Effects of dietary lysine level on the content and fatty acid composition of intramuscular fat in late-stage finishing pigs

Abstract

22This study was conducted to investigate how dietary lysine level affects the intramuscular 23 fat (IMF) content and fatty acid (FA) composition in late-stage finishing pigs. Nine crossbred 24 barrows (94.4 ± 6.7 kg BW) were randomly allotted to three treatment groups (n = 3). Three corn 25 and soybean-meal based diets were formulated to meet the NRC (2012) requirements for various 26 nutrients except for lysine, whose concentrations were 0.43%, 0.71%, and 0.98% (as-fed basis) 27for Diets 1 (lysine-deficient), 2 (lysine-adequate), and 3 (lysine-excess), respectively. After 5 28 weeks of ad libitum access to diets, pigs were harvested and longissimus dorsi samples were 29 collected. The IMF content and FA composition of the samples were analyzed by gas 30 chromatography. Results showed that the IMF content of the muscle was increased linearly (P < 31 0.05) with decreasing dietary lysine level from 0.98% to 0.43%. Dietary lysine level altered the 32 composition of FA, especially the unsaturated FA, in the muscle. Particularly, the percentages of 33 C18:1 n-9 and total mono-unsaturated FA were higher, while the percentages of C18:2 n-6 and 34 total poly-unsaturated FA were lower, in the muscle of the pigs fed Diet 1. Collectively, dietary 35 lysine deficiency increased the proportion of mono-unsaturated FA and decreased the proportion 36 of poly-unsaturated FA, which may benefit pork palatability. 37

Enrichment of Broiler Chickens’ Meat with Dietary Linseed Oil and Lysine Mixtures: Influence on Nutritional Value, Carcass Characteristics and Oxidative Stress Biomarkers

“…Nevertheless, the highest omega-6 values of linoleic acid and arachidonic acid associated with dietary mixtures containing high lysine levels may also reveal a boosting effect attributable to high lysine levels. Similar patterns were reported in pigs fed low and high dietary lysine than the optimum one, where LA, LNA and total PUFA percentages rose significantly ( p ≤ 0.014) with increased dietary lysine levels [ 48 ]. Increased linseed oil intake, similarly, resulted in higher de novo ω-3 PUFA synthesis and, as a result, increased total PUFA levels in chicken meat [ 45 , 60 ].…”

“…In the current study, stearic acid is the only fully saturated fatty acid increased by increasing dietary levels of linseed and/or lysine. An inverse relationship was found between the percentages of stearic acid, total SFA and the amount of dietary lysine in pigs [ 48 ]. The addition of linseed oil was associated with a decrease in SFA in chicken meat [ 47 ].…”

“…Similar findings have been noted previously after 35 days of linseed supplementation in chicken breast meat [ 47 ]. In pork, the concentrations of PtA and OA increased linearly with decreasing dietary lysine level [ 48 ]. Current study findings revealed that the broiler group fed elevated dietary levels of linseed and lysine exhibited the highest values of total ω-3 fatty acids (ALN, EPA and DHA).…”

Expression of Myosin Heavy Chain and Some Energy Metabolism-Related Genes in the Longissimus Dorsi Muscle of Krškopolje Pigs: Effect of the Production System

“…Although, lower dietary lysine levels have been previously correlated with a higher proportion of monounsaturated fatty acids, the LD IMF content did not differ substantially between the groups ( 17 ). This argues against the predominant effect of lysine, as it has been reported that the IMF content of the muscle increases with decreasing dietary lysine levels ( 43 ).…”

Influence of dietary protein content on the chemico-physical profile of dry-cured hams produced by pigs of two breeds

“…The use of low protein and low amino acid feeds (LP) has recently emerged as one of the best strategies to reduce the environmental release of N compounds from pig farms. In many experiments, LP diets have been found to increase fat cover thickness and intramuscular fat 12–14 . Greater fat cover thickness reduces the water losses during ripening, and this would exert positive effects on the final quality of the product 15,16 .…”