Effects of Dietary Flaxseed Oil Supplementation on Equine Plasma Fatty Acid Concentrations and Whole Blood Platelet Aggregation

Abstract

An 18‐week feeding trial was performed to investigate the effects of an omega‐3 (n‐3) fatty acid‐enriched ration on plasma fatty acid concentrations and platelet aggregation in healthy horses. Flaxseed oil served as the source of the n‐3 fatty acid alpha‐linolenic acid (ALA). Twelve horses were fed dietary maintenance requirements using a complete pelleted ration (80%) and timothy grass hay (20%) for a 2‐week acclimation period before being randomly assigned either to a treatment (group 1) or control (group 2) group. Group 2 horses (n = 6) were fed the diet described in the acclimation period, whereas group 1 horses (n = 6) were fed a 10% flaxseed oil‐enriched complete pellet (80%) and grass hay (20%). Biological samples and physical measurements were collected at one point during the acclimation period (week 0) and every 4 weeks thereafter (weeks 4, 8, 12, and 16). Body weight, CBC (including platelet count), plasma fibrinogen, electrolyte (Na, K, and Cl) concentrations, and biochemical profile enzyme activities (aspartate aminotransferase, alkaline phosphatase, gamma‐glutamyltransferase, and creatine kinase) did not change markedly with diet. Platelet aggregation was not altered by the supplementation of flaxseed oil in these healthy horses, although increases in plasma cis‐polyunsaturated 18‐carbon fatty acids C18:3; n‐3 (ALA) and C18:2; n‐6 (linoleic acid), biologically active C20:5; n‐3 (eicosapentaenoic acid [EPA]), and malondialdehyde (MDA) were evident. There were no marked decreases in C20:4; n‐6 (arachidonic acid [AA]) or increases in C22:6; n‐3 (docosahexaenoic acid [DHA]), signifying that flaxseed oil may have had a high percentage of omega‐6 (n‐6) fatty acids as well as n‐3 fatty acids, and this relatively high n‐6: n‐3 fatty acid ratio may have affected the biochemical effect of n‐3 fatty acids. In healthy horses supplemented with flaxseed oil, platelet aggregation was not altered, which may have been due to the limited biologic effect in healthy subjects or the inability of flaxseed oil to induce the necessary biochemical effect of replacing n‐6 fatty acids with n‐3 types.

Linseed oil supplementation in diet for horses: Effects on palatability and digestibility

“…Equine trials reporting palatability effects of dietary linseed oil are scarce. Some authors did not mention any adverse effect of linseed oil, used as n-3 source, on palatability of the diet Deem Morris et al, 1991;Hansen et al, 2002). Schumacher et al (1997) reported depression, anorexia and possible signs of mild colic at rates of linseed oil incorporation close to 1250 ml/horse, namely, five times higher than those used presently.…”

Dietary supplementation of conjugated linoleic acid in horses increases plasma conjugated linoleic acid and decreases plasma arachidonic acid but does not alter body fat

“…Exercising horses fed fi sh oil for 63 d had no change in C20:4 concentrations by the end of the study (O'Connor et al, 2007). Likewise, horses fed a diet enriched with fl axseed oil showed no differences in C20:4 concentrations compared with the control diet (Hansen et al, 2002). The authors of that study attributed this to the fact that they had an inadequate n-3:n-6 ratio (Hansen et al, 2002).The role of the reduced plasma C20:4 concentrations in this study on PGE2 pathways and effects on FA composition of other tissues remains unclear.…”

“…Recently, because of their putative anti-infl ammatory effects, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) have been supplemented to horses at maintenance (Hansen et al, 2002;Hall et al, 2004;King et al, 2008), exercised horses (O'Connor et al, 2004;Woodward et al, 2007), and horses with osteoarthritis (Manhart et al, 2009). King et al (2008) described the dose-dependent accretion of supplemental DHA and EPA in plasma and subsequent decrease of these fatty acids (FA) in plasma after their removal from the diet.…”

Beneficial effects of alpha linolenic acid rich flaxseed oil on growth performance and hepatic cholesterol metabolism in high fat diet fed rats

“…An increase in the levels of plasma and tissue FFAs in HFD fed rats that might lead to an increase in the synthesis of phospholipids and cholesterol esters (Jayakumar et al, 1991) which are concomitant with the present study. Treatment with FO showed decreased FFA and phospholipid concentration, which might be due to an inhibitory effect of FO on the lipogenic enzymes (Hansen et al, 2002).…”