Maternal bis-glycinate bound zinc supplementation alters sow performance and milk metabolomic-lipidomic profiles and mitigates piglet diarrhea

Dietary zinc supplementation to piglets reduces diarrhea and improves growth, yet the effects of maternal zinc supplementation on milk and subsequent piglet performance remain unclear. This study evaluated the impact of maternal zinc supplementation on sow, piglet, and lactation performances. Thirty-six crossbred sows were randomized to CON (standard diet; n = 18) or TRT (standard diet supplemented with 1 g/sow/day of bis-glycinate bound zinc; n = 18) from day 85 of gestation to day 21 of lactation. Sow and piglet performance were recorded. Blood was collected at farrowing to determine serum malondialdehyde (MDA). Colostrum and milk (on days 3 and 10 of lactation) were analyzed for metabolomics and lipidomic profiles. No difference was observed in total number of piglets born, but the percentage of mummified fetuses was higher in TRT than in CON sows (P = 0.030). The TRT sows exhibited greater relative backfat thickness loss during lactation (P = 0.024) and higher serum MDA at farrowing (P = 0.033). Piglets nursed by TRT sows tended toward higher colostrum intake (P = 0.056), higher weight on day 21 (P = 0.116), and lower diarrhea incidence on days 2, 4, 5, 15, and 21 (P P = 0.023) and total solids (P = 0.014), while lower lactose (P = 0.028). Metabolomic and lipidomic analyses of mature milk revealed significantly higher concentrations of O-acetylcarnitine, O-acetylcholine, sn‑glycero-3-phosphocholine, creatine, uridine monophosphate, citrate, dimethylamine, arachidic acid, linolelaidic acid, eicosadienoic acid, and arachidonic acid in TRT. These compounds indicate shifts in energy and lipid metabolism and were positively associated with piglet growth. In conclusion, maternal bis-glycinate bound zinc supplementation was associated with changes in backfat thickness mobilization during lactation, and alterations in milk composition, thereby improving piglet performance.