Effect of dietary linoleic acid concentration and vitamin E supplementation on cell desquamation and susceptibility to oxidative damage of pig jejunal mucosa.

Sixty Large White x Great York pigs weighing approximately 60 kg were individually fed on six experimental diets. The experiment was organized in a 3 x 2 factorial arrangement design with three different fat sources and a basal or supplemented (200 mg/kg diet) level of alpha-tocopheryl acetate. All diets contained the same concentration of saturated fatty acids (15 +/- 0.2 g/kg dry matter) but differed in the concentration of C18 : 2 (14 +/- 0.5, 18 +/- 0.4 and 21 +/- 0.6 g/kg) and monounsaturated fatty acids (19 +/- 0.2, 15 +/- 1.2 and 10 +/- 1.3 g/kg). No effect of dietary treatment was observed on weight gain and feed consumption. A histological study of the jejunal mucosa showed lower cell desquamation in groups containing a supplemental level of alpha-tocopheryl acetate (p=0.080). A higher cell desquamation was found in the groups fed diets containing the higher concentration of C18 : 2 (p=0.087). We also observed an interaction effect (p < 0.001) of dietary fat source and vitamin E supplementation on jejunal cell desquamation in which the effect of dietary vitamin E was lower when diets with a low concentration of C18 : 2 were administered. In vitro-induced oxidation of jejunal mucosa homogenates was lower in pigs fed diets supplemented with alpha-tocopheryl acetate (p < 0.002). The dietary concentration of C18 : 2 significantly affected oxidation of pig jejunal mucosa (p < 0.002).