Open AccessEffects of dietary n‐6 polyunsaturated fatty acids on growth performance, body composition, haematological parameters and hepatic physiology of juvenile tiger puffer ( Takifugu rubripes )
Author(s) -
Xu Houguo,
Liao Zhangbin,
Zhang Qinggong,
Wei Yuliang,
Liang Mengqing
Publication year - 2019
Publication title -
aquaculture nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.941
H-Index - 79
eISSN - 1365-2095
pISSN - 1353-5773
DOI - 10.1111/anu.12924
Subject(s) - biology , polyunsaturated fatty acid , glycogen , takifugu rubripes , juvenile , food science , feed conversion ratio , fatty acid , biochemistry , medicine , endocrinology , body weight , gene , ecology
A 74‐day feeding trial was conducted to investigate the efficacy of n‐6 polyunsaturated fatty acid (n‐6 PUFA) in diets for tiger puffer. Six experimental diets with graded levels of n‐6 PUFA (from 6.01 to 37.98 g/kg) replacing saturated fatty acids (SFAs) were used in this study. Increasing levels of n‐6 PUFA resulted in decreased weight gain (from 472.6% to 349.4%), feed efficiency and crude protein content in fish, but increased lipid accumulation in whole fish and liver. Liver samples from fish fed the lowest and highest level of n‐6 PUFA were subjected to transcriptomic assay. Analysis of the differentially expressed genes showed that high dietary levels of n‐6 PUFA tended to induce glycolysis and triacylglycerol biosynthesis, but reduce synthesis of amino acid and protein, and cause impairment to liver health. The mitochondrial DNA copy number, activity of mitochondrial respiratory chain complex I and glycogen content in the liver, which indicate energy supply status, significantly decreased with increasing levels of dietary n‐6 PUFA. In conclusion, high n‐6 PUFA/SFA ratios in diet led to reduced energy supply (by approximately 50%) and increased hepatic lipid accumulation (by 55%), which probably consequently negatively affect protein synthesis, liver health and growth of tiger puffer.