This study investigated the effects of linseed oil (LO) supplementation on conjugated linoleic acid (CLA) biosynthesis in lactating Saanen goats. Goats (DIM = 96 ± 14 days) were divided into control (n = 6) and LO treatment (n = 6) groups. LO supplementation was implemented in both short- and long-term experimental settings. Short-term LO supplementation significantly increased trans-11 vaccenic acid and cis-9,trans-11 CLA in milk fat without affecting lactation performance. Using two-dimensional gel electrophoresis, we identified six upregulated proteins in milk somatic cells, including translocon-associated protein (SSRD), succinyl-CoA ligase (SUCB2), ATP synthase subunit (ATPD), stress-70 protein (GRP75), NADH dehydrogenase (NDUFS2), and cytochrome complex QCR1. Long-term LO supplementation enhanced milk fat content and cis-9,trans-11 CLA levels, while significantly elevating the mRNA expression of stearoyl-CoA desaturase (SCD) and all previously identified proteins-including proteasome 20s subunit alpha 5 (PSMA5). These findings extend beyond the known SCD pathway, revealing novel protein markers and potential mechanisms associated with CLA biosynthesis in mammary tissue and milk somatic cells.
Keywords: conjugated linoleic acid; goat mammary tissue; milk somatic cell; trans-vaccenic acid.