Quantitative description of body composition in grass carp (Ctenopharyngodon idella)

To quantify the body cmposition of grass carp,about 3700 datasets were adopted from 51 studies regarding body composition and morphological parameters of grass carp with body weights ranging from 1.52 to 694.80 g after data searching and collecting from academic database. Through data classification,correlation analysis and linear regression analysis,the overall results in the present experiment suggested that close linear relationships of whole-body protein content and viscera weight (y, g) with body weight of grass carp (x, g) were obtained respectively: y=0.1604x-0.3645, R²=0.994; y=0.1059x-0.3097, R²=0.9875. With an increase of body weight,whole-body lipid and ash contents (especially the lipid content) of grass carp are more susceptible to dietary manipulations. Deposition of 1 g protein resulted in a retention of 4.57 g moisture,while accumulation of 1 g lipid entailed a decrease of 0.95 g moisture in the whole-body of grass carp. In the liver,deposition of 1 g lipid entailed a decrease of 0.66 g moisture,suggesting that the loss rate of moisture driven by lipid deposition is tissue specific in grass carp. The present study also demonstrated that mesentery is an important site for lipid deposition in grass carp,and an increase of lipid accumulation in mesentery,liver and muscle contributes to whole-body lipid deposition. In addition,an increase of whole-body lipid content is accompanied by increased viscera weight. The results in this study are helpful to quantify the body composition of grass carp and provide scientific guidance for its practical production.