Good catfish feed contains 32 to 36 percent protein, 6 percent fat, 10 to 20 percent carbohydrates, and 10 to 15 percent fiber. A minimum of 8 percent of the ration should be from fishmeal and all feeds should contain the recommended vitamins. Ingredients used in making feeds vary widely, depending on availability and cost.
Feeds are sold as floating or sinking pellets and as finely ground meal or crumbles. Floating pellets cost more but are more stable than sinking pellets. They also enable you to determine whether the fish are feeding. If they are not feeding, find the cause and correct it.
Some experienced fish farmers prefer sinking pellets because of the lower cost and they have learned to tell whether the fish are feeding normally by observing the activity of the fish in the feeding areas.
There is little or no difference in fish growth between the use of floating feeds and sinking feeds. Some farmers mix a small amount of floating pellets with sinking pellets so they can observe feeding activity more easily.
Fry should be fed as soon as they leave the nest or swim up in the holding vats or tanks. Meal or crumbles made from a good-quality catfish feed is used primarily for fry. Fry may take the feed more readily if a jar of baby food liver is added to each pound of meal or crumbles. In screened holding boxes, feed only as much as the fry will eat in 20 or 30 minutes. In ponds, feed 2 to 3 pounds per surface acre each day. Gradually increase the quantity of feed to the amount they will eat in 20 to 30 minutes. As the fry approach fingerling size and are feeding well, seine and weigh a sample of fish every 2 or 3weeks and adjust the feed to about 3 percent of the total weight of fish in the pond.
Use ;a-inch pellets for fingerlings from 2 to 6 inches long, ~6-inchpellets for fish up to one-half pound, and JB-inch pellets for larger fish. Pelleted catfish feeds should have good stability and remain intact for at least 10 minutes in water.
The feed allowances are based on rations containing 36 percent protein and approximately 2.9 kcal of digestible energy per gram of protein. If feeds of different protein and energy concentrations are used, daily allowances should be adjusted proportionally.31t is risky to exceed 30 Ibiacreiday unless water is flowing through the pond or aeration equipment is available.
Scatter feed in 3 to 4 feet of water completely around the pond. Feed at the same time each day when oxygen concentration of the water is highest. This is usually around midday. Trucks with blowers or other mechanical feeders are desirable for large ponds.
Never feed more than 30 pounds per acre per day unless water is flowing through the pond or aeration equipment is available to prevent an oxygen depletion.
Self-feeders are good labor-saving devices for isolated small ponds. Place them so feed will be dropped in 3 to 4 feet of water. Fish learn to bump the underwater release and obtain feed. Avoid overfeeding by putting only the correct amount for 2 or 3 days in the feeder. Without auxiliary hand scattering of feed, self-feeders may cause a wide variation in fish sizes.
Before feeding each day, check the response of the fish by throwing out small amounts of feed; also, check self-feeders to see if they have been used. If fish fail to feed vigorously, something is wrong; stop feeding until you find and correct the trouble.
If you use sinking pellets, check feed consumption by placing a4- by 4-foot tray on the pond bottom in the feeding area before feeding. Lift the tray slowly an hour after feeding. If all the feed has not been eaten, reduce the amount of food.
To prevent weight loss and increase disease and parasite resistance, feed catfish held over winter. Self-feeders are helpful in winter, since at this season it is difficult to know when the fish are hungry. When the water temperature 6 inches below the surface is below 45°F, feed every other day at the rate of one-half of 1 percent of the estimated total weight of the fish in the pond. During warm weather feed each day at the rate of 1 percent of the weight when the water temperature is between 45°-60°F. In ponds holding brood fish, stock small forage fish such as fathead minnows (Pimepha/es prome/as) or other species to provide protein necessary for egg growth and to keep the males in good condition. If fatheads are not available, feed cut fish or liver.
Harvesting methods will vary from one fish farming operation to another. Some farmers use a "seine-through" technique that allows for a partial harvest three or four times each year. This method allows the farmer to "top off" the market size fish while the smaller fish pass-through the seine and remain in the pond for future growth. Other fish farmers may conduct only one operation for a total harvest at the end of the growing season. This is achieved by seining the entire pond or by draining the pond and concentrating fish in a harvesting basin.
Catfish ponds should be designed to facilitate harvesting operations. Ponds that have a firm, smooth bottom free from trees and stumps and gradually deepening to a harvesting basin are easily seined. Stretch the seine from bank to bank. A long rope attached to the bottom of each end makes the seine easier to haul. Trucks and tractors with winches are often used to pull long seines. In well constructed ponds, an experienced seining crew with good equipment can harvest 70 to 90 percent of the fish. Lower the water to concentrate the remaining fish in the harvesting basin.
Carrying fish from a pond to a tank truck is back-breaking labor. Mechanical equipment such as a power hoist mounted on a truck or tractor makes the job much easier.
Catfish being harvested and hauled are under considerable stress. Fish concentrated during the harvesting operation may suffer from oxygen deficiency and emergency aeration may be necessary to prevent losses. The digestive tract of fish should be empty when they are handled or hauled, so do not feed fish the day before harvest.
Harvest timing is important to the fish farmer. Regardless of the harvesting method used, harvest operations must be coordinated with processing plants, live haul markets, or other receiving outlets of the fish industry. Evaluate fully the available markets before starting a fish farming enterprise.