Open AccessUsing stable isotope analysis to assess the relationship among dietary protein sources, growth, nutrient turnover and incorporation in Nile tilapia ( Oreochromis niloticus )
Author(s) -
Zhou Hui,
Gu Binhe
Publication year - 2020
Publication title -
aquaculture nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.941
H-Index - 79
eISSN - 1365-2095
pISSN - 1353-5773
DOI - 10.1111/anu.13091
Subject(s) - nile tilapia , oreochromis , biology , protein turnover , δ13c , zoology , stable isotope ratio , fish meal , soybean meal , nutrient , meal , δ15n , tilapia , biochemistry , food science , fish <actinopterygii> , fishery , ecology , protein biosynthesis , raw material , physics , quantum mechanics
Nile tilapia (1.20 g) were fed for 56 days in five treatments (FM100 containing only fish meal [FM] as a protein source; soybean meal (SBM) replace 25%, 50%, 75% and 100% of FM protein in the diets of FM75, FM50, FM25 and FM0, respectively) to assess the effects of dietary protein sources on growth, turnover half‐life of nitrogen and carbon stable isotopes (δ 13 C and δ 15 N) in muscle, isotope discrimination factors (Δ 15 N and Δ 13 C), and the relative contribution of protein sources to muscle growth. Results showed that the final body weight, weight gain and specific growth rate of fish fed diet FM25 were significantly higher than other treatments ( p < .05). By day 35, fish under all treatments reached isotopic equilibrium, and the equilibrium values consistently increase as a function of stable isotope values in diets. Growth accounted for most isotopic changes in muscle and resulted in significantly shorter half‐lives of nitrogen and carbon in FM25 ( p < .05). The Δ 15 N of FM25 and Δ 13 C of FM0 were significantly lower than other treatments ( p < .05). The proportional contributions of SBM protein were significantly higher than their respective levels in FM75 and FM25 ( p < .05), indicating a preferential incorporation of nitrogen from the SBM in muscle tissue.