Abstract: [Object] This study was conducted to research the effects of dietary supplementation with vegetable oilseeds on bovine milk quality. [Method] Forty Chinese holstein dairy cows were arranged following treatments ( eg. control, and whole full fat soybean, mix-oilseeds with whole cottonseed and soybean and expand soybean, D expand soybean) with a factor completely randomized block, and what change do the fatty acids improve in bovine milk. [Result] CLA percent is the highest in the expand soybean group(P＜0.05). The fatty acids content of high inductive cholesterol disease was decreased with oilseeds supplementation(P＜0.05).[Conclusion] Bovine milk quality was improved with oilseed supplementation, and △9-desatuase activity is relative to ratio of c9t11CLA and t11C18:1 than others.

Key words: dairy cattle, vegetable oilseed, conjugated linoleic acid, bovine milk-fatty acids