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Supplementing pig diets with lecithin has been shown to increase the digestibility of fat and meat quality due to a decrease in pork chewiness and hardness. Moreover, soybean lecithin is also rich in unsaturated fatty acids, which may regulate fatty acid metabolism and influence the fat quality of pork. However, there are scarce studies about the effects of dietary lecithin on fatty acid metabolism and lipid metabolism of pigs. Therefore, the aim of the present study was to evaluate the effects of a low dose of dietary lecithin and L-carnitine on the fatty acid composition and lipid-metabolic gene expression in subcutaneous fat and longissimus thoracis of growing-finishing pigs. For that purpose, a total of 160 crossbred barrows (Landrace × Yorkshire, initial BW 45 ± 1.7 kg) were used in an 80d study with 5 pigs/pen and 8 pens/treatment. A randomized block design with a 2x2 factorial arrangement of treatments was used: 1) dietary lecithin supplementation (0 vs. 4 g/kg, as-fed basis) and 2) dietary L-carnitine supplementation (0 vs 50 mg/kg, as-fed basis).
As a result, the total PUFA, C18:2n-6 and C18:3n-3 in subcutaneous fat were increased by lecithin, however, the inclusion of lecithin together with L-carnitine decreased total PUFA, C18:2n-6 and C18:3n-3. L-Carnitine increased the IMF content when supplemented with lecithin but no effect was observed without lecithin supplementation. L-Carnitine increased the mRNA expression of CPT1A, HSL, FABP4 and CRAT; and reduced the mRNA expression of FAS and ACCa in subcutaneous fat. Lecithin increased the mRNA expression of ACCa and ME1 in longissimus thoracis. L-Carnitine increased the mRNA expression of FAS in longissimus thoracis when supplemented with lecithin but no effect was observed without lecithin supplementation.
In conclusion, supplementing lecithin increased the PUFA in the subcutaneous fat and longissimus thoracis. However, the effect was opposite when combined with L-carnitine, although the IMF content was increased. Dietary L-carnitine increased the lipolytic gene expression and reduced the lipogenic gene expression in subcutaneous fat. In longissimus thoracis, dietary lecithin increased the lipogenic gene expression. Given these results, further research, such as consumer panels should be done to confirm the effects of lecithin on pork quality.
Meng, Q., Sun, S., Sun, Y., Li, J., Wu, D., Shan, A., Shi, B., & Cheng, B. (2018). Effects of dietary lecithin and L-carnitine on fatty acid composition and lipid-metabolic genes expression in subcutaneous fat and longissimus thoracis of growing-finishing pigs. Meat science, 136, 68-78. https://doi.org/10.1016/j.meatsci.2017.10.012