An investigation of iron deficiency and anemia in piglets and the effect of iron status at weaning on post-weaning performance

Abstract

Objectives: To determine iron status of pigs at weaning and its effects on post-weaning performance, and to determine whether high concentrations of zinc oxide (ZnO) in feed are associated with postweaning anemia. Materials and methods: A small, medium, and large piglet (N = 1095) were selected per litter 1 to 2 days before weaning from 20 Ontario (Canada) swine farms. Serum and whole blood samples and body weights were collected. Three weeks later, a second body weight and blood sample were collected from the same pigs. Hemoglobin (Hb) and other blood parameters were analyzed to assess iron status and associations with post-weaning performance. Iron supplementation protocols and ZnO concentrations in nursery feed were collected. Results: Anemic and iron-deficient pigs presented at weaning on most participating farms. Pigs that had been anemic at weaning were 0.82 kg lighter 3 weeks post weaning than piglets that had normal Hb values at weaning (P < .05). Larger piglets at weaning had lower red cell parameters and serum iron, and higher total iron binding capacity, than smaller piglets (all P < .05). More pigs were anemic 3 weeks post weaning than at weaning (P < .05), and prevalence of anemia was associated with high ZnO concentrations (P < .05). Implications: Iron supplementation protocols used in the study herds were inadequate to prevent iron deficiency, particularly in the largest pigs. Anemic pigs at weaning have slower growth rates in the nursery. Consumption of nursery starter feeds containing high concentrations of ZnO is associated with post-weaning anemia.