出生時の normoxia 酸素投与が熱帯の農場条件下での子豚の成長と生存率を向上させる

Neonatal piglet mortality remains a major challenge in hyper-prolific sow herds, particularly under tropical conditions where low ambient oxygen (18-21%) may exacerbate hypoxia during prolonged farrowing. This study evaluated whether restoring normoxia (21% O₂) immediately after birth improved piglet colostrum intake, blood glucose levels, and survival to 3 d. A total of 1837 piglets from 95 sows were weighed at birth and assigned by litter to exposure to either a normoxic chamber (FiO₂ = 0.21) or ambient-air control (FiO₂ = 0.16-0.18) for 15 min post-partum. Piglet colostrum intake, blood glucose content, and survival to 24-h and 3 d were analyzed using mixed-effects models. Compared with controls, oxygen-supplemented piglets showed higher postnatal oxygen saturation (94.2 ± 3.6 vs. 88.1 ± 3.5%), greater colostrum intake (348 ± 263 vs. 320 ± 233 g), higher blood glucose (97.7 ± 13.0 vs. 93.8 ± 13.1 mg/dL), and increased 3-day survival (86.1% vs. 80.8%; p < 0.01). The effect was most pronounced in piglets < 1.0 kg and >1.3 kg, reflecting improved recovery from transient hypoxia. Mean weaning weight increased by 0.3 kg, indicating sustained benefits in early growth. These findings demonstrate that short-term normoxic oxygen supplementation is a practical, cost-effective intervention that enhances growth, metabolic stability, and survival in neonatal piglets under tropical commercial farm conditions.