Combined effects of dietary arginine, leucine and protein levels on fatty acid composition and gene expression in the muscle and subcutaneous adipose tissue of crossbred pigs

Abstract

The cumulative effects of dietary arginine, leucine and protein levels on fat content, fatty acid composition and mRNA levels of genes controlling lipid metabolism in pig longissimus lumborum muscle and subcutaneous adipose tissue (SAT) were investigated. The experiment was performed on fifty-four intact male pigs (Duroc £ Pietrain £ Large White £ Landrace crossbred), with a live weight ranging from 59 to 92 kg. The pigs were randomly assigned to one of six experimental treatments (n 9). The treatments followed a 2 £ 3 factorial arrangement, with two levels of arginine supplementation (0 v. 1 %) and three levels of a basal diet (normal protein diet, NPD; reduced protein diet, RPD; reduced protein diet to achieve 2 % of leucine, RPDL). The results showed that dietary arginine supplementation did not affect the intramuscular fat (IMF) content and back fat thickness, but increased the total fat in SAT. This effect was associated with an increase in fatty acid synthase (FASN) and stearoyl-CoA desaturase (SCD) mRNA levels in SAT, which suggests that arginine might be involved in the differential regulation of some key lipogenic genes in pig muscle and SAT. The increase in IMF content under the RPD, with or without leucine supplementation, was accompanied by increased FASN and SCD mRNA levels. Arginine supplementation did not influence the percentage of main fatty acids, while the RPD had a significant effect on fatty acid composition in both tissues. Leucine supplementation of RPD did not change IMF, total fat of SAT and back fat thickness, but increased 16 : 0 and 18 : 1cis-9 and decreased 18 : 2n-6 in muscle.

Three differently generated salmon protein hydrolysates reveal opposite effects on hepatic lipid metabolism in mice fed a high-fat diet

“…Dietary proteins may play a role in mechanisms affecting fatty acid composition (Bjørndal et al, 2013;Leveille, Tillotson, & Sauberlich, 1963). The amino acid composition of the diet has been shown to influence lipogenesis and desaturation, as tyrosine down-regulates hepatic D6 activity (Peluffo, Nervi, Gonzalez, & Brenner, 1984), and arginine and leucine can regulate the gene expression of Scd1 and Fas in muscle and adipose tissue (Madeira et al, 2014). Here, the amino acid composition did not differ to a large extent since they were all dominated by amino acids from casein.…”

Effect of dietary kapok oil supplementation on growth performance, carcass traits, meat quality and sensory traits of pork in finishing‐pigs

“…‘Sustained juiciness until swallow’ was positively correlated with SFA and C18:0 and negatively correlated with C14:1 in LM. Madeira et al () reported that juiciness was positively correlated with C16:1 and negatively correlated with C18:2. Correlations between fatty acid composition, tenderness and palatability of pork should be investigated further to shed light on the multitude of other factors that may affect sensory traits.…”

Betaine and arginine supplementation of low protein diets improves plasma lipids but does not affect hepatic fatty acid composition and related gene expression profiling in pigs

“…Quantification of FAME in liver was performed using a gas chromatograph Agilent Technologies 7890A (Agilent Technologies, Santa Clara, CA, USA), equipped with a flame ionisation detector (GC‐FID) and a Supelcowax™ 10 capillary column (30 m × 0.20 mm i.d., 0.20 μm film thickness; Supelco, Bellefonte, PA, USA). Gas chromatographic conditions and fatty acid identification are described in detail in Madeira et al . The quantification of total FAME was done using nonadecanoic acid (19:0) as the internal standard.…”

“…Recent studies have shown that some feeding strategies, such as reduced protein diets and amino acids supplemented diets improve fat partitioning in pigs . Betaine is a naturally occurring tertiary amine (trimethyl glycine) in most living organisms formed by the oxidation of choline .…”

“…4 Recent studies have shown that some feeding strategies, such as reduced protein diets and amino acids supplemented diets improve fat partitioning in pigs. [5][6][7] Betaine is a naturally occurring tertiary amine (trimethyl glycine) in most living organisms formed by the oxidation of choline. 8 Its physiological functions are as an organic osmoprotectant or as a methyl donor, which may partially reduce the requirements for other methyl donors in lipid metabolism.…”