T.A. SETHURAMALINGAM, K. ALANKARA AHILA, N.S. ALAGAR AND P. SHUNMUGA VADIVAMMAL
Abstract
Three types of probionts namely enriched Lactobacillus sporogenes (38 x 10'; 76 x 10'; 182X 10' and 285 x 104), Saccharomyces cerevisiae (LL: 93 x 10°, LH: 31 x 109 HL: 62 x I07 and HH: 31 x 106) and Spirulina maxima (25, 50, 75 and 100% from 16 mg/stock) were incorporated into fat rich formulated diets and fed to Cyprinus carpio fingerlings (420 ± 0.67mg) for 41 days. A control diet was also prepared using fish meal, without probiont incorporation. Among the three probionts tested. a significant increase in the specific growth rate (SGR) was observed in yeast and Spirulina incorporated diets than bacterial series diet fed fishes. This was evidenced by the low (best) food conversion ratio produced by the fish when fed with yeast (LL, LH, HL) as well as spirulina (25 and 50%) incorporated diels. The protein intake (PI) and protein efficiency ratio (PER) were also higher in the respective concentrations of probionts incorporated diets. The influence of probionts on the fat mobilization and energy allocation were evidenced from the adhision of yeast cclls in the gut of C. carpi° fingcrlings. Spirulina series fed fish showed a high protein intake and protein efficiency ratio because of the capacity of the probiont to mobilize the resources from the feed and increased the bioavailability of the nutrients. The improvement in the gut flora, and microbial balance could have enhanced the lipid digestibility and influenced the fat metabolism to generate sufficient amount of energy. A significant increase of body fat and moderate increase of body protein in fish fed with yeast and spirulina series diets were observed from this experiment. There was no significant change in the body carbohydrates even in LAB series fed fish. In tbe present study individual effect of probiont was noticeable in fish which influenced the bioavailability of specific nutrients from the diets. Fatty fishes were produced from spirulina and yeast series of feed which exhibited high protein efficiency ratio. So it could be presumed that using probionts at specific concentrations, it was easy to formulate cost effective feed for carps. It was also evidenced that apart from sparing effect of lipid for protein, the fats (oil) could be used along with yeast in fish feed more effectively to promote protein utilization by enhancing the bioavailability of specific nutrients.