High dietary vitamin A interferes with tissue α-tocopherol concentrations in fattening pigs: a study that examines administration and withdrawal times

Abstract

This study aimed to assess the interaction between different dietary vitamin A (dVitA) levels and the same concentration of vitamin E (100 IU all-rac-a-tocopheryl acetate/kg feed) in growing-finishing pigs. In the first experiment, two fat sources 3 two dVitA levels (0 v. 100 000 IU) were used. The supplementation of 100 000 IU dVitA induced a range of 5.13 to 30.03 mg retinol/g liver, 62.78 to 426.88 mg retinol palmitate/g liver, and 0.60 to 1.96 mg retinol/g fat. Dietary fat did not affect retinol or retinyl palmitate deposition in pigs. The high concentration of dVitA produced lower fat and liver a-tocopherol concentrations, and increased susceptibility of muscle tissue to oxidation. A second experiment was carried out to study the retinol and a-tocopherol retention at different withdrawal times prior to slaughter (two dVitA levels; 0 v. 100 000 IU). A high dose of 100 000 IU vitamin A during a short 2-week period was enough to induce a-tocopherol depletion in liver and fat to a similar extent as when 100 000 IU were administered during the whole fattening. Muscle, fat and liver a-tocopherol concentrations were not affected by dVitA in the 1300-13 000 IU/kg range, but liver a-tocopherol concentration was higher when vitamin A was removed from the vitamin mix 5 weeks prior to slaughter (experiment 3).

Carotenoid intake and SCD genotype exert complementary effects over fat content and fatty acid composition in Duroc pigs1

“…The carotenoid-rich diet (C+) increased the content of retinoids in the liver, in line with reported trials supplying different amounts of commercial vitamin A (Olivares et al, 2009c(Olivares et al, , 2011Tous et al, 2014). In the body, vitamin A is found in 3 main circulating vitamers differing in their oxidation state (Bonet et al, 2003): the hydroxyl form (retinol), the aldehyde form (retinal), and the carboxylic acid form (retinoic acid).…”

“…Our experiment indicates that restricted PVA diets (such as C-) promote IMF deposition with no change in production traits, in line with previous findings in cattle (Siebert et al, 2006;Gorocica-Buenfil et al, 2007;Kruk et al, 2008;Pickworth et al, 2012) and pigs Olivares et al, 2011;Ayuso et al, 2015a,b). Nonetheless, in pigs, the favorable effect of restricted vitamin A intake on IMF is less consistent across genetic types (Olivares et al, 2009b) and more variable with respect to the intensity and duration of the restriction period (Olivares et al, 2009c(Olivares et al, , 2011 and the target muscle (Ayuso et al, 2015a). Moreover, this effect was not replicated in all experiments (Olivares et al, 2009a;Tous et al, 2014).…”

The potential for increasing the concentrations of micro-nutrients relevant to human nutrition in meat, milk and eggs

“…Arnett et al 2009). Muscle retinol was increased by dietary supplementation in chickens (from 90 to 180 μg/kg; Jensen et al 1998) and in pigs (from 30 to 60 μg/kg; Olivares et al 2009), but these were 1000fold less than increases in liver retinol (58-190 mg/kg for chicken and 62-430 mg/kg for pig) in the same experiments. Similarly, the net increase in egg retinol on supplementation was substantially greater (250 μg/ kg; Leeson & Caston 2003) than muscle.…”

Ontogeny of Sex-Related Differences in Foetal Developmental Features, Lipid Availability and Fatty Acid Composition

“…Intramuscular fat and liver fat were extracted from 300 mg of lyophilised and homogenised samples using the Ball-mill procedure [86]. Fatty acids in the total lipid extracts were identified and quantified by gas chromatography (HP6890, Hewlett Packard, Avondale, PA, USA) after methylation, as described in [87,88]. Fatty acid methyl esters were fractionated on a cross-linked polyethylene glycol capillary column (30 cm × 0.32 mm × 0.25 μm, Hewlett Packard Innowax) and a temperature gradient from 170 °C to 245 °C.…”