Effect of dietary n−6 and n−3 polyunsaturated fatty acids on peroxidizability of lipoproteins in steers

Abstract

The susceptibility of major plasma lipoproteins to lipoperoxidation was studied in relation to the FA composition of their neutral and polar lipids in steers given PUFA-rich diets. Two trials used, respectively, 18 ("sunflower" experiment, S) or 24 ("linseed" experiment, L) crossbred Salers x Charolais steers. Each involved three dietary treatments over a 70-d period: a control diet (CS or CL diets) consisting of hay and concentrate, or the same diet supplemented with oilseeds (4% diet dry matter) fed either as seeds (SS or LS diets) or continuously infused into the duodenum (ISO or ILO diets). Compared with control diets, ISO and ILO treatments tended to decrease the resistance time of LDL and HDL classes to peroxidation, mainly owing to the enrichment of their polar and neutral lipids with PUFA. With diets SS and LS, sensitivity of major lipoprotein classes (LDL, light and heavy HDL) was not affected because ruminal hydrogenation of dietary PUFA decreased their incorporation into lipoparticles. ISO and ILO treatments induced a more important production of conjugated dienes and hydroperoxides generated by peroxidation in the three lipoprotein classes due to the higher amounts of PUFA esterified in lipids of the core and the hydrophilic envelope of particles. The production of malondialdehyde (MDA) increased in steers fed linseed supplements, indicating that MDA production did not occur with linoleic acid provided by sunflower oil supplements. Thus, plasma peroxidation of PUFA generates toxic products in steers fed diets supplemented with PUFA and can be deleterious for the health of the animal during long-term treatment.

Amounts of malondialdehyde do not accurately represent the real oxidative level of all vegetable oils: a kinetic study of malondialdehyde formation

“…The result was related to the fatty acid composition of PO and CLO. To the best of our knowledge, the formation of MDA is closely related to the oxidation of n‐3 and n‐6 PUFA (Scislowski et al ., ; Viau et al ., ). As shown in Table , PO and CLO possessed rather low PUFA levels (8.40% and 7.16% respectively).…”

Supplementation of herbal plants differently modulated metabolic profile, insulin sensitivity, and oxidative stress in transition dairy cows fed various extruded oil seeds

“…PREVET (2014), http://dx.doi.org/10.1016/j.prevetmed.2014.10.013 LS-based diet might be responsible for observing higher oxidative stress symptoms in these cows (Castillo et al, 2003). Also, Scislowski et al (2005) reported that steers receiving duodenal infusion of linseed oil (rich in n-3 FA) were more susceptible to peroxidation than those receiving sunflower oil (rich in n-6 FA). But contrary to our results, they showed that feeding extruded linseed did not induced oxidative stress compared to extruded sunflower seed probably due to extensive ruminal biohydrogenation of PUFA.…”

“…However, enriching diets with omega-3-rich FA (n-3 FAs), such as by supplementing linseed, may concurrently predispose cows to experience more symptoms of oxidative stress and subsequently disturb metabolic homeostasis (Gobert et al, 2009). Some researchers reported that n-3 FA supplementation to fattening steers (Scislowski et al, 2005) or rabbits (Tres et al, 2009) led to greater oxidative stress than omega-6 FA (n-6 FA) supplementation, but the effects of different FA on oxidative status of transition dairy cows that normally experience physiologic oxidative stress remains unclear (Turk et al, 2008).…”

Effect of soya bean and fish oil inclusion in diets on milk and plasma enzymes from sheep and goat related to oxidation

“…In addition, the use of soya bean oil as a possible dietary source to improve the oxidative status of ruminants has been proposed by Scislowski et al. (). Positive impact on the antioxidant defence system may also be observed with the fish oil too, because its inclusion in the diets of rabbits (Hsu et al., ) and rats/hamsters (Erdogan et al., ; Muga and Chao, ) inhibited the oxidative stress and prevented the formation of free radicals.…”

“…Oxidative stress in ruminants occurs not only during periparturient period or heat stress but also when they receive diets rich in PUFA (Scislowski et al., ,b). Although dietary PUFAs are subjected to ruminal biohydrogenation, some of them escape from this process.…”