Lipidomic profiling using GC and LC-MS/MS revealed the improved milk quality and lipid composition in dairy cows supplemented with citrus peel extract

[Display omitted] •Milk antioxidant capacity was increased by graded levels of citrus peel addition.•Milk proportions of MUFA and CLA were enhanced by citrus peel extract.•Feeding citrus peel extract increased milk contents of PE and PC. Eight lactating cows were used to determine the effects of citrus peel extract (CPE) on milk performance, antioxidant properties, and milk lipids composition. CPE supplementation up to 150 g/d (CPE150) increased milk yield and the proportions of unsaturated fatty acids of conjugated linoleic acid. CPE with abundant polyphenol and flavonoids can transfer these bioactive substances to mammary gland and improve the antioxidant properties of milk obtained from cows. Lipidomics revealed that 56 lipid species were altered between CON vs CPE150, and there were five key differential metabolic pathways. In particular, milk phosphatidylethanolamine and phosphatidylcholine were significantly increased with dietary CPE supplementation. In summary, our results provide insights into the modifications in the milk components and milk quality of dairy cows received CPE. The inclusion of CPE in the diet of dairy cows may be an effective and natural way to increase the antioxidant amounts and beneficial lipids in milk.