Vegetable choline improves growth performance, energetic metabolism, and antioxidant capacity of fingerling Nile tilapia (Oreochromis niloticus)

Abstract

Fish represents an important source of proteins and essential micronutrients for human health, and Nile tilapia (Oreochromis niloticus) is one of the most widespread aquaculture species grown worldwide to meet the growing demand for fish. In this sense, the use of supplemented diets it is important and an interesting approach to improve the growth performance, as the use of vegetable choline (VC). A total of 160 fingerlings Nile tilapia (7.10 ± 0.45 g; 6.13 ± 0.59 cm) were randomly separated into four groups in quadruplicate with 10 fish per aquarium (60 L) as follows: the group T0 (basal diet without VC supplementation), T400 (basal diet supplemented with 400 mg VC/kg of feed), (basal diet supplemented with 800 mg VC/kg of feed), and T1200 (basal diet supplemented with 1200 mg VC/kg of feed), being fed with rate of 6% of total biomass for 60 consecutive days in two equal portions and offered to fish twice a day at 9:00 am and 17:00 h. Thus, the aim of this study was to evaluate whether phosphoryl transfer network, as well as the improvement of antioxidant/oxidant status, can be considered pathways involved in the improvement of growth performance in Nile tilapia (7.10 ± 0.45 g) fed 0.0, 400, 800, and 1200 mg VC/kg of feed for 60 days. VC-supplemented diets were able to increase fish growth and feed intake after 60 days post-feeding compared to the control group. Also, fish from groups supplemented with 800 and 1200 mg VC/kg of feed presented an increase on hepatic pyruvate kinase activity compared to the control group. On the other hand, fish supplemented with 1200 mg VC/kg of feed presented an increase on hepatic glucose levels, while the hepatic lactate levels decreased compared to the control group. Additionally, VC supplementation improves the zootechnical performance. Finally, fish from groups supplemented with 800 and 1200 mg VC/kg of feed presented lower hepatic lactate dehydrogenase and lipid peroxidation levels, while the antioxidant capacity against peroxyl radicals levels were higher compared to the control group. Based on these evidences, VC supplementation can be an interesting alternative to increase growth performance of Nile tilapia fingerlings especially at levels of 800 and 1200 mg VC/kg of feed, which were able to improve the hepatic energy metabolism and antioxidant/oxidant status and subsequently increased the fish growth performance.