Aquaculture Studies 2018, Vol 18, Num, 1     (Pages: 1-10)

Preliminary Effects of Dietary Protein Levels on Muscle Quality and Digestive Enzyme Activities in GIFT-Oreochromis niloticus

Huizan Yang 1-2 ,Jinzhao He 3 ,Min Lv 1 ,Gunghua Huang 1 ,Luting Wen 2 ,Xianda Bi 1 ,Tingjun Hu ,Huawei Ma

1 Guangxi Key Laboratory of Aquatic Genetic Breeding and Healthy Aquaculture, Gaungxi Academy of Fishery Sciences, Nanning City 530021, Guangxi Province, China
2 College of Animal Science and Technology, Guangxi University, Nanning City 530005, Guangxi Province, China
3 Guangxi Aquaculture Introduction and Breeding Center, Nanning City 530031, Guangxi Province, China
DOI : 10.4194/2618-6381-v18_1_01 Viewed : 434 - Downloaded : 251 The effects of 10%, 15%, 20%, 25%, 30%, and 35% dietary protein levels on muscle quality, and digestive enzyme activities in GIFT-O. niloticus were investigated for 12 weeks. A total of 720 juvenile GIFTO. niloticus with initial wet body weight 3.50±0.2 g and length 4.6±0.5 cm were randomly divided into six triplicate groups according to the above protein levels. The results show that muscle quality of GIFT-O. niloticus increased with increasing muscle protein and lipid, amino acid level, fiber area, and muscle water-holding capacity, but decreasing flesh fiber density. The optimal protein level was 25%. Protease activity increased first with the 10%–25% dietary protein level, followed by a decrease as the proportion increased. In conclusion, the 25% dietary protein level was optimal to improve muscle quality and protease activities, which could be regarded as a reference level to produce GIFT-O. niloticus feed. Keywords : GIFT-Oreochromis niloticus, Dietary protein, Muscle quality, Cellularity, Protease