The market benefits in different periods are different. When is the best time for grass carp culture?

Grass carp is one of the four largest freshwater fishes in China. Its meat is sweet and has the effect of warming the stomach. Its gallbladder tastes bitter and cold, and it has the functions of lowering blood pressure, resolving phlegm and slightly relieving cough. Grass carp (Ctenopharyngodon idellus) is a typical herbivorous fish, which lives in rivers and lakes in plain areas, and its parents have the habit of spawning upstream during the breeding season. Grass carp grows rapidly, has a wide range of feed sources, and has good breeding benefits. Grass carp is a large-scale economic fish with rapid development. The second to third instars grow fastest. Under pond culture conditions, the growth rate of grass carp population is generally 50-60g in the first year, 500-750g in the second year and 2-3kg in the third year, so the grass carp culture cycle is 2.5 -3 years.

After overwintering, the water quality of fish ponds is generally aging and slightly acidic. Therefore, when the water temperature in the fish pond gradually rises and stabilizes above 13℃~ 15℃, the water quality of the fish pond should be regarded as replacing the whole fish pond with 1/3 fresh water, and the water level should be lowered appropriately to make the water temperature rise rapidly. When the weather is clear, start the aerator 1-2 hours at noon, and use quicklime or microbial agents to improve the water quality of the fish pond according to the situation. Grass carp varieties should choose individuals who are golden in color, intact in appearance, lively and robust, and weigh about 100g. Because grass carp bleeding and enteritis are easy to be infected, it is best to choose 2-year-old fry. Fish should be disinfected before being put into the pond. When stocking, fish are soaked in 3% salt water to immunize grass carp.

When the fingerlings are released, firstly, there are 250 grass carp, each mu 150 ~ 200 grams. Compared with high-density and large-scale stocking, this stocking method can greatly reduce the cost of fish farming, saving 50% ~ 73%; On the other hand, it also avoids the phenomenon of dead fish in the flood pool when the amount of fish in the water is too high in high temperature period. The other is 800 ~ 1000 fish per mu, whitebait 100 fish and herring 15 fish, with individual specifications of 250 ~ 500g. Carp are not matched or less matched, so avoid grazing with grass carp. The content of protein in feed is an important factor affecting the economic benefit of grass carp culture. Practice has proved that when the feed protein content is about 30%, it can not only ensure the rapid growth of grass carp, but also reduce the feed cost, and the breeding benefit is the best.

Intensive aquaculture ponds should be strictly observed? Qualitative, quantitative, timing and fixed point? Feeding. From mid-March to mid-May, feed them regularly 2-4 times a day, from June to mid-August, 3 times a day, and from mid-August to 10, 4 times a day. From June, feed green feed 1 time every day, and the feeding amount should not be too large, and it is appropriate to feed it seven or eight times to prevent satiety or hunger. Grass carp is fierce and overeating. If you feed too much at a time, the feed will easily swell and die in the intestine. Generally, the daily intake is 1.5% ~ 1.8% of the grass carp's weight, and it is divided into three times. In order to prevent individual growth polarization caused by uneven feeding, the diameter of granular feed is 4 mm, and the feeding time should not be less than 45 minutes each time, so that all grass carp can get as much feed as possible.