title: Duodenal infusion of α-linolenic acid affects fatty acid metabolism in the mammary gland of lactating dairy cows.
abstract: Increasing the concentration of α-linolenic acid (LNA; 18:3 cis-9,cis-12,cis-15) in blood might affect fatty acid (FA) metabolism in the mammary gland of dairy cows. The objective was to determine the effects of different arterial concentrations of 18:3 cis-9,cis-12,cis-15 (18:3n-3) achieved via duodenal infusions with LNA on mammary uptake [assessed via arterial-rectificative venous concentration (AC-RVC) differences], synthesis of FA, and mammary gland FA balance in lactating dairy cows. Four primiparous lactating Chinese Holstein cows fitted with duodenal cannulas were administered 2 treatments in a crossover design: LNA-rich FA infusion at varying concentrations (0, 100, 200, and 300 g/d) versus basal infusate control. Arterial concentration of 18:3n-3 increased quadratically (29.24, 134.1, 218.3, and 219.3mg/L of plasma) as LNA infusion levels increased from 0 to 300 g/d. The mammary extraction rate and uptake of 18:3n-3 increased linearly as LNA infusion increased. The AC-RVC difference of total FA and 18:3n-3 increased more rapidly than arterial concentrations with all treatments. Increasing LNA infusion increased linearly the balance of 10:0 and 12:0, whereas it decreased linearly the 14:1 and 15:0 balances. Increasing arterial concentration of 18:3n-3 affects uptake and synthesis of FA in the mammary gland of lactating dairy cows. It is also suggested that the use of AC-RVC difference maybe an acceptable way to investigate mammary gland uptake and synthesis of FA.
authors.affiliation: State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, P. R. China.
authors.forename: G
authors.initials: G
authors.lastname: Yang
authors.forename: D P
authors.initials: DP
authors.lastname: Bu
authors.forename: J Q
authors.initials: JQ
authors.lastname: Wang
authors.lastname: Khas-Erdene
authors.forename: L Y
authors.initials: LY
authors.lastname: Zhou
authors.forename: J J
authors.initials: JJ
authors.lastname: Loor
mesh_terms: D000818:Animals; D002417:Cattle; D004305:Dose-Response Relationship, Drug; D004386:Duodenum; D005227:Fatty Acids / Q000032:analysis / Q000097:blood / Q000378:metabolism*; D005260:Female; D007263:Infusions, Parenteral / Q000662:veterinary; D007774:Lactation / Q000187:drug effects* / Q000378:metabolism; D008321:Mammary Glands, Animal / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D008892:Milk / Q000737:chemistry / Q000378:metabolism; D017962:alpha-Linolenic Acid / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D005227:Fatty Acids; D017962:alpha-Linolenic Acid