Digestive function and serum biochemical parameters of juvenile Cyprinus carpio in response to substitution of dietary soybean meal with sesame seed (Sesamum indicum) cake

A feeding trial was designed to evaluate effects of soybean meal replacement (SBM) with sesame seed cake (SSC) at 0 (SSC0), 25 (SSC25), 50 (SSC50), 75 (SSC75), and 100 (SSC100) % in isoproteic (30%) and isolipidic (8%) diets on the growth performance, digestive function and serum and hematological parameters in Cyprinus carpio. Four hundred and fifty common carp juveniles (83.09 g) were randomly distributed into 15 tanks with a flow-through system. Triplicate groups of fish were hand-fed one of the diets to visual satiation thrice daily for 90 days. The survival rate, growth performance and somatic indices did not show significant differences between treatments. Among feed utilization indicators, nitrogen retention efficiency was significantly higher in SSC25 than in other treatments. Lipid retention efficiency significantly increased from SSC50 to SSC100. The number of white blood cells was significantly higher in SSC0 than other treatments. Significantly higher hemoglobin was observed in SSC75 as compared to SS0 and SSC25. Serum biochemical parameters did not significantly differ between dietary treatments. Dietary SSC resulted in significant increase in calcium ADC and activity of digestive trypsin, chymotrypsin, lipase, α-amylase, and alkaline phosphatase. Significantly higher villi height and intestinal muscle layer width were observed in fish fed the SSC75 diet. The villi width in SSC25 and SSC50 was significantly less than in SSC0. Comparable growth performance, feed utilization, apparent digestibility, digestive function, hematological and serum factors indicated the possibility of 75–100% substitution of SBM by SSC in the diet of juvenile C. carpio.