Effect of conjugated linoleic acid and acetate on milk fat synthesis and adipose lipogenesis in lactating dairy cows

Abstract

During biohydrogenation-induced milk fat depression (MFD), nutrients are spared from milk fat synthesis and are available for other metabolic uses. Acetate is the major carbon source spared and it may increase lipid synthesis in adipose tissue during MFD. The objective of this study was to compare the effect of trans-10,cis-12 conjugated linoleic acid (CLA) and the amount of acetate spared during CLA-induced MFD on adipose tissue lipogenesis. Nine multiparous, lactating, ruminally cannulated Holstein cows (244 ± 107 d in milk; 25 ± 8.4 kg of milk/d; mean ± standard deviation) were randomly assigned to treatments in a 3 × 3 Latin square design. Experimental periods were 4 d followed by a 10-d washout. Treatments were control (CON), ruminal infusion of acetate (AC; continuous infusion of 7 mol/d adjusted to pH 6.1 with sodium hydroxide), or abomasal infusion of CLA (10 g/d of both trans-10,cis-12 CLA and cis-9,trans-11 CLA). Dry matter intake, milk yield, and milk protein yield and percentage were not affected by treatments. Compared with CON, milk fat yield decreased 23% and fat percent decreased 28% in CLA, and milk fat yield increased 20% in AC. Concentration and yield of milk de novo synthesized fatty acids (<C16) were reduced and concentration of preformed fatty acids (>C16) was increased by CLA, compared with CON. Yield of de novo synthesized fatty acids and palmitic acid was increased by AC, compared with CON. Lipogenesis capacity of adipose tissue explants was decreased 72% by CLA, but was not affected by AC. Acetate oxidation by adipose explants was not affected by treatments. Treatments had no effect on expression of key lipogenic factors, lipogenic enzymes, and leptin; however, expression of fatty acid binding protein 4 was reduced in CLA compared with CON. Additionally, hormone-sensitive lipase and perilipin 1 were decreased by CLA and acetate. Plasma glucose and glucagon concentrations were not affected by treatments; however, CLA increased nonesterified fatty acids 17.7%, β-hydroxybutyrate 16.1%, and insulin 27.8% compared with CON, and AC increased plasma β-hydroxybutyrate 18%. In conclusion, during CLA-induced MFD in low-producing cow adipose tissue was sensitive to the anti-lipogenic effects of CLA, while spared acetate did not stimulate adipose lipogenesis. However, acetate may play an important role in stimulating lipogenesis and improving energy status in the mammary gland under normal conditions.

Regulation of Nutritional Metabolism in Different Perinatal Period of Does: Energy Metabolism Efficiency, Lipid Metabolism, Oxidative Stress and Liver Metabolomics Profile in Response to Nicotinamide Supplementation

“…For ruminant, the acetic acid is the main precursor for de novo synthesis of fatty acid in mammary gland, and provides the majority of the carbon. The milk fat yield was increased by 20% when the acetate was ruminal infused to lactating dairy cows, and the de novo synthesized fatty acids and palmitic acid were also increased in milk [16]. In this study, however, the milk fat was not affected by the acetic acid that tended to be decreased [8].…”

Altering the ratio of dietary C16:0 and cis-9 C18:1 interacts with production level in dairy cows: Effects on production responses and energy partitioning

“…This is likely associated with repartitioning of energy toward body fat reserves. Recently, Urrutia and Harvatine (2017) observed reduced lipogenic capacity of adipose tissue explants without changes in gene expression of key lipogenic enzymes during 4 d of trans-10,cis-12 C18:2 infusion. In our study, we did not detect levels of trans-10,cis-12 C18:2 in milk fat of most of our samples, but it is important to consider that other FA produced as intermediates in rumen biohydrogenation have been shown to reduce milk fat (Bauman et al, 2011) and potentially may be involved with energy partitioning.…”

The Effect of CLA-Rich Isomerized Poppy Seed Oil on the Fat Level and Fatty Acid Profile of Cow and Sheep Milk

“…Baumgart et al [42] indicated that abomasal infusion of 3.5, 7, and 14 g/d of trans-10,cis-12 CLA in cows for five days decreased milk fat concentration by 24%, 37%, and 46%, respectively, while both isomers trans-10,cis-12 and cis-9,trans-11 CLA decreased milk fat concentration by 28%, 40.8%, and 38.6%-58.1%, respectively, in the studies by Urrutia and Harvatine [20], Vyas et al [43], and Haubold et al [7]. In the experiment by Dohme-Meier and Bee [44], the supplementation of unprotected CLA decreased fat content in cow milk by 53.8%.…”

“…Fish oil is more effective than plant oils for enhancing milk fat CLA content [16,17] and these responses can be further increased when fish oil is fed in combination with supplements rich in linoleic acid (LA) or CLA [18,19]. In the case of commercial preparations containing synthetically or microbiologically produced CLA [6,20], high prices limit their widespread use.…”