From the results described above, it could be concluded that, higher production of fingerling per unit area is possible by applying modified management technology of proper stocking density, feeding and manuring and repeated use of the waterbodies.
To produce 10 g (10 cm) size fingerling the stocking density should not exceed 14,000 prenursed fry per 1000 m2, and the combination of species should not exceed 5000 grass carp, 7000 silver carp, 3000 mirror/common carp, 5000 catla and 3000 mrigal per 1000 m2. Above this stocking, the individual growth of tested species is hampered. But, if improved food containing cattle blood is applied (Table 8, Feeding type B), the stocking may be increased.
To produce 120–130 kg large size fingerling per 1000 m2 per 35 days cycle about 150 kg feed and for those ponds where grass carp is reared about 100 kg additional duckweed are necessary (Table 8, Type A). If the production target is higher, 200–230 kg/1000 m2, application of cattle blood from 20th days of rearing is essential (Table 8, Type B).
TABLE 8
FEEDING SCHEDULE FOR CARP FINGERLING PRODUCTION
A. Feeding schedule for 120–130 kg production/1000 m2/cycle
Period (day) | Ration kg/1000m2/day | Mustard oil cake (kg) | Wheat bran (kg) | Duckweed (kg) |
0–7 | 0 | 0 | 0 | 0 |
8–14 | 3 | 1.5 | 1.5 | 1 |
15–22 | 5 | 2.5 | 2.5 | 1–2 |
23–34 | 5 | 2.5 | 2.5 | 3–4 |
35–42 | 6 | 3 | 3 | 5–8 |
B. Feeding schedule for 200–230 kg production/1000 m2
Period (day) | Ration kg/1000m2/ day | Mustard oil cake (kg) | Wheat bran (kg) | Cattle blood (kg) | Duckweed (kg) |
0–7 | 0 | 0 | 0 | 0 | 0 |
8–14 | 3 | 1.5 | 1.5 | 0 | 1 |
15–22 | 5 | 2.5 | 2.5 | 0 | 1–2 |
23–34 | 7 | 2.5 | 2.5 | 2 | 3–4 |
35–42 | 10 | 3 | 3 | 4 | 5–8 |
Daily 5–10 kg organic manure/1000 m2 (chicken/cattle manure or fresh rumen contents) is suggested to spread on the water surface of the ponds. Inorganic fertilizers are to be used when necessary. Daily raking of pond bottom is also recommended.
From the present study it may be recommended that --
the improved management system of year-round production of large size fingerlings (average size 10 cm/10 g) should be taken up by the government and transferred to both the public and private sectors trough training and extension services;
government should also try this technique in the Fish Seed Multiplication Farm and there by improve the technology further;
research organizations like the universities and Fisheries Research Institute should conduct further studies to develop a complete technical package on large size fingerling production to met the demand of the country.