Abstract:

Total ninety-three samples of Oreochromis niloticus were selected randomly from cultured population in July and August 2009, and related biochemical components in muscle, liver, gonad and mesenteric fat of each sample were mensurated. Some components which have significant correlation with energy density were selected as predicting factors, and then predicting equations for energy density of different tissues were established. The results showed that there were significant linear relationships between energy density and crude fat content in muscle and liver(P<0.01), by analysis of covariance on the regression equations, two common predicting equations for energy density in muscle and liver were established as following: Em = 0.196 Fm +21.931 (r = 0.902) and El = 0.187 Fl +19.697 (r = 0.914). The significant linear relationship could also be found between energy density and dry mass content in mesenteric fat(P<0.01), and the correlation could be described as Ef = 0.159 Df + 23.973（r=0.917）. Through statistical analysis, crude fat content and dry mass content were selected as predicting factors respectively for ovary and spermary, and the respective predicting equation were established as following: Eo = 0.118 Fo + 25.493（r=0.909）and Es = 0.268 Ds + 19.697（r=0.905）.