High value soft-shelled turtle culture depends on technology

Soft-shelled turtles are egg-laying reptiles, amphibious life. Soft-shelled turtle is rich in nutrition, not only a delicacy on the table, but also a widely used nourishing medicine, which has the effect of clearing heat and nourishing yin, calming the liver and extinguishing wind, softening and dispersing knots. The benefit of soft-shelled turtle culture is better, this issue specially edited a group of soft-shelled turtle culture techniques for farmers' reference.

Cultivate parent soft-shelled turtle

15 days before the breeding of parent soft-shelled turtle in the pond, the pond and canal should be cleaned and disinfected. The sundries and dirt should be removed first, and then thoroughly disinfected with medicine to kill the wild miscellaneous fish and harmful pathogens.

The number of mixed culture of parent soft-shelled turtle is large and the activity ability is strong, so the density of mixed culture should not be too large. Generally, the amount of mixed culture should be controlled within 45 kg per 100 square meters. In order to stabilize the water quality of the parent turtle pond, a small amount of silver carp, bighead carp and crucian carp can also be cultured in the parent turtle pond, each with a capacity of 45 fish per 100 square meters.

Feeding and management should provide good living conditions for parent soft-shelled turtle and increase the fecundity of parent soft-shelled turtle. One is to prolong the growth period and spawning period of parent soft-shelled turtle as much as possible. Because the parent soft-shelled turtle has the habit of hibernating, the time for growth and spawning is relatively short in a year. If some artificial measures are taken to cover the plastic greenhouse or warm up culture in late autumn or early spring, the spawning time of the parent soft-shelled turtle can be prolonged, even spawning throughout the year.

The second is to do a good job of bait feeding. Soft-shelled turtles like to eat fresh animal bait, such as small fish and shrimp, snails, mussels, maggots, earthworms, insects and so on. These live baits are nutritious and should be fed as much as possible. If there is no fresh bait, the leftovers after slaughtering of livestock and poultry are also the bait that soft-shelled turtles like to eat, but can not be fed more. When breeding parent soft-shelled turtle, it is best to use artificial bait. Feed should be given at a fixed time and at a fixed point, and should not be fed with moldy and deteriorated bait. The appropriate feeding amount should be finished within 2 hours after feeding.

The third is to regulate water quality and prevent the occurrence of diseases. Parent soft-shelled turtle has more feces, which can easily deteriorate the pond water. It is necessary to change the water regularly and disinfect it at the dose of 15 grams of quicklime per cubic meter to keep the pond water fresh. It is also necessary to clean up the leftovers and feces of the bait table in time to prevent parent soft-shelled turtles from getting sick by eating spoiled leftovers.

Mating management

Soft-shelled turtle is a multiple spawning animal, the ovary development of the same female soft-shelled turtle varies successively, and there are often 3 or 4 groups of eggs of different sizes and different maturation stages. These eggs continue to mature, so their fertilization is ongoing. The male soft-shelled turtle can mate and ejaculate many times, and the sperm of the male soft-shelled turtle enters the female fallopian tube through male and female mating, which can keep alive and have the ability of fertilization for more than half a year. Therefore, in the case of monoculture, the eggs laid in the second reproductive season can still be fertilized and hatched by the female soft-shelled turtle mated before overwintering in that year.

From this point of view, the soft-shelled turtle does not have a fixed period of estrus, but the mating peak is after awakening in spring and before hibernation in autumn. Every year, when the water temperature rises above 20 ℃, sexually mature parent turtles begin to mate, a move that lasts until August.

Mating of parent soft-shelled turtles usually takes place in the water at night, so it is not easy to find. Female and male parent soft-shelled turtles dive and swim in the water before mating. Male soft-shelled turtles chase female soft-shelled turtles in the shallow water by the pool, and then slowly crawl and bite each other's skirt edges. Finally, male soft-shelled turtles crawl on the back of female soft-shelled turtles to mate. The back skirt of male soft-shelled turtles vibrate slightly for 3-5 minutes, and then dive into the water. After mating, the female and male parent soft-shelled turtle are fertilized in vivo.

Increase the number of eggs laid

The ratio of male to female should be appropriate in the soft-shelled turtle pond, while more male soft-shelled turtles affect the mating of parent soft-shelled turtles and reduce the fertilization rate. In general, the ratio of female to male is (3: 4): 1. If the male soft-shelled turtle in the pond is strong and large, the number can be less. On the contrary, the number of male soft-shelled turtle should be increased. If more claw marks are found on the back of the female soft-shelled turtle in the pond, it means that there are too many male soft-shelled turtles.

Female soft-shelled turtles with sufficient protein feed need more protein and calcium to lay eggs. In order to meet the needs of spawning, snails, clams, small fish and shrimp must be supplied regularly, quantitatively and at a fixed point.

Do a good job in water quality management to ensure that the soft-shelled turtle pond water is pollution-free, moderate fertility, light green or tea green. The transparency of the water is 25cm to 30cm, so there are many microbes in the water. If the water is too thin, you can sprinkle fresh human feces and urine or accumulate bar manure on the pond bank to let the fat water flow into the pool. The depth of the water is moderate to raise the water temperature. Change the water once a week and keep 1x10 of the pool water when changing the water.

Tidy up the spawning ground is also the soft-shelled turtle "sun back" field, before spawning should be flattened, spread 40-50 cm thick fresh sand, and keep moist.

Keep soft-shelled turtle pond quiet when mating and spawning soft-shelled turtles are very afraid of sound interference. Therefore, in the breeding season, it is necessary to remove the natural enemies in the turtle farm in order to reduce interference and avoid the harm of natural enemies.

To increase the lighting time, it is appropriate to install electric lights on the water surface of the soft-shelled turtle pond and turn on the lights at night, which can not only increase the lighting time, but also induce insects for the soft-shelled turtle to eat, killing two birds with one stone.

Breeding management

From 6 to 12 hours after the soft-shelled turtle eggs were ovulated, the soft-shelled turtle eggs were yellowish and translucent, and then the white spots (animal poles) began to appear, and the white spots expanded to a round area of 0.5 cm in diameter at about 24 hours, and the white area expanded from 2 to 96 hours in the eggshell, and then the white area basically stopped expanding.

After about 10 days, the white surface of the shell expanded rapidly, and the yellowish part shrank. In the light, there were blood filaments in the eggs. The unfertilized eggs could not see the blood filaments, so they should be picked out and no longer hatched.

About 15 days, the white part of the shell continued to expand, to the light, the blood filament distribution area expanded, the rest of the transparent.

After about 20 days, the shell surface is more than half white, and the transparent part (plant pole) becomes darker in color. Looking at the light, you can see a large number of blood filaments, black spots and shadow. The shadow is the embryonic head, about 1 cm in diameter, and can move, sometimes in the plant pole. Sometimes between the animal pole and the plant pole.

About 25 days, the white area of the shell surface is more than 60%, and the egg embryo shows a dark shadow in the light, which is more obvious than before.

In about 30 days, the shell surface is more than 70% white, and the plant is darker and redder. In view of the light, the embryo is basically formed and there is activity.

About 35 days, the shell white continues to expand, the plant is extremely smaller, the diameter is only about 1 cm, the color is darker, showing deep purplish red, to the light, it can be seen that the embryonic head has obvious telescopic activity.

After about 50 days, the embryonic development of soft-shelled turtle eggs was completed, the polar boundary between animals and plants disappeared, and the whole soft-shelled turtle eggs were opaque white. The temperature and humidity are suitable to break out of the shell, and the shell time is mostly in the evening and before and after dawn.

Summer management

Since the middle and late July, the weather began to stabilize gradually, the temperature rose, the soft-shelled turtle culture work really entered the normalization, the breeding disease situation improved slightly, the situation of rotten claws and necks, which was more common before, was also effectively controlled, and the number of losses was also within a reasonable range, entering the peak period of eating. The soft-shelled turtle eats more and grows faster, but the dung and residual bait also accumulate in the pond accordingly, the water quality will become worse and worse, and the harmful substances in the water, such as ammonia nitrogen and nitrite, will exceed the standard. At the same time, with the increase of food intake, the chances of hepatobiliary syndrome and nutritious fatty liver are also greatly increased.

At this time, the feed should be adjusted accordingly, and the total protein content in the feed formula should be appropriately reduced in the high temperature season, which can directly reduce the proportion of fish meal in the formula and increase the use of plant protein raw materials, which can effectively control the rapid growth. Large-scale death caused by many diseases. Some Chinese herbal medicine powder can be added to the feed to protect the liver and improve the health of the liver, prevent and treat hepatobiliary syndrome and nutritional fatty liver.

Microbial preparation products can be used in aquaculture water to purify water and stabilize water quality, reduce the number of disinfection in ponds, and reduce the probability of skin rot, perforation and body damage.

Epidemic disease control

When there is no wind in the outer pond in the afternoon, part of the water body can be changed to control the water surface temperature of the pond. When conditions permit, the aerator can be turned on to make the pool water communicate up and down.

When the soft-shelled turtle is cultured in the greenhouse, the water temperature is generally about 30 ℃, but the temperature inside the greenhouse will change with the change of season. At the height of summer, due to the obvious temperature difference between greenhouse culture water and greenhouse air temperature, soft-shelled turtle often breathes and is prone to soft-shelled turtle pharyngitis, so attention should be paid to regulating greenhouse air temperature. from noon to evening, open the window for ventilation and feed appropriate amount of heat-clearing and detoxification preparation to avoid pharyngitis.

In the early stage of symptomatic disease, the food intake decreased, the diseased soft-shelled turtle lay on the eating table and was in low spirits, and the mouth was panting slightly. Some sick soft-shelled turtles climb the wall, fetch water or swim backwards. The neck is red and swollen, sometimes the mouth and nose bleeds, the abdominal nail is pure white anemia, the liver is yellowish, and the tufted protuberances of the Gill tissue bleed and necrosis seriously.

If the ammonia nitrogen in the pond water is normal, the nitrite is too high, and the pH is less than 7, the oxygen increase should be reduced. Sprinkle lime 30~60ppm on the outside, take Shuanghuanglian 10 grams per kilogram and combine with respiratory antibiotics. If the pool water ammonia nitrogen is too high, nitrite is normal, pH is normal, slowly increase oxygen, you can also change the water body properly (the replacement amount is less than 1), then sprinkle with iodine preparation 3ppm, take Shuanghuanglian 10 grams per kg, combined with respiratory antibiotics.

(note: ppm is a unit of measurement, indicating parts per million)

The manuscript for this issue is provided by Zhang Jianxiong

Operator: Zhao Ying MX007