Supplementary feeding is one of the important and essential part of the brackishwater aquaculture technology for maintaining the growth of the stocked fish and prawn. The quantity of feed to be provided and its utilization by the stock is dependent upon ambient salinity and temperature
Usually, the locally available food substances with a high conversion ratio are preferred. The composition of the feed is determined keeping in view the nutritional requirements of the species stocked.
Several experiments were carried out in formulating a suitable feed of P. monodol1 for application in culture ponds during the last few years. It was found that indegenous materials comprising of deoiled rice-bran (29 g) + soyabean meal (29 g) + marine trash fish (40 g) + vitaminised mineral mixture (2 g) gave better growth when applied @ 5% of the body weight/day. Recently after a number of trials, the following two formulae, using readily available cheap ingredients, have been worked out for feeding the juvenile prawns. In these formulations, complete nutritional requirement of prawns has been considered as the main basis.
FORMULA OF DIET I
Molluscan meal and shrimp meal (1 : 1) 326.8 g each
High gluten wheat starch & corn waste (1 : 1) 1332.2
Molasses + Palm oil + cod liver oil + vitamin mineral 20.0
FORMULA OF DIET II
Algal powder and shrimp meal (1 : 1) 311.75
High gluten wheat starch & corn waste (1: ]) 148.25
Molasses + Palm oil + cod liver oil + vitamin mineral 20.0
mixture
Diet I contains 46.3 % protein and diet II 46.7% protein, Both the feeds are stable in water for more than three hours. The starch content is gelatinised by cooking in hot water in which other ingredients are added. The whole mash could be converted into a dough and pellets be prepared with it. Depending on the consumption and conversion, the feed is given from 2 to ]0% of the body weight of the stocked animals. The required daily ration may be given in instalments either by broadcasting or by serving it in trays kept submerged in the pond.
For biculture and triculture of fish and prawn, a powdered mixture of rice bran (60%), fish or prawn meal (25%) and oil cake (15%) is prepared. The feed mixture is spread over the pond water @ 2 to 5% of the estimated biomass of fish pond. The time of broadcasting should be during early morning or late evening hours. In mixed culture of fishes i. e. M. cephalus, C. chanos and L. parsia, supplemental feeding comprising groundnut oil cake and wheat-bran at 1 : 1 ratio gave favourable growth when applied @ 5% of the body weight/day.
Source-
- Central Inland Fisheries Research Institute, Barrackpore
