Reducing Dietary Protein Content by Increasing Carbohydrates Is More Beneficial to the Growth, Antioxidative Capacity, Ion Transport, and Ammonia Excretion of Nile Tilapia (Oreochromis niloticus) under Long-Term Alkalinity Stress

Figure 3

Expression of genes related to glutamine synthetase (a) and glutaminase 2 (b) in the liver and plasma ammonia (c) of O. niloticus fed different dietary protein to carbohydrate ratios in freshwater or alkaline water for 50 days. Data are expressed as the mean ± SEM (standard error of the mean) (n = 3). Different letters in the same histogram show significant differences (). Indicates a significant difference between different alkalinity levels within the same diet protein–carbohydrate ratios (). Indicates a significant difference between different alkalinity levels within the same diet protein–carbohydrate ratios (). gs, glutamine synthetase and gls 2, glutaminase 2.

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