The influence of dietary fatty acids on their metabolism in liver and subcutaneous fat in growing pigs

Abstract

The aim of the study was to determine the influence of fatty acids sources on their metabolism in the liver and subcutaneous fat. Four iso-energetic and iso-protein diets with different ratio of PUFA/SFA and C 18:2 n-6/C 18:3 n-3 obtained by changing part of the diet energy with plant oils (linseed or rapeseed), tallow or fish oil, were given to pigs from 60 to 105 kg body weight (BW). Pigs were slaughtered at 105 kg BW. The content of fatty acids in the liver and subcutaneous fat per 100 g tissue and the activity (index) of Δ4-and Δ9-desaturase and elongase were determined. It was assumed that replacing part of energy of the diet with energy from different fatty acids of dietary oils will differ activity of enzymes in the investigated tissues and allow to determine in which the metabolism is more intense. Replacement of the part of the energy diets with energy from saturated (SFA), monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA), improved those feeds in the quantity/quality of these fatty acids and increased their proportional content, however, more in the subcutaneous fat than in the liver. Kind of diet had no influence on weight and fat content of the investigated tissues. Irrespective of the applied diet, a lower activity of ∆9-desaturase but higher activity of ∆4-desaturase and index of elongation were detected in the liver rather than in the subcutaneous fat. Results showed that they yield of elongation of the carbon chain of fatty acids and transformation of long-chain fatty acids is higher in the liver, however stronger transformations of SFA and MUFA take place in the subcutaneous fat.

The effects of diets enriched in omega-3 fatty acids on carcass characteristics and the fatty acid profile of intramuscular and subcutaneous fat in pigs

“…This suggests that the composition of fatty acids may vary depending on the type of investigated tissues. Our suggestions are in agreement with the conclusions of other authors (e.g., Raes et al, 2004;Skiba et al, 2011).…”

“…Pigs fed a diet with the moderate and the lowest concentrations of this group of fatty acids had worse Ʃn-6/Ʃn-3 ratio than recommended by the WHO. Moreover, we found that it is better to modify the fatty acid composition of pig tissues by using mixtures of fats than single oils (Raj et al, 2010;Skiba et al, 2011). Similar results have been found by other authors (e.g., Nguyen et al, 2003;Więcek et al, 2010).…”

“…Moreover, meat and fat from pigs fed this diet achieved values most similar to the WHO recommendations. In our previous studies we also found significant differences between the ratio of PUFA/SFA and Ʃn-6/Ʃn-3 in the tissues of pigs of different breeds fed diets supplemented with a single oil (Raj et al, 2010;Skiba et al, 2011). In these studies we found the most preferable ratio of PUFA/SFA in the subcutaneous fat of pigs restrictively fed a diet containing linseed oil, as compared with pigs fed diets supplemented with rapeseed or fish oils.…”

“…Our results are in agreement with other studies (e.g., Bryhni et al, 2002;Flachowsky et al al., 2008;Wood et al, 2008;Guillevic et al, 2009;Skiba et al, 2011).…”

“…, Nguyen et al (2003), Guillevic et al (2009), Raj et al (2010), and Skiba et al (2011). Tissue differences in the concentrations of LA and ALA can be partly explained by the different levels of incorporation of these fatty acids into tissues.…”