Effect of supplementation of the maternal diet with fish oil or linseed oil on fatty-acid composition and expression of Δ5- and Δ6-desaturase in tissues of female piglets.

The present study investigated whether enrichment of the pig maternal diet with n-3 polyunsaturated fatty acids (PUFA) affects the fatty-acid composition of female piglets via enhancing of expression of the lipogenic enzymes Δ5-desaturase (Δ5d) and Δ6-desaturase (Δ6d). The sows (50% Landrace × 50% Large White) were fed a control diet or one of the experimental diets starting at day 45 in gestation. The experimental diets were supplemented either with linseed oil or fish oil, whereas the control diet contained palm oil. Expression of Δ5d and Δ6d, and fatty-acid composition was determined by Western blotting and gas-liquid chromatography, respectively, in muscle, subcutaneous adipose tissue and liver. The highest Δ5d protein expression was observed in the piglets' muscle, followed by subcutaneous adipose tissue, with the lowest level in the liver. Expression of Δ6d in the piglets' tissues followed an opposite pattern, and was highest in the liver, followed by subcutaneous adipose tissue, with the lowest level in muscle. Supplementation of the maternal diet with fish oil or linseed oil increased the level of n-3 PUFA of the piglets in a tissue-specific manner. The response of Δ6d and Δ5d protein expression in female piglets, with average birth weight 2.4 kg, to the dietary manipulation was also tissue-specific. It is suggested that the increase in n-3 PUFA content in the progeny was related, at least partially, to the activation of Δ6d and Δ5d expression.