How many jin can a carp gain in a year, and what feed should be given for high yield?

Carp, with the Chinese aliases li guaizi, lizi, maozi, and red fish. It usually inhabits the bottom layer of rivers, lakes, reservoirs, and ponds where aquatic plants grow densely, feeding mainly on benthic animals. So how many jin can it usually gain in one year? What feed should be given? How should it be raised for high yield? According to Master Su, a carp farmer in Yueyang, Hunan, this depends on how big the carp is. When very small, it grows very little in a year; at 3-5 years of age, it can gain about 2 kg in a year; when larger still, the gain decreases again, and it also depends on what feed is given.

What feed should be given to raise carp?

Carp is an omnivorous fish. Leftover rice, leftover dishes, fruit peels and the like can be mixed with about 10% animal-based feed such as animal offal, apple snails, maggot pupae, and earthworms to make pellets for feeding. Its feed protein content should reach about 35%, and fat 5%-8%. Feeding should adhere to the “four fixeds”; generally feed twice a day, once in the morning and once in the afternoon. The feeding amount depends on water temperature, weather changes, and the fish's feeding situation. It is roughly 2%-10% of the fish's body weight, and it is best if eaten within 20-10 minutes.

How should carp be raised for high yield?

1. They generally reach sexual maturity at two years of age, and some individuals can also mature at one year. The spawning season varies by region; spawning can occur from March to August (with April to June as the peak period), and they are a batch-spawning type. Spawning grounds are mostly in shallow lake bays or river bends with dense aquatic plants. The eggs are strongly adhesive and firmly attach to aquatic plants right after spawning. Fecundity varies with age and individual size, ranging from 150,000 to 800,000 eggs. After the eggs are laid, they can hatch into fry after 4-6 days at a water temperature of 15-20°C.

2. Selection criteria: good body shape, strong activity and no injuries, a body length to body height ratio of 3:1, and typical breed characteristics. Female fish should be at least 2 winters old and weigh 1.5 kg, and male fish at 2 winters old and over 1 kg are better. Carp that are maturing for the first time or in the aging period have poorer fecundity and egg quality, so they are not suitable as brood fish.

3. Rearing: brood fish cultivation ponds of 1-2 mu, with a water depth of about 1.2 m, sheltered from wind and facing the sun, with convenient water intake and drainage, and 150-200 kg stocked per mu. During artificial breeding, males and females should be separated to prevent them from mating and spawning on their own. Before stocking, disinfect with quicklime or bleaching powder.

4. Management: intensify brood carp cultivation, and feed high-protein feed such as soybean cake, silkworm pupae, and fish meal. In recent years, some manufacturers have developed brood fish feed; this feed is rich in ve and other vitamins, can promote development and improve stress resistance, and has good effects. At the same time, during the rearing process, attention should be paid to regulating water quality, often adding fresh water, and maintaining slight water flow to stimulate gonadal development.

5. Start feeding early. The earlier the fry start feeding, the earlier their growth starting point, and the better their growth. Efforts should be made to transition as early as possible and smoothly to feeding with complete formula feed; vigorously focus on the early stage of the fast-feeding fry (especially from the inch size to 25-30), when growth is particularly fast, both body length and body weight increase quickly, and more feed is needed. At this time, feeding should be strengthened; some fishermen have a feeding rate of more than 10% at this stage; feeding should adhere to the “four fixeds” of fixed quality, fixed time, fixed location, and fixed quantity, and be carried out according to the feeding rhythm of the fry.

Appendix: Stocking models with carp as a secondary species

1. Model mainly based on grass carp or blunt snout bream: grass carp or blunt snout bream 60%, carp 15%, silver carp and bighead carp, and crucian carp together 25%, suitable for areas with good water sources and more grass feed.

2. Model mainly based on silver carp and bighead carp: silver carp and bighead carp 50%, carp 15%, grass carp, bream, and crucian carp 30%, suitable for relatively fertile water bodies.

3. Model mainly based on channel catfish: channel catfish 60%, carp 10%, silver carp and bighead carp, and bream 30%.

4. Model mainly based on crucian carp: crucian carp 60%, carp 10%, grass carp 10%, silver carp and bighead carp 20%