The effects of calcium supplemented diets on growth performance of crayfish (Astacus leptodactylus Eschscholtz, 1823)

This study was conducted to investigate the effects of dietary calcium carbonate supplementation in diet on survival rate, growth performance and feed utilization of crayfish fry (Astacus leptodactylus). Average initial weight was 0.04±0.001 g and length was 11.02±0.099 mm of newly hatched 600 crayfish were stocked randomly in twelve aquariums (50 crayfish/aquarium). The calcium carbonate added to the feed was 1%, 3% and 5%. The control group was fed diets without calcium carbonate supplementation. Four experimental diets were supplemented with calcium carbonate at a rate of 0%, 1%, 3% and 5%. After 90 days of the feeding trial, crayfish fed 1%, 3% and 5% calcium carbonate diets had slightly higher weight gain and specific growth rate than control group (p>0.05). However, all calcium carbonate diets was significantly increased survival rate when compared to control group (p<0.05).These results indicate that dietary supplementation of 5% CaCO3 in the crayfish diets could increase survival rate and growth performance. In conclusion, the 5% of calcium carbonate can be useful in crayfish diets.Keywords: Crayfish, calcium carbonate, growth performance, survival rate