Pond culture of black-tailed near-red carp has increased yields using modern microporous aerators and micro-ecological preparations
Liu Qin
Black-tailed near-red carp, commonly known as black-tailed carp, black-tailed, etc., belongs to the genus of near-red carp in the subfamily Cyprinidae, and is a unique economic fish in the Yangtze River system. From 2013 to 2019, our county applied modern microporous oxygenation technology, used microbial preparations to regulate water quality, and fed the special puffed material for the carp throughout the process to carry out high-yield and efficient breeding experiments of black-tailed near-red carp, and achieved good social and economic benefits. The test results are summarized as follows for reference in the high-yield culture of adult blacktail near red carp.
1 Materials and methods
1.1 Pond conditions
There were 2 test ponds, each with an area of 0.4hm2 and a total area of 0.8hm2. The pond is rectangular, east-west oriented, the bottom of the pond is flat, the silt is about 30 cm thick, and the water depth is 1.8 to 2.2 m. The water source of the experimental pond aquaculture is Wuchang Lake, the water quality is fresh, there is no pollution, the implementation of high irrigation and low drainage, the inlet and drainage system is separated independently. The test pond is equipped with a set of 2.2 kW microporous aeration equipment, 18 aeration plates are set up in each pond, and 2 sets of 90W automatic feeders are set up in each pond.
1.2 Preparation of fingerlings before stocking
15 days before stocking, quicklime 2250kg/hm2 with water clear pond, 3d after the application of fully fermented organic fertilizer 1500kg/hm2, while sprinkling with chlorine dioxide whole tank disinfection, the next day with 90% crystal enemy insect poison to kill predators. 7 days before the stocking of fish fingerlings, depending on the water quality, appropriate topdressing of biological fertilizer or inorganic fertilizer to ensure that the fingerling fertilizer is in the underwater pond. The day before stocking is filled with fresh water to make the pond water 80 to 100 cm deep.
1.3 Fingerling stocking
The scales of the black-tailed near-red carp are small and loose, and the stress response is strong, and the fish species should choose to be released in the cold season after the Spring Festival. A total of 482 kg of winter fillet fingerlings with a size of 15-18 cm were stocked in the test pond, with a total of 26,420 fish and a stocking density of 33,025 fish/hm2. Fish species are disinfected with 3% to 5% salt water bathing before entering the pond, and on the second day, the water body is disinfected with povidone iodine whole pond.
1.4 Feed feeding
Before and after the Qingming Festival, the water temperature is 13 ~ 15 °C, the puffed feed is started, the crude protein content is ≥ 36%, the particle size is 1.5mm, and the fish species are fed less, and after the normal feeding of the fish species, the whole process is fed using the puffed feed mechanized feeding. According to the principle of "four certainties", feed 3 to 4 times a day, reduce feeding or not feed on rainy days. Adhere to the "two-headed fine, middle coarse", 1 month after the opening of the diet and about to stop 1 month, feed the crude protein content of ≥ 36% of the puffed feed, the rest of the time the feed crude protein content of 30% ~ 32% can be. According to the growth of the fish body, the feed feeding amount is controlled at 3% to 5% of the fish's body weight, and the specific feeding amount depends on the feeding situation of the fish.
1.5 Water quality control
First, open the microporous aerator. Use the time control switch to set the opening time of the microporous aerator, and always keep the dissolved oxygen in the test pond above 5mg/L. Under normal conditions in the high temperature season, it opens for 2 to 3 hours at noon on a sunny day. Open at night (from midnight to sunrise) for 6 to 8 h, and on rainy days, depending on weather conditions, the opening time will be increased or opened all day. The second is the use of microecological preparations. Microbial preparations such as EM bacteria and Bacillus are used regularly, and once in 10 to 15 days during the high temperature season. The third is to fill new water. Regularly fill new water, timely apply biological fertilizer according to the water quality, keep the water fresh, live, tender and refreshing, and the transparency is 30 to 40cm. The fourth is insecticidal disinfection. During the breeding period, regular insecticide and disinfection are carried out with avermectin and povidone iodine, and fish disease prevention is implemented, generally once a month.
1.6 Day-to-day management
The test pond is managed by special personnel, the breeding file is established, the breeding log is done, and the pond is patrolled every morning and evening to record the weather, water temperature, feeding and feeding. Regularly detect the physicochemical factors such as dissolved oxygen, pH value, NO3-, NO2-, H2 S and other physical and chemical factors in the water body.
2 Results and analysis
2.1 Yield
Due to the high hooking rate of black-tailed near-red carp and its extremely easy fishing, the test pond was in the fishing area of Wuchang Lake Special Aquatic Breeding Farm in Wangjiang County, Anhui Province, starting from October 1, and opened for fishing on weekends, until the end of the year, a total of 7836kg was harvested. At the end of the year, the one-time catch and sale was 4723 kg, the fishing and starting of the total adult fish was 12559 kg, the yield was 15698.75 kg/hm 2, the average weight of the individual was 0.475 kg/tail, and the net weight gain of adult fish in the pond was 12177 kg. The test pond was fed a total of 15,000 kg of puffed feed with a bait coefficient of 1.24.
2.2 Benefits
The first is the cost of breeding. Feed 96000 yuan, fish fingerlings 26420 yuan, fish medicine, fertilizer 2840 yuan, biological preparations 6300 yuan, pond rent 4800 yuan, electricity costs 1800 yuan, labor and other 2000 yuan, a total of 140160 yuan, investment of 175200 yuan / hm 2. The second is the sales income of adult fish. The total income of adult fish fishing is 36 yuan / kg, and 282096 the total income of adult fish is 20 yuan / kg, with a total income of 94460 yuan, and the total income is 376556 yuan. Third, the net income is 236396 yuan, the net profit is 295495 yuan / hm 2, and the input-output ratio is 1:1.69.
3 Conclusions and discussion
3.1 Black-tailed near-red carp in Anhui has good promotion prospects The black-tailed near-red carp has tender flesh, delicious taste and high nutritional value. Fast growth rate, low oxygen resistance, strong disease resistance, easy to domesticate breeding and fishing, and has the characteristics of high hook rate and easy fishing, which is welcomed by the majority of consumers. The test results show that the introduction and promotion of the black-tailed red carp in Anhui has good market development prospects and is also a good breed for recreational fishing.
3.2 Microporous aerators and microecological preparations increase yields
The experimental black-tailed near-red carp pond culture applies modern microporous oxygenation technology, the use of microbial preparations to adjust water quality, the whole process of feeding full-price squid special puffed material, can make the pond yield and efficiency significantly improved. The test achieved a yield of 15698.75 kg/hm2 and an average individual weight of 0.475 kg/tail, which was compared with conventional aquaculture in 2012, and achieved a doubling of pond yield and benefit.
3.3 High economic benefits
The test was carried out in the provincial recreational fishery demonstration base, the test pond fishing production accounted for 62% of the total production, the fishing price of 36 yuan / kg, pulling up the average sales price of pond commercial fish, aquaculture units should take into account this factor in the introduction and promotion. It should be pointed out that the test applies the "two micro" technology, feeds the puffed feed throughout the process, obtains better breeding technical parameters, invests 175200 yuan / hm 2, and the net profit 295495 yuan / hm 2, which can be described as high input, high output and high efficiency. In the case of no fishing business, the production unit sells all commercial fish on the market, the sales price is calculated according to 20 yuan / kg, the profit is 111020 yuan, and the average profit is 138775 yuan / hm 2, and still can achieve good economic benefits. In view of the fact that the black-tailed near-red carp is a pelagic fish, eating miscellaneous, fertile water, feeding on some zooplankton, in order to increase economic benefits, in the actual application and promotion, it can also be appropriately raised with silver carp, yellow jawed carp, crucian carp, etc., which not only regulates the water quality, but also makes full use of the water body space, increases the output of the pond, and correspondingly increases the input-output ratio.