Alteration of brain and liver microsomal polyunsaturated fatty acids following dietary vitamin E deficiency

Vitamin E is of importance for several physiological processes, some of which also apply to fish. Here, we conducted an experiment to assess the effect of environmental hypoxia and dietary vitamin E on oxidative status and tissue injury in a bottom dwelling carp,Cirrhinus mrigala(Ham., 1822). The four treatments combined oxygen availability (Normoxia/Hypoxua) and Vitamin E presence/absence. Lipid peroxidation parameters such as thiobarbituric acid reactive substances (TBAR), peroxide value (PV), polyunsaturated fatty acids/saturated fatty acid (PUFA/SFA) ratio, catalase (CAT), superoxide dismutase (SOD) and erythrocyte fragility were assessed. The results indicate that exposure to hypoxia elevates these parameters. However, the supplementation of vitamin E via the diet effectively reduced erythrocyte membrane damage (EF) and myeloperoxidase activity (MPO), which were enhanced by the exposure to hypoxia. Dietary vitamin E also improved antioxidant enzyme status in the hypoxia exposed fish, as indicated by the decreased catalase and superoxide dismutase activities. Vitamin E supplementation also compensated for increased levels of peroxide value, thiobarbituric acid reactive substances, and an increased polyunsaturated fatty acids/saturated fatty acid ratio resulting from the exposure to hypoxia. Overall, it can be concluded that fortification of vitamin E in the diet of this carp species, and possibly other fish that live under hypoxic conditions, can restore the antioxidant status and well-being to some extent.

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Influence of dietary fat source on oxidative stability and fatty acid composition of milk from cows receiving a low or high level of dietary vitamin E

Canadian Journal of Animal Science ◽

10.4141/cjas94-095 ◽

1994 ◽

Vol 74 (4) ◽

pp. 657-664 ◽

Cited By ~ 36

Author(s):

E. Charmley ◽

J. W. G. Nicholson

Keyword(s):

Fatty Acids ◽

Vitamin E ◽

Polyunsaturated Fatty Acids ◽

Soybean Meal ◽

Milk Fat ◽

Latin Square ◽

Tocopheryl Acetate ◽

Dietary Vitamin ◽

Milk Fatty Acids ◽

Fat Supplementation

Fifteen primiparous Holsteins were used in a latin square design with three periods and three treatments to assess the effect of fat source on milk flavour, yield and composition, and composition of milk fat. A basal diet was supplemented with one of three concentrates offered twice daily: soybean meal (no supplemental fat); cracked, micronized soybeans (containing 20 g kg−1 oil); and soybean meal plus CSFA which supplies an amount of fat similar to that of the soybeans. Periods lasted 6 wk, and each cow received 6000 IU dL α-tocopheryl acetate d−1 for the last 2 wk of each period. Measurements of milk yield, composition and flavour were made at the end of weeks 4 and 6 of each period. Feeding CSFA reduced DM intake (P = 0.064), but fat supplemented diets tended to supply more NE1 than the unsupplemented diet (P = 0.085). Yields of milk (P < 0.001), fat (P < 0.001) and energy (P = 0.003) were increased by fat supplementation. Protein yield was reduced (P = 0.003) when CSFA were fed. Soybeans reduced fat concentration in milk, but only before supplemental vitamin E was given. Soybeans increased α-tocopherol output in milk (P < 0.05). Milk from cows fed soybeans was most susceptible to oxidation (P < 0.01). Intensity of oxidized flavour was similar before and during vitamin E supplementation. Fat supplementation reduced the proportion of short- and medium-chain fatty acids (P < 0.001) and increased the proportion of C18 fatty acids in milk (P < 0.001). Soybeans increased the proportion of polyunsaturated fatty acids in milk but CSFA did not. Soybeans can escape biohydrogenation in the rumen and render milk susceptible to oxidation by increasing the proportion of polyunsaturated fatty acids. At the levels fed, vitamin E did not prevent oxidation due to its low transfer to milk. Key words: Oxidized milk, fatty acids, soybeans, tocopherol, dairy cow

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