RT Journal Article T1 Salivary stress biomarkers are increased, independently of maternal welfare status, in lactating Iberian piglets with lower postnatal growth A1 Yeste-Vizcaino, Natalia A1 Isabel Redondo, Beatriz A1 Cerón, José Joaquín A1 Muñoz-Prieto, Alberto A1 Gonzalez-Bulnes, Antonio AB Iberian pigs represent a small but economically significant segment of the Spanish swine sector, valued for the high quality of their products and the strong welfare-friendly image associated with their production systems. As management practices increasingly transition toward more intensive housing, reliable assessment of stress and welfare becomes essential. This study presents the first comprehensive characterization of salivary stress biomarkers—cortisol, α-amylase (sAA), butyrylcholinesterase (BChE), and total esterase activity (TEA)—in 68 Iberian sows across key reproductive stages (early, mid-, and late- gestation; mid-lactation; and weaning) and their relationship with piglet health and performance. Sows showed the highest biomarker levels early in gestation, with values decreasing as pregnancy and lactation progressed. Handling-intensive events elicited pronounced stress responses, especially in primiparous sows. No associations were detected between salivary biomarkers and sow body weight or back-fat depth. Piglets exhibited higher biomarker values at weaning than sows, reflecting acute handling stress. Sex and maternal parity did not significantly affect piglet biomarkers. Lower postnatal body weight was associated with elevated cortisol, sAA, and TEA, indicating increased physiological stress in lighter piglets. These findings validate salivary biomarkers as practical, non-invasive indicators of welfare in Iberian pigs and provide essential reference patterns to support improved management and welfare assessment in this breed PB Frontiers Media YR 2026 FD 2026 LK https://hdl.handle.net/20.500.14352/134114 UL https://hdl.handle.net/20.500.14352/134114 LA eng NO Yeste-Vizcaino, N., Isabel, B., Cerón, J. J., Muñoz-Prieto, A., & Gonzalez-Bulnes, A. (2026). Salivary stress biomarkers are increased, independently of maternal welfare status, in lactating Iberian piglets with lower postnatal growth. Frontiers in veterinary science, 13, 1772189. https://doi.org/10.3389/fvets.2026.1772189 NO Author contributionsNY-V: Formal analysis, Investigation, Methodology, Writing – original draft. BI: Writing – review & editing. JJC: Methodology, Writing – review & editing. AM-P: Methodology, Writing – review & editing. AG-B: Writing – original draft. DS Docta Complutense RD 10 abr 2026