Aquaculture has long been practiced in Thailand. The species commonly cultured are catfish (Clarias spp.), stripped catfish (Pangasius striatus), snakehead fish (Ophiocephalus striatus) and tilapia (Sarothero-don niloticus). Among these species, catfish (Clarias batrachus), has been particularly popular because it is easy to culture, fast growing, and the crop turn-over time is relatively short when compares to other species. Moreover, there is a strong demand for catfish because it is tasty and the price is relatively low comparing to other sources of animal protein. The objective of this thesis was to study cost and return of commercial catfish production starting from seed fish operations to grow-out fish culture in the earth ponds. The study was carried out in Tambon Pang Klua, Amphoe Bang Pa Kong of Changwat Chacherng sao in 1981. In addition, cost and return of catfish culture in concrete tanks of Department of Aquaculture, Faculty of Fisheries, Kasetsart University during the same period were also investigated. This new method of cultivation has reduced risk caused by disease. Primary data were obtained from the farmer of the farm investigated and secondary data were reviewed from literatures in order to analyze capital investment at the beginning of the operation, present investment and cost and return of seed stock operations. Cost and return of grow-out catfish culture in earth ponds and concrete tanks were compared. Finally, problems confronting fish farmers were also studied. The result of the study indicated that seed stock operations in the area of 90 rai started with the capital investment of baht 753,808 or at the present investment of baht 1,156,810 while the capital investment of 10 concrete tanks cost 164,400 or baht 165,400 if constructed at present.
A successful seed stock operation requires proper circumstances and climate. Farmers usually stop operating for a few months during winter time because of high mortality rate and slow growth. It takes 20 days to produce on crop of larvae with the average of 10 to 12 crops per year. On the average, the farm investigated produces 5,083,335 units of larvae per crop, selling at baht 0.50 per 100 units. The cost of production was baht 0.32 per 100 units. Larvae can be stocked in the nursing pond up to three stages namely fry and fingerlings of 3 and 5 centimeters in length with the nursing period of 14, 42 and 30 days and the survival rate of 31, 30 and 25 percent respectively. The cost of production of the three stages were baht 3.01, 3.80 and 4.97 per 100 units with the selling price of baht 5.20, 10.40 and 15.60 respectively. The grow-out fish farmers prefer 5 cm fingerlings to the smaller stages. Using own seed stock reduces cost of production. The cost of production of catfish in the earth ponds for the period of 5 months was bath 16.54 per kilogram, selling at baht. 26.33 per kilogram. Culturing catfish in the concrete tanks for 3 months cost baht 17.68 per kilogram, selling at baht 24.00 per kilogram. Selling price of the latter was lower because they were smaller in size and also due to the condition of the supply-demand of the product in a certain period. It can be observed that cost of production per kilogram of catfish cultured in the concrete tanks was baht 1.14 higher than in the earth ponds partly because of the cost of manufactured feed used and partly because of not having own seed stock. Net profit was also lower in concrete tank rearing. Even though concrete tank rearing required shorter cultural period which enabled cultivation of 3-4 crops per year, the comparison of the rates of return per annual on capital employed in earth pond rearing and concrete tank rearing revealed that the rate of return on investment in concrete tank rearing is 47.43 percent while that of the earth pond rearing is 427.46 percent.
The difference in the rates of return is due to the high cost of the concrete tank construction and the higher cost of concrete tank rearing as mentioned above. However it is easier to control disease in the concrete tanks. Major problems in seed stock operations and catfish culture were insufficient water during summer, disease, uncertainty in market prices and the escalating input prices. Recommendations for seed stock operations and grow-fish culture were as follow : 1. Hatchery field should be located close to the canal with storage pond to store water. 2.Nursing pond should be of draining type. 3. In expansion of the business one should consider producing own seed stock and culture in the concrete tank which will give a better opportunity of obtaining higher income due to lower risk from disease. 4. Government should help support fish farmers by providing technical knowledge such as cultural technique, feed mix and disease control. 5. Government should provide short term loan to fish farmers. 6.Fish farmers should organize producer’s association in order to enhance their bargaining power and help each other.
