A Pilot Study of Uterine NAMPT/Visfatin and SPP1 Expression in Cows Under Progesterone-Dominated Reproductive Conditions from Intensive and Extensive Production

Uterine physiology may differ among cattle managed under different farming systems. This pilot study evaluated uterine NAMPT/visfatin and SPP1/osteopontin in pregnant and luteal-phase non-pregnant cattle from one intensive beef farm (INT; n = 7; nulliparous heifers aged 14–18 months, crossbred with a predominant Limousin genetic background) and one extensive farm (EXT; n = 6; Lidia cows aged 28–34 months). Formalin-fixed paraffin-embedded uterine tissues were analyzed by RT-qPCR and immunohistochemistry. Visfatin immunoreactivity was mainly localized in the luminal epithelium and uterine glands. NAMPT expression was higher in the INT cohort than in the EXT cohort (0.6331 ± 0.0855 vs. 0.3632 ± 0.0395; p = 0.0200), whereas SPP1 expression did not differ between cohorts (0.2056 ± 0.0661 vs. 0.1806 ± 0.0562; p = 0.7786). Visfatin immunostaining scores were significantly higher in INT than EXT cows in the secretory adenomeres (median [IQR]: 2.37 [2.15–2.52] vs. 1.48 [1.38–1.77]; p = 0.0012), whereas no significant difference was detected in the combined luminal epithelium/glandular duct compartment (p = 0.4639). Because age, breed, and farm of origin were confounded with management system, these findings should be interpreted as exploratory between-cohort associations.