Time-Resolved Transcriptomic Analysis of Mammary Ductal Development, Lactation Function Activation, and Glandular Involution in Sows

Samples were obtained at five critical physiological stages: mid-gestation (Day 70), late gestation (Day 110), early lactation (Day 2 postpartum), peak lactation (Day 10 postpartum), and early involution (Day 2 post-weaning), with six biological replicates per stage.

Parenchymal mammary tissue (0.5–1 cm³) was excised from a defined location below the third pair of teats and rapidly snap-frozen in liquid nitrogen for RNA preservation. All instruments were treated with RNase inhibitors to ensure RNA integrity. The collected samples were stored at –80°C for subsequent total RNA extraction and transcriptome sequencing, providing a valuable resource for elucidating molecular mechanisms underlying mammary gland remodeling and lactation regulation in sows.