Key Technical Points for Fingerling Rearing in Carp Farming

Summer fry fingerlings must be selected from those that are disease-free and uninjured, robust in constitution, lively in movement, and uniform in size. Fingerling rearing generally adopts mixed culture of 2 to 3 species of fish, but with one species as the main one. In a pond with carp as the main cultured fish, stock 6,000 to 8,000 summer fry per 667 sq m, together with 20% silver carp and grass carp or 20% bighead carp and grass carp, and the size at harvest can reach 15 to 18 cm; if 8,000 to 10,000 summer fry are stocked per 667 sq m, the size at harvest can reach 13 to 16 cm.  

During the fingerling rearing process, natural food in the water alone cannot meet the growth needs of the fingerlings, so artificial feeding and fertilisation are necessary. When the fingerlings are first stocked in the pond, the daily feeding amount is 1 to 1.5 dry grams per 667 sq m, gradually increasing to 2.5 kg thereafter. The principle of “four fixeds” must be followed, feeding twice a day: at 9-10 am and 4 to 5 pm. The feed must be guaranteed in quality, and prevented from becoming mouldy and deteriorating. It is placed on a round or square feeding platform of 1 sq m made of bamboo strips. The feeding platform is fixed with stakes in shallow water at a depth of 30 to 40 cm, with l to 2 feeding platforms per 667 sq m. The amount of fertiliser applied should be moderate, maintaining good water quality that is fertile yet fresh. Manure can be applied at 150 to 200 kg per 667 sq m every 10 days. If organic fertiliser is insufficient, chemical fertiliser can be applied as a top dressing, with 1.5 to 2.5 kg of urea and 3 to 5 kg of superphosphate per 667 sq m every 10 days.  Daily management consists of one pond patrol per day to observe the water colour and the activity of the fingerlings. The feeding platforms must be cleaned frequently, and weeds at the pond edge removed. The feeding area is disinfected with bleaching powder every 10 to 15 days. When fingerling rearing reaches August and September, fingerlings of different sizes should be divided into separate ponds for rearing. To improve the water quality of the fish pond, add water twice a month in places with sufficient water sources. When the water temperature drops to about 10°C in early winter, choose fine weather and concentrate the fingerlings separately by species and size in deeper ponds for overwintering. The overwintering pond should be sheltered from the wind and facing the sun, with a water depth of 1.5 to 2 m. Each 667 sq m of water surface can hold 750 to 1,000 kg of fingerlings. When combining ponds, operations such as seining, sorting the fish by sieving, counting and transferring between ponds must be done carefully and meticulously. In terms of management, freezing and oxygen deficiency must be prevented.