Page 110 - 《水产学报》2025年第10期

陈辉，等 水产学报, 2025, 49(10): 109608

Effects of α-lipoic acid supplementation in high-linolenic acid diets on
growth performance and muscle quality of
GIFT Oreochromis niloticus during refeeding

CHEN Hui , LIAO Fan , SHI Quan , LI Yuanyou , XIE Dizhi *
College of Marine Sciences, South China Agricultural University, Guangzhou 510642, China

Abstract: Currently, farmed fish commonly exhibit reduced long-chain polyunsaturated fatty acids (LC-PUFAs) levels in
muscle and deteriorated texture; both modified feeding strategies and functional additives can ameliorate this. To test whether
refeeding with high-linolenic-acid feed supplemented with alpha-lipoic acid has a superimposed effect on the growth and
muscle quality improvement of GIFT Oreochromis niloticus. In this study, three isonitrogenous and isolipidic diets (T1-T3)
were formulated using soybean oil, perilla seed oil and fish oil as fat sources. T1 and T2 groups were fed with soybean oil and
perilla seed oil (T2 group was additionally supplemented with 0.05% alpha-lipoic acid), while T3 group (control group) was fed
with soybean oil and fish oil. GIFT O. niloticus (initial weight about 68 g) that had previously consumed soybean oil feed (T0)
were fed with the above diets in an indoor recirculating water system for 8 weeks. Compared with the control group T3, the
final weight and specific growth rate of fish in T1 and T2 groups were significantly increased, and the feed conversion ratio was
significantly reduced, with no significant difference between the latter two groups. In terms of muscle quality, compared with
the initial fish (T0), the muscle hardness and adhesiveness of fish in T1–T3 groups increased by 43.39%–68.19% and
139.65%–177.89%, respectively. Among the re-feeding groups, the muscle hardness and adhesiveness of fish in T3 and T2
groups were significantly higher than those in T1 group, and the crude fat content was significantly lower than that in T1 group.
Compared with the T0 group, T1–T3 groups showed increases of 29.32%–55.91% and 33.89%–50.45% in whole-body n-3
polyunsaturated fatty acids (n-3 PUFA) and highly unsaturated fatty acids (HUFA, also known as LC-PUFA) respectively, with
corresponding 30.42%–114.82% and 43.78%–66.32% increases observed in muscle tissue. Notably, the T2 group exhibited sig-
nificantly higher levels of eicosapentaenoic acid (EPA) and n-3 PUFA in whole-body samples, as well as docosahexaenoic acid
(DHA) and n-3 PUFA in muscle tissue compared to T1 group, while showing no significant difference from T3 group.Com-
pared with T3 group, the expression levels of key genes involved in LC-PUFA synthesis and metabolism, such as Δ4 fads2,
Δ6Δ5 fads2 (fatty acid desaturase) and elovl5 (long-chain fatty acid elongase), in the liver of fish in T1 and T2 groups were sig-
nificantly upregulated, and the expression level of elovl5 in T2 group was significantly higher than that in T1 group. The addi-
tion of 0.05% alpha-lipoic acid to high-linolenic acid feed and subsequent feeding had a synergistic effect on the growth and
muscle quality of GIFT O. niloticus, and the improvement effect was comparable to that of fish oil feed. The research results
provide technical support for the cultivation of high-quality GIFT O. niloticus.
Key words: GIFT Oreochromis niloticus; high-linolenic acid; alpha-lipoic acid; refeeding; growth performance; muscle quality
Corresponding author: XIE Dizhi. E-mail: xiedizhi@scau.edu.cn

Funding projects: GuangDong Basic and Applied Basic Research Foundation (2024A1515030246)

中国水产学会主办 sponsored by China Society of Fisheries https://www.china-fishery.cn
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