Abstract
In the present study, histological changes of hepatopancreas were studied in response of using sodium lactate as a growth promoter to the freshwater prawn Macrobrachium rosenbergii. The prawns were fed on diet with five concentrations of sodium lactate (1, 1.5, 2, 3 and 4g/kg of diet) as food supplement for 103 days. Results showed that R and B-cells were very sensitive to different diets. Slight changes were apparent in the hepatopancreas in the 1% concentration. While, at 1.5 % concentrations, swollen of the cells and enlarged of the vacuoles were observed. Regarding the concentrations of 2%, more accumulation of vacuoles was exhibited. Increase of vacuoles in the R-cells, abnormalities of B-cells, atrophy of the F-cells and pyknosis in the hepatopancreatic cells at 3 & 4% were observed. This investigation and other results of the detailed study of the same authors concluded that the best using concentration of sodium lactate is 1%, because it has mild histological effects and at the same times, it has the best promotion for the growth rate of M. rosenbergii.