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.

Effect of rearing system (mountain pasture vs. indoor) of Simmental cows on milk composition and Montasio cheese characteristics

“…Despite part of C16 : 0 and, to lesser extend to C14 : 0, can derived from circulating lipids, short and medium fatty acid can be used to evaluated the mammary de novo FA synthesis (Glasser et al 2005). In our trial, higher level of dietary C18 : 3 n -3 and subsequent higher mammary uptake of this FA could have induced an inhibition effect on FA synthesis in agreement with the findings of Yang et al (2012).…”

Invited review: Nitrogen in ruminant nutrition: A review of measurement techniques

“…Emery et al (1965) found no difference in the concentrations of glucose and acetate in arterial and venous coccygeal blood. This premise has been accepted in studies on mammary gland metabolism of AA (Lykos and Varga, 1997;Doepel and Lapierre, 2010) and fatty acids (Yang et al, 2012). Moorby et al (2002) reported that although concentrations of some AA were slightly different between coccygeal arterial and coccygeal venous blood, the differences were not significant.…”

Effectiveness of rubber seed oil and flaxseed oil to enhance the α-linolenic acid content in milk from dairy cows

“…This result is in agreement with Zheng et al (2005), who reported that the concentration of C14:0 and C16:0 in milk fat was significantly lower in response to added vegetable oils. Moallem et al (2012) and Yang et al (2012) also showed a strong negative correlation between ALA, short-chain, and medium-chain fatty acids in cow milk fat when flaxseed oil and ALA were infused into the digestive tract. Similarly, Bu et al (2007) reported that the proportion of short-chain and medium-chain fatty acids (C10:0, C12:0, C14:0, and C16:0) was lower in milk from cows that were given soybean oil or flaxseed oil at 4% of the diet DM compared with CON group.…”