Abstract Sow anemia is linked to higher stillbirths, piglet losses, and removals, yet data across genetic lines remain limited. This study characterized anemia prevalence and its association with reproductive performance and mortality risk in prolific sows from a high-mortality herd. Two hundred twenty-five Topigs Norsvin (TN) sows (parities 0–6) from a herd with a 52-week sow mortality rate of 19% were sampled between gestation days 85 and 90. Blood hemoglobin (Hb) was measured on-farm using a HemoCue Hb 201+ device from samples obtained via ear vein prick, and sows were classified as non-anemic (Hb ≥ 10 g/dL) or anemic (Hb 10 g/dL). All sows were fed a standard gestation diet formulated to meet or exceed NRC requirements and were managed under a bump-feeding program providing 2.7 kg/day during the last 4 weeks of gestation. Body condition and perineal scores were recorded at the time of sampling. A subset of 30 sows had jugular venous blood collected for metabolite analysis. Reproductive performance data for the current parity were obtained from farm records and sow mortality events were tracked for 180 days. Reproductive performance and sow measurements were analyzed using PROC MIXED (SAS 9.4) with Hb category and parity as fixed effects. Anemia prevalence was evaluated using PROC FREQ with chi-square analysis. A cox proportional hazards model (PROC PHREG) evaluated the association of sow Hb with mortality risk. Anemia prevalence was 36.4% (82/225 sows had Hb 10 g/dL). Anemic sows had higher number of total born (17.15 vs. 16.15; P = 0.073) and liveborn piglets (16.15 vs. 15.32; P = 0.089) than non-anemic sows. However, stillbirth rate was higher in anemic sows (6.55% vs. 4.87%; P = 0.023). Pre-weaning mortality tended to be greater in anemic sows (10.81% vs. 8.43%; P = 0.089), however, there was no difference in number of pigs weaned by anemia status (anemic: 13.74; non-anemic: 13.92, P = 0.735). Of the subset of sows evaluated for serum metabolites, lactate showed a moderate negative association with number born alive (r = –0.49; P = 0.015). Sow mortality tended to be greater in the anemic sows than the non-anemic sows (9.7% vs 4.2%; P = 0.097), with a 1 unit decrease in Hb resulting in a 12% increase in mortality risk (Hazard ratio: 0.88; P = 0.070). In conclusion, anemic sows had larger litters, but this was offset by higher stillbirth rates, greater pre-weaning loss, and increased mortality risk, indicating reduced sow and piglet viability. Managing Hb status in late gestation is critical to support sow health, farrowing outcomes, and long-term retention.
Morse et al. (Wed,) studied this question.