Feeding method of grouper
1, seedling cultivation
(1) fry stocking: when the total length of fry is 2.5-5cm, fry are stocked in a plastic frame (table cover), and the stocking density is 500- 1000/frame; when the total length is 5-9cm, fry are stocked in a small plastic cage, and the stocking density is1000-/. When the total length is 10-20cm, it is directly put into a circular cement pool of10m3 for feeding. When stocking seedlings, strict screening and disinfection must be carried out, and seedlings of different sizes should be raised separately. When feeding with plastic frames and small cages, the plastic frames and small cages are placed in a cement pool, and the pool is inflated, but the frames and boxes are not inflated.
(2) Bait feeding: During the feeding period of fry, the main bait is chilled small miscellaneous fish and shrimp. When the seedling is 2.5-5 cm long, feed it 6 times a day, 3 times in the morning and 3 times in the afternoon, and the feeding amount is 12%-20%; The total length is 5-9 cm, and it is fed four times a day, twice in the morning and twice in the afternoon, and the feeding amount is 8%- 12%; During the whole length10-20cm, it is fed 2-3 times a day, 1-2 times in the morning and afternoon, and the feeding amount is 4%-6%. In the period of 2-5 cm, the chilled small miscellaneous fish and small miscellaneous shrimp can be made into minced fish for feeding, and the chilled small miscellaneous fish can be cut into blocks for feeding according to the diameter of the fingerlings over 5 cm, and can be directly fed when the shrimps and small miscellaneous fish larvae are used as bait.
(3) Water quality management: During the breeding period, the amount of water exchanged should be determined according to different seasons and different bait varieties. Under normal circumstances, the water should be changed in large rows on dry land after each feeding, and the residual bait and feces at the bottom of the pond should be removed in time, and continuous aeration and running water should be maintained for 24 hours. When the water temperature is higher than 25℃, the water exchange rate is 8- 10 cycles, and it is usually 4-5 cycles.
(4) Separate breeding and screening of fry: Killing each other is the nature of Tiger Spot, which mainly occurs in the period of 1.5- 10 cm. Individuals of different sizes have a strong tendency to attack and kill, and the result is that the smaller ones are swallowed and the larger ones are mutually assured destruction, so it is necessary to screen them once every 2-3 days in the breeding process to keep them in the same breeding pond. Breeding and screening of fry can be combined with cleaning bellows or dumping pond, and the operation of screening and dumping pond should be serious and brisk to avoid fish injury caused by improper operation.
(5) Overwintering of fry: Before overwintering, management should be strengthened, and sufficient and good bait should be put in, so that the fry can have strong physique and overwinter smoothly. When the water temperature is lower than 18℃, heat preservation measures should be taken to keep the water temperature above 20℃ and the fluctuation range of water temperature difference should not exceed 2℃. During the overwintering period, the feeding amount is 4%-6% of the fish's weight, and the feeding amount is 1-2 times a day, and the convection water exchange volume is 2-4 cycles, and continuous aeration is maintained. Tiger spot is a tropical and subtropical fish, which is cold-averse. The suitable temperature range is 15-35℃, and the highest and lowest lethal temperatures are about 12℃ and 38℃ respectively. The fry propagated in that year can't be cultured and marketed in that year, and the specifications can reach150-200g after wintering.
2. Adult fish culture
(1) fry stocking: In April, when the water temperature in the natural sea area is stable at 20℃, the fish in the heat preservation shed can be moved to the abalone culture pond. Before the larvae enter the pond, the culture pond is washed and disinfected with sodium hypochlorite containing available chlorine 10%, washed with clean seawater for several times until the residual chlorine disappears completely, and then water is added to1.2m, and then the larvae are moved into the pond. When the seedlings enter the pond, they should take a medicinal bath, which can be 5- 10 mg/L povidone iodine (containing available iodine 10%) and 1-2 mg/L Ueno yellow medicinal bath for 3-5 days, once a day, for 2-3 hours each time.
(2) Breeding density: Tiger Spots have the ecological habit of clustering, low oxygen consumption and little activity after satiation. Therefore, it is suitable for intensive high-density culture. Generally, the fry with individual weight150-200g have a stocking density of 200-300 fish/m2. The individual weighs 200-350g, and the density is150-200g/m2; The individual weighs more than 500 grams and the density is 30-50 tails/m2. In order to promote the growth of fish, the breeding process should be based on the individual size of fish species, and the pond should be screened and inverted once every 30-40 days. The emptied pond should be strictly washed, disinfected and rinsed in dry land before use.
(3) Bait feeding: artificial breeding of grouper brown spot mainly uses small miscellaneous fish, shrimps and crabs as bait. At present, adult fish are generally fed with fresh small miscellaneous fish and shrimps or soft pellet feed made of premix of fresh small miscellaneous fish and grouper produced in Taiwan Province. When fresh small miscellaneous fish is used as bait, the daily feeding amount is 8%- 12% of the fish weight, and when soft pellet feed is used as bait, the feeding amount is 8%-12%.
(4) Changing water for cleaning: after feeding in the morning and afternoon every day, the water is changed greatly, and the method of cleaning the dirt and residues on the wall, bottom and air-filled pipe while draining water is adopted. After lowering the water level to about 40 cm, convection 1-2 hours until the water quality is fresh, and then add water again to the original position.
(5) Disease control: In the process of industrial breeding of tiger spot, it is necessary to prevent parasites such as rotifer, cucurbit and valvuloid, bacterial diseases such as Vibrio and Edwardsiella, and nutritional diseases, especially the breeding period of fry is very important, so special attention should be paid to the disinfection and cleaning of the breeding environment, and the cultured fish should be disinfected and bathed in fresh water regularly.
Feeding and management techniques of grouper
1, adhere to the daily management of disease prevention, supplemented by treatment. Boss Guo's pond is a low pond, and basically 50 cm of water will be replaced every high tide; When the water quality is poor, it is also treated by changing water. Sprinkle anti-stress drugs before entering the water to improve the resistance of fish; Disinfect the water body after entering the water to prevent pests and diseases on a regular basis. Water bodies will also be disinfected after rainy days or typhoon weather. The more important link in the daily management work is to carefully observe the feeding situation of fish when feeding, and if there is a bad feeding situation, change the water in time and adjust the water quality. Another acre of pond water is probably equipped with an aerator, which has done a good job in aerating and transferring water.
2. Choose high-quality feed and pay attention to cost performance. At present, there are many feed brands in the market, and the price and quality are uneven. We should not only look at whether the price is cheap, but also pay attention to the effect of a feed from many aspects, such as digestibility, growth rate and bait coefficient. Some farmers only care about the low price, but they don't know that although the price is low, the overall bait coefficient is high because the production technology and raw materials can't keep up, and the final breeding cost may be high.
Under the influence of the market downturn, some grouper feeds are willing to reduce the feed quality and price promotion in order to seize the market. The optimal series of grouper feeds in the world can not only maintain the stable quality, but also continuously optimize the quality, which can make the fish digest better, make the cultured fish healthier in color and shape, and greatly promote the breeding profit of grouper in two years.
3. Feeding management. Due to the different ways of taming fry in different seedling farms, the fry bought by boss Guo this year belong to? Eat and sink? The habit of. When feeding, the fish don't swim out of the water to grab the material, but can only see the fluctuation of the water surface, but can't see the fish eating, which brings many difficulties to the feeding, and inexperienced farmers may have insufficient feeding or excessive feeding, resulting in waste. For this problem, Mr. Guo thinks that to choose feed with good slow sinking effect, just feeding grouper can solve this problem well.
When feeding, as long as you see the feed rolling up and down, it shows that the fish are grabbing the material, which is very convenient. Many farmers find this unique advantage of slow sinking when feeding the upper grouper in cold weather, which is of great help to feeding management. In different growth stages, it is best to use different materials: before seedling stage 15 cm, choose to use the more comprehensive nutrition of the upper gentian series to lay a nutritional foundation; After15cm, when the feeding amount increases, a more economical upper-upper optimized series of grouper can be selected. Feeding methods are also particular: feed 3 meals a day before 10 cm, and feed at 5% of body weight; 10- 17 cm feed 2 meals a day, and feed 3-4% of body weight; 17 cm, feed 1 meal every day, and stop feeding 1 day for 3-4 days.
Transportation management method of grouper
Water quality technology requires that water quality is one of the most important factors in the transportation of live fish. The seawater used to transport live fish must be fresh, free from pollution, with sufficient dissolved oxygen and low organic matter content. Therefore, it is best to use clean seawater that has been precipitated, disinfected and filtered in the nursery during transportation.
Water temperature technology requires that the optimal water temperature for grouper transportation should be kept at around 16℃, which can make grouper in a semi-anesthetic state. If the water temperature is too high, it will accelerate the metabolism of fish, cause the deterioration of water body and cause death; If the water temperature is too low, it will freeze the fish. Therefore, controlling the temperature of storage and transportation water is one of the important factors for the success or failure of transportation.
Dissolved oxygen technology in water requires that the survival rate of grouper transportation can only be ensured by ensuring sufficient dissolved oxygen in water (generally reaching 8 mg-10 mg/l). There are four common oxygen supply methods: (1) fan oxygen supply; (2) molecular sieve machine for oxygen supply; (3) oxygen supply by oxygen cylinders; (4) Liquid oxygen supply has its own advantages and disadvantages. You can choose the appropriate oxygen supply method according to your specific conditions.