0.011) in parity 4-8 sows compared to parity 1 sows at 13%. There was no difference in piglet body weight at weaning between treatment groups or by parity grouping. In this study, additional iron supplementation prior to weaning had minimal impact on piglet iron status or growth. The lower Hb at entry in older sows combined with greater proportion of anemic piglets at birth or weaning suggests greater attention to sow iron intake may be warranted.