Effect of extensive feeding on α-tocopherol concentration and oxidative stability of muscle microsomes from Iberian pigs

Abstract

The effect of extensive feeding, confinement and diet supplementation with a-tocopheryl acetate (100 mg/kg) on the fatty acid composition and tocopherol concentration of microsome extracts and their susceptibility to oxidation was studied in Iberian pigs. The diet of pigs raised extensively was mostly composed of acorn and grass. The a-tocopherol contents of acorn and grass were 20 and 171 mg/kg dry matter, respectively. Microsomal fatty acid composition showed no differences among groups. Pigs feeding extensively had a higher concentration of a-tocopherol in muscle and microsomes than pigs given mixed diet with the basal level of a-tocopheryl acetate (P < 0·05) but lower values than pigs given supplementary levels (100 mg/kg) (P < 0·05). Microsomal fractions from pigs given mixed diet with a basal level of a-tocopheryl acetate were significantly more susceptible to iron-induced lipid oxidation than extract from pigs given diets containing a supplementary level (P < 0·05). Microsomal extracts from pigs feeding extensively had the lowest oxidation rate (P < 0·05), suggesting that other dietary constituents may play a role in the stabilization of microsomal lipids.

Body composition and blood parameters of newborn piglets from Alentejano and conventional (Large White × Landrace) genotype

“…Acorns contain high level of C18:1 (higher than 60% of fatty acids, Rey et al, 1997). This would suggest that some dietary fatty acids could cross the porcine placenta, in agreement with Gerfault et al (1999) and Rooke et al (2001).…”

Effect of Iberian pig feeding system on tissue fatty-acid composition and backfat rheological properties

“…These results are in accordance with Rey et al (2006), but Cava et al (1997) and Daza et al (2005a) observed a higher C18 :1 n-9 proportion in longissimus dorsi intramuscular PL in Iberian pigs raised under free-range conditions than in those fed a formulated diet in confinement. However, Rey et al (1997) were unable to detect differences in C18:1 n-9, C18:2 n-6, n-6 and n-3 proportions in microsome extracts from longissimus dorsi muscle when free-range and mixed diet fed pigs were compared. 1,2,3,4,5,6 -explanation see Table 2 The liver fat (LF) percentages were 6.…”

The effect of immunocastration and a diet based on granulated barley on growth performance and carcass, meat and fat quality in heavy gilts

“…Pentadecenoic acid (C15:1) (Sigma, Alcobendas, Madrid, Spain) was used as internal standard. Previously, methylated FA samples were identified according to Rey et al (1997) using a gas chromatograph (Model HP6890; Hewlett Packard Co., Avondale, PA, USA) and a 30 m × 0.32 mm × 0.25 μm cross-linked polyethylene glycol capillary column (Hewlett Packard Innowax, Avondale, PA, USA). A temperature programme of 170°C to 245°C was used.…”