The Requirement and Protective Effects of Dietary Protein against Chronic Ammonia Exposure in Juvenile Genetically Improved Farmed Tilapia (Oreochromis niloticus)

作者：Xing Lü, Zhehui Ji, Meizi Wang, Juan Tian, Li-Xue Dong, Zhongbao Guo, Yongju Luo, Hua Wen, Ming Jiang · 发表于：Aquaculture Nutrition · 年份：2023 · DOI：10.1155/2023/6306517 · 被引用次数：12 · 研究领域：Aquaculture Nutrition and Growth、Aquaculture disease management and microbiota、Reproductive biology and impacts on aquatic species

Ammonia is a key risk factor in intensive aquaculture systems. This experiment is aimed at investigating the influence of dietary protein levels on genetically improved farmed tilapia (GIFT, Oreochromis niloticus) under chronic ammonia stress. GIFT juveniles of 4.00 ± 0.55 g were exposed to high ammonia level at 0.88 mg/L and fed with six diets comprising graded protein levels at 22.64%, 27.26%, 31.04%, 35.63%, 38.47%, and 42.66% for 8 weeks. The fish in negative control was fed the diet with 31.04% protein in normal water (0.02 mg ammonia/L water). Our results showed that high ammonia exposure (0.88 mg/L) caused significant decrease in fish growth performance, hematological parameters, liver antioxidant enzymes (catalase and glutathione peroxidase), and gill Na+- and K+-dependent adenosine triphosphatase (Na+/K+-ATP) activity. When fish were under high ammonia exposure, the weight gain rate, special growth rate, feed efficiency, and survival rate elevated significantly with dietary protein supplementation increase to 35.63%, whereas protein efficiency ratio, hepatosomatic index, and viscerosomatic index showed a decreased tendency. Dietary protein administration significantly enhanced crude protein but reduced crude lipid contents in the whole fish. Fish fed diets with 35.63%-42.66% protein had higher red blood cell counts and hematocrit percentage than fish fed 22.64% protein diet. The values of serum biochemical indices (lactate dehydrogenase, aspartate aminotran...