Feed Formulas and Feeding Methods for Cage-Cultured Common Carp
Cage culture of common carp adapts to a fairly wide range of waters. Cages can be set up in lakes, reservoirs and rivers; as long as the water depth is greater than the height of the cage, normal culture can be carried out, creating one ‘pond in the water’ after another. Compared with land ponds, the water is livelier and richer in oxygen, and its waste-flushing capacity is stronger, making it more suitable for intensive culture of a single species or multiple species, with high yields, easy management and easy harvesting. Now let us take a look together!
Common Carp Feed Formulas
1. Wheat bran 45%, soybean cake 40%, barley 10%, fishmeal 5%, with appropriate amounts of multivitamins, inorganic salts, lysine and methionine added; the feed conversion ratio is 2. This formula was provided by the Beijing Fisheries Research Institute.
2. Wheat bran 45%, fishmeal 30%, soybean cake 15%, barley 10%, with the same additives as in (1); the feed conversion ratio is 2. This formula was provided by the Beijing Fisheries Research Institute.
3. Soybean cake 50%, fishmeal 15%, wheat bran 15%, rice bran 15%, multivitamins 1%, inorganic salts and antibiotic processing scraps 1% each, binder 2%; the feed conversion ratio is 2.7. This formula was provided by the Shanghai Fisheries Research Institute.
Feeding Techniques for Cage-Cultured Common Carp
1. Feeding method: manual feeding is generally used, and where conditions permit a dedicated cage feeder can be used. After fingerlings are put into the cage, they need to rest for 2 days to adapt to the new environment of the cage. If the fingerlings were bred in cages and overwintered in this same reservoir, they can be fed the next day. At the start of feeding, suitable feed should be given according to the different sizes of the fish, so that the fish can eat appropriately and the amount of feed can be increased. The key to feeding is to train the fish to come up to the surface to compete for food. Generally 7 to 10 days of training is needed for common carp to form a conditioned reflex and develop the habit of competing for food.
2. Feeding amount: the feeding amount should be flexibly controlled according to the weather, water temperature and the feeding situation of the fish. Start feeding when the water temperature rises to 12°C; the number of feedings is generally 2 times a day. When the water temperature rises to about 20°C, feed 4 times a day. When the water temperature rises above 25°C, this is the period of vigorous feeding for common carp, and 5 feedings a day is appropriate. After September, the water temperature gradually falls again, so the number of daily feedings is gradually reduced to 4 to 3 times. Generally, the interval between feedings is about 3 hours. Under normal conditions, make sure the fish eat until they are "80% full".
3. Feeding rhythm: at the start of each feeding, feed little and slowly; when most of the fish have come up to compete for food, feed more and quickly; when most of the fish no longer come up to compete for food, feed little and slowly. Simply put, master the feeding rhythm of "slow, fast, slow". Stop once the fish have eaten until they are "80% full".
Living Habits of Crucian Carp
Crucian carp is a poikilothermic animal; its body temperature changes with the water temperature, and its activity capacity also varies with the water temperature. In spring and autumn, when the climate is mild and the water temperature moderate, crucian carp has a wide range of activity and is active in foraging. In summer, when the climate is hot, places exposed to the sun and shallow-water areas heat up quickly and the water temperature is higher, so crucian carp mostly inhabit shady places and deep-water areas.
In winter, when the climate is cold, crucian carp mostly swim and forage in sunny places and deep-water areas. On cloudy and rainy days, shallow-water areas lose heat quickly and the water temperature is low, but deep-water areas are somewhat warmer, so crucian carp mostly move about and forage in deep water. On sunny days, the shallow water layer is warmed relatively quickly by sunlight and the water is somewhat warmer, so crucian carp mostly swim and forage in sunny places where the water is deep.
Preparation for Crucian Carp Culture
1. Pond conditions: a pond of 3-20 mu and 2-3 m deep is best, sheltered from the wind and facing the sun, non-leaking, with convenient water intake and drainage and a flat bottom. The pond should have three items of equipment: first, a feeder; second, an aerator, with one 3 kW unit for every 3-5 mu of water surface; third, a large dragnet, to prepare for later sampling and sales. The pond should be thoroughly cleared of silt. About 15 days before the fingerlings are put in, clear the pond with quicklime and keep the water in a lean state.
2. Culture model: from the current situation, the most economically beneficial model is the "80:20" model of pond culture with crucian carp as the main species, that is, at harvest, 80% of the yield is silver crucian carp and 20% is "fertilizer-water" fish species that serve it. Farmers can choose a suitable crucian carp variety for culture according to local market acceptance, but the fingerlings should as far as possible come from improved crucian carp farms holding seed production licences. Fingerlings should be purchased in advance and kept temporarily in one or two ponds for 15~30 days, during which the fish can be examined and appropriate disease prevention and treatment carried out.
3. Feed preparation: the protein content of feed for market-size fish is about 30% or more, and the feed particle size is 2-3 mm, not exceeding 3.5 mm at most; both pelleted feed and extruded feed can be used.
Speaking of crucian carp, I think everyone is very familiar with it; it can be seen everywhere in vegetable markets and supermarkets. Crucian carp has a very large market share, because crucian carp is not only delicious but also relatively cheap. It is truly a good thing of excellent quality at a low price.