Extension Study On Tilapia Culture In Factory Remaining Hot Water System

Tilapia, originated from Africa, is becoming a major cultured fish all around world due to its advantages of fast growth, wide food sources, high reproduction ability, less disease, good flesh quality and high production capacity. FAO of UN is devoting in extension tilapia to the worldwide aquaculture at present. But its less tolerance to the lower temperature constrains the development in China. This paper focused on overwintering and grow-out of tilapia by utilizing abundant resources of remaining heat in Xuzhou city in order to make good economic benefit.In this paper, three overwintering systems, i.e. factory remaining hot water, remaining vapor and boiler heating system, were adopted in tilapia overwintering. Every step, such as site selection, pond and fish preparation, cultivation of fish, fish selection, timing of overwintering, stocking density and managements during overwintering, was compared among three systems. The results of data analysis showed that the survival rate in remaining hot water system was 12% higher than in remaining vapor system and 21.25% higher than in boiler heating system. The overwintering cost in remaining hot water system was 735 Yuan/m~3, which was 18 Yuan lower than in remaining vapor system and 71.4 Yuan lower than in boiler heating system. The profit in remaining hot water system was 201 Yuan/m~3, which was 162 Yuan higher than in remaining vapor system and 275.4 Yuan higher than in boiler heating system. This result demonstrated the remaining heat systems had more advantage than boiler heating system. The grow-out comparison experiments were also taken for the tilapia among remaining hot water system, remaining vapor system and normal culture system. The comparison of area, benefit and net profit among three systems were carried out by using Linked Substitution in the Factor Analysis Method of economics analysis. The result was that the net profit in remaining hot water system was 10845 Yuan higher than remaining vapor system, and 85365 Yuan higher than normal culture system. The advantages and constraint remaining heat systems were discussed. The all-male tilapia production was also carried out by hybridization between Oreochromis aureus and O. niloticus. The new way of all-male tilapia production improved tilapia seed quality in Xuzhou City. The prospects on tilapia stock improvement, industrialization, informatization and international market exploitation were made at last.