Key technical points to grasp in the intensive culture of black carp
Black carp, also known as snail green, is one of the conventional fish species cultured relatively early in our country. After years of summarized experience, farmers have relatively mature technology, but several technical points still need to be grasped during the culture process.
Technical point one: intensive culture mostly adopts the model of polyculturing large black carp with small black carp. The recommended stocking standard is 190 to 220 fish of about 3 to 4 jin each per mu, 30 jin of small fry at about 6-10 tails per jin, plus 500 to 800 crucian carp of about 1 liang each, and 150 jin of silver carp and bighead carp. This stocking model can fully utilize and mobilize the comprehensive production capacity of the pond, increase output, improve benefits, and reduce diseases.
Technical point two: feeding model. After many years of culture, the feed has undergone repeated practice and adjustment, and changing from the previous sinking feed to the current extruded feed is more suitable. First, it increases the utilization of feed and reduces feed waste; second, it reduces pollution to water quality; third, it increases output and benefits. The Tongwei black carp feeds 8923, 8926, etc. commonly used on the market are relatively ideal extruded feeds for black carp. Experience shows that in spring and autumn, when black carp grow most suitably, using high-grade black carp feed can increase yield per mu and improve the market size. Especially in recent years, when prices for large commercial fish are better, using famous high-grade black carp feeds such as Haid and Tongwei makes culturing large fish more profitable.
Technical point three: water quality management emphasizes appropriate fertility. If the water is not fertile, the fish do not eat well, and ultimately they do not grow well either. A certain degree of fertility can first provide part of the natural food, and at the same time, water with abundant algae has higher dissolved oxygen. In water with high oxygen, black carp are more conducive to rapid growth. Ponds are generally fertilized around Qingming, and the fish feed especially vigorously. At the same time, to ensure the water remains fertile without becoming old, quicklime and microbial preparations must be used irregularly from May to October to regulate water quality.
Technical point four: disease prevention and control should strengthen prevention. Black carp have relatively many diseases. In the first half of the year, insect pests and bacterial gill rot are the main problems, while in the second half of the year, hemorrhagic disease is the main problem. Before Qingming and around Mid-Autumn each year, strict disinfection and parasite control should be carried out, and prevention work should be done especially well during high-temperature periods. Currently popular vaccines can effectively prevent the occurrence of black carp diseases, and the protective power of injection vaccines reaches more than 90%.