Optimizing Dietary Protein and Lipid Levels for Greenfin Filefish (Thamnaconus septentrionalis) in Practical Feeds: Effects on Growth Performance, Feed Utilization, and Physiological Status.
4 affiliations
- 1Shandong Marine Resource and Environment Research Institute Yantai 264006 China.
- 2Shandong Shengsuo Feed Technology Co., Ltd. Yantai 265500 China.
- 3Daoyi Human Resources Service Co., Ltd. Yantai 264003 China.
- 4Shanghai Ocean University Shanghai 201306 China shou.edu.cn.
Abstract
The study investigated the optimal dietary protein and lipid levels for greenfin filefish (Thamnaconus septentrionalis) using two sequential, growth trial-based experiments with practical formulations. Experiment I was designed to establish the quantitative protein requirement. Six isolipidic and isoenergetic diets with graded crude protein levels (38%, 41%, 44%, 47%, 50%, and 53% of dry matter) and a fixed lipid content of 10% were fed to triplicate groups of fish (5.56 g) for 56 days. Growth performance, feed utilization, and physiological responses were evaluated. Weight gain, specific growth rate, and feed conversion ratio all showed significant quadratic responses to dietary protein level, peaking at 47% protein. Quadratic regression analysis based on growth pinpointed the optimal dietary protein requirement at 45.93%-45.99%. This optimal level not only yielded the highest final biomass and best feed efficiency but was also associated with the highest hepatic total antioxidant capacity (T-AOC), indicating an enhanced systemic antioxidant defense without provoking oxidative damage, as malondialdehyde (MDA) levels remained stable across all protein groups. Subsequently, Experiment II was conducted to determine the lipid requirement at the established optimal protein level (46%) by testing six isonitrogenous diets with graded lipid levels (6%, 7.5%, 9%, 10.5%, 12%, and 13.5%). Quadratic regression based on growth revealed an optimal dietary lipid range of 9.69%-10.39%. While lipid levels up to 10.5% promoted growth and improved feed conversion through a protein-sparing effect, inclusion levels exceeding 12% induced metabolic dysfunction. This was evidenced by a sharp decline in T-AOC and superoxide dismutase activity, a significant increase in MDA, elevated hepatosomatic index (HSI), and reduced lipid retention efficiency. Notably, the concurrent accumulation of hepatic unsaturated fatty acids and rise in MDA at high lipid intakes suggested these endogenous pools became substrates for peroxidation, overwhelming the antioxidant system. Therefore, a practical formulation containing 46% protein, 9.7%-10.4% lipid, and 33% carbohydrate, with a crude protein-to-gross energy ratio (CP/GE) of ~23.93-24.59 mg/kJ, is recommended for juvenile greenfin filefish (<20 g).
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BibTeX
@article{song2026optimizing,
title = {{Optimizing Dietary Protein and Lipid Levels for Greenfin Filefish (Thamnaconus septentrionalis) in Practical Feeds: Effects on Growth Performance, Feed Utilization, and Physiological Status.}},
author = {Zhidong Song and Huadong Li and Peiyu Li and Lei Yu and Xihan Xu and Jian Zhang and Yuming Sun and Chengqiang Wang and Yige Wu and Xiaoyan Wang and Yongzhi Sun},
journal = {Aquaculture nutrition},
year = {2026},
month = oct,
doi = {10.1155/anu/2928232},
url = {https://europepmc.org/article/MED/42923878},
note = {CC BY},
}
RIS
TY - JOUR
TI - Optimizing Dietary Protein and Lipid Levels for Greenfin Filefish (Thamnaconus septentrionalis) in Practical Feeds: Effects on Growth Performance, Feed Utilization, and Physiological Status.
AU - Zhidong Song
AU - Huadong Li
AU - Peiyu Li
AU - Lei Yu
AU - Xihan Xu
AU - Jian Zhang
AU - Yuming Sun
AU - Chengqiang Wang
AU - Yige Wu
AU - Xiaoyan Wang
AU - Yongzhi Sun
PY - 2026
DA - 2026/10/22
JO - Aquaculture nutrition
DO - 10.1155/anu/2928232
UR - https://europepmc.org/article/MED/42923878
AB - The study investigated the optimal dietary protein and lipid levels for greenfin filefish (Thamnaconus septentrionalis) using two sequential, growth trial-based experiments with practical formulations. Experiment I was designed to establish the quantitative protein requirement. Six isolipidic and isoenergetic diets with graded crude protein levels (38%, 41%, 44%, 47%, 50%, and 53% of dry matter) and a fixed lipid content of 10% were fed to triplicate groups of fish (5.56 g) for 56 days. Growth performance, feed utilization, and physiological responses were evaluated. Weight gain, specific growth rate, and feed conversion ratio all showed significant quadratic responses to dietary protein level, peaking at 47% protein. Quadratic regression analysis based on growth pinpointed the optimal dietary protein requirement at 45.93%-45.99%. This optimal level not only yielded the highest final biomass and best feed efficiency but was also associated with the highest hepatic total antioxidant capacity (T-AOC), indicating an enhanced systemic antioxidant defense without provoking oxidative damage, as malondialdehyde (MDA) levels remained stable across all protein groups. Subsequently, Experiment II was conducted to determine the lipid requirement at the established optimal protein level (46%) by testing six isonitrogenous diets with graded lipid levels (6%, 7.5%, 9%, 10.5%, 12%, and 13.5%). Quadratic regression based on growth revealed an optimal dietary lipid range of 9.69%-10.39%. While lipid levels up to 10.5% promoted growth and improved feed conversion through a protein-sparing effect, inclusion levels exceeding 12% induced metabolic dysfunction. This was evidenced by a sharp decline in T-AOC and superoxide dismutase activity, a significant increase in MDA, elevated hepatosomatic index (HSI), and reduced lipid retention efficiency. Notably, the concurrent accumulation of hepatic unsaturated fatty acids and rise in MDA at high lipid intakes suggested these endogenous pools became substrates for peroxidation, overwhelming the antioxidant system. Therefore, a practical formulation containing 46% protein, 9.7%-10.4% lipid, and 33% carbohydrate, with a crude protein-to-gross energy ratio (CP/GE) of ~23.93-24.59 mg/kJ, is recommended for juvenile greenfin filefish (<20 g).
SN - 1353-5773
SN - 1365-2095
ER -