Effects of dietary protein and lipid levels on the growth performance, feed utilization, and liver histology of largemouth bass (Micropterus salmoides)

• Published in: Amino acids 2020-07, Vol.52 (6-7), p.1043-1061
• Main Authors: Li, Xinyu, Zheng, Shixuan, Ma, Xuekun, Cheng, Kaimin, Wu, Guoyao
• Format: Article
• Language: English
• Subjects: Amino acids; Analytical Chemistry; Bass; Biochemical Engineering; Biochemistry; Biomedical and Life Sciences; Body weight gain; Calcium; Diet; Dry matter; Fatty liver; Feed efficiency; Fish; Glycogen; Glycogens; Histology; Life Sciences; Lipid metabolism; Lipids; Liver; Micropterus salmoides; Minerals; Morphology; Neurobiology; Original Article; Phosphorus; Physical growth; Proteins; Proteomics; Satiety
• ISSN: 0939-4451; 1438-2199
• DOI: 10.1007/s00726-020-02874-9

The reported requirements of largemouth bass (LMB, which is native to North America) for dietary protein and lipids varied substantially among previous studies, and this fish fed current formulated diets exhibit poor growth performance and pale liver syndrome. Because amino acids and lipids are known to affect hepatic metabolism and function in mammals, it is imperative to understand the impacts of these dietary macronutrients on the growth and liver morphology of LMB. In this study, we designed six isocaloric diets to determine the effects of different dietary crude protein (CP; 40%, 45%, and 50%; dry matter basis) and lipid levels (7.5% and 10%; dry matter basis) on fat and glycogen deposits, as well as hepatosis in LMB. There were four tanks (12 fish per tank, an average initial weight of 18.4 g/fish) per dietary treatment group and the trial lasted for 8 weeks. Fish were fed to apparent satiation three times daily. Results indicated that LMB fed the 45% or 50% CP diet grew faster ( P