To further reduce the cost of feeds in the grow-out culture operation of any kind of fish, proper feeding management should be practiced. It should be remembered that excess feeds pollute the rearing water easily and waste money.
Most feed companies recommend a feeding regime based on the arbitrary weight of the fish at a given day of culture. More Often than not, the recommended feeding is twice the amount of what the fish actually requires. So the amount of feed for that matter should be based on the gross weight of the fish to be fed. This can be computed through the procedure below.
1. Have a good estimate of the fish population. This means that recounting of the stock maybe necessary after the fish have rested after the transport, like 2-4 weeks after stocking. The fingerlings maybe placed temporarily in a net cage in order to perform this procedure easily. Daily mortality should be monitored and recorded also.
2. Conduct regular sampling of the fish for weight every two weeks. This is done by getting about 20 fish in a scoop net and weighing them. The average body weight (ABW) is calculated by dividing the total weight of the fish by the number of fish in the sample.
3. Compute for the gross weight (GW) of the fish. To figure this, multiply the ABW with the standing population at the time of the sampling.
4. Compute the daily ration. Normally, a feeding rate (FR) of 2.5 to 3 percent of the body weight of the fish is given daily if there is no other source of food in the water. For fish cultured in water with high productivity and at low stocking rates, no feeding may be necessary. Otherwise, a supplementary feeding rate of 1 to 1.5 percent of the body weight may be given if natural food is insufficient.
To compute for the DR, multiply the GW with the FR. This represents the ration for the day. If feeding is done twice a day, the FR should should be divided into two. One-half is given in the morning and the other and the other half in the afternoon.
5. Feed gradually. Some fish are active feeders; they eat when they are hungry and go away when they are full. Despite the computed daily ration, the appetite of the fish should be taken into account. It should be remembered that extremes in water temperature and stress lessen the appetite of the fish. Feeding should be stopped once the fish refuse to eat.
Minimizing feed cost is possible and will entail combinations of strategies to achieve profitability and sustainability. With the low market of harvested fish, fish farmers should be resourceful in scouting for cheaper feed ingredients. As for the commercial raisers, toll processing may be a better option since they need bigger volume of feeds. So whether it is a backyard or commercial fish raising, a prudent feed management scheme has to be employed for a more efficient feed use.