Lipidomics-based analysis of the regulatory effects of phytosterol esters on lactation performance and lipid metabolism in Tarim Bactrian camels

Plant sterol esters (PSE) exert beneficial effects on animal product quality, indicating potential as a nutritional intervention strategy. This study investigated dietary PSE supplementation effects on lactation performance and lipid metabolism in Tarim Bactrian camels (Camelus bactrianus), to establish a scientific basis for PSE implementation in Bactrian camel husbandry. Thirty-two mid-lactation female camels were randomly allocated equally among four groups (n=8 per group)：the CON group, basal diet; the L group, basal diet with 200 mg/kg PSE; the M group, basal diet with 400 mg/kg PSE; and the H group, basal diet with 800 mg/kg PSE. Lactation performance in Bactrian camels is strongly correlated with metabolic status. Furthermore, biochemical analysis and lipidomics were performed on serum and milk samples to evaluate associations between lactation performance and metabolic alterations.Analysis of milk composition revealed that the H group exhibited significantly higher milk yield (p = 0.003), lactose yield (p < 0.001), and milk fat yield (p = 0.007) compared to other groups. Cholesterol levels in serum decreased progressively with increasing dietary PSE supplementation (p = 0.017). Conversely, serum urea levels increased dose-dependently of PSE dose (p < 0.001). Compared to the CON group,blood glucose levels were significantly lower in the L group, but significantly higher in the H group (p = 0.026). Lipid metabolomic analysis identified 644 and 257 differential metabolites (DMs) in milk and serum, respectively. Milk DMs were enriched in pathways including EGFR tyrosine kinase inhibitor resistance, MAPK signaling pathway, and ErbB signaling pathway. Serum DMs were predominantly enriched in glycerophospholipid metabolism, arachidonic acid metabolism, and linoleic acid metabolism. Collectively, these findings demonstrate that serum and milk metabolites modulated by PSE intervention significantly influence lactation performance and glucolipid metabolismin Tarim Bactrian camels . Elucidating the specific metabolic alterations is critical for advancing precision livestock farming. Thus, further investigation into the regulatory roles of key metabolites throughcontrolled experimental validation is warranted.