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Dietary histidine requirement of Nile tilapia juveniles based on growth performance, expression of muscle-growth-related genes and haematological responses

Author:
Michelato, Mariana, Zaminhan, Micheli, Boscolo, Wilson Rogério, Nogaroto, Viviane, Vicari, Marcelo, Artoni, Roberto Ferreira, Furuya, Valéria Rossetto Barriviera, Furuya, Wilson Massamitu
Source:
Aquaculture 2017 v.467 pp. 63-70
ISSN:
0044-8486
Subject:
Oreochromis niloticus, crude protein, diet, energy, feed conversion, fish, genes, growth performance, histidine, juveniles, muscle development, muscle fibers, myogenin, myostatin, protein efficiency ratio, regression analysis, satiety, water temperature, weight gain
Abstract:
A 100-day feeding trial was carried out to determine the dietary histidine requirement of Nile tilapia juveniles based on growth performance, muscle development, expression of muscle-growth-related genes, biochemical and hematological responses. Nile tilapia juveniles (4.84±0.04g) were fed six extruded practical isonitrogenous (265.7g of crude protein kg−1) and isoenergetic (17.3MJ of gross energy kg−1) diets containing graded levels of histidine (4.2, 5.4, 7.1, 8.9, 9.8 and 11.5gkg−1 dry diet). The feeding trial was conducted in a flow-through system (1.5Lmin−1) at 28°C water temperature, and triplicate groups of fish were hand-fed each diet four times a day until apparent satiation. Final weight, weight gain, feed conversion ratio, protein efficiency ratio and net protein utilization were optimized in fish fed 8.9g of histidine kg−1. Whole-body protein content was enhanced in fish fed 7.1 and 9.8g of histidine kg−1 compared to fish fed 11.5g of histidine kg−1. Active hypertrophic growth process was observed in fish fed 8.9g of histidine kg−1, as confirmed by lower frequency of occurrence of muscle fibers <20µm diameter and higher frequency of occurrence of muscle fibers >50 µm diameter, compared to fish fed 5.4g of histidine kg−1. Fish fed 9.8g of histidine kg−1 showed the highest expression level of MyoD. However, myogenin expression was higher in fish fed 9.8 and 11.5g of histidine kg−1 compared to fish fed 4.2 to 7.1g of histidine kg−1. Myostatin expression was similar among fish from all treatments. Biochemical and haematological responses were not affected in fish fed graded levels of histidine. Based on second-order regression analysis, the dietary histidine requirement for maximum WG of Nile tilapia juveniles was estimated to be 8.2gkg−1, corresponding to 3.1% of crude protein.Histidine is a limiting amino acid in Nile tilapia diets.
Agid:
5308712