Exploration on Artificial Breeding Technology of Rana chensinensis

Chinese forest frog is a special and precious wild animal in China, and it is a valuable traditional Chinese medicine, nourishing food and delicacy. Chinese forest frog is also a forest guardian, which plays a certain role in promoting forestry production and income and protecting forest ecological environment. Northeast China is rich in forest resources, suitable environment, good vegetation and rich water resources, so semi-artificial forest frogs are gradually developed in various parts of the mountain area. However, in the process of semi-artificial culture of forest frog, the problem of low return rate has been perplexing forest frog farmers. This paper introduces the semi-artificial culture technology of forest frog, including the selection and construction of forest frog breeding farm, hatching method, feeding and management of tadpoles, recapture of forest frog, management of overwintering period, etc., and expounds various measures to improve the return rate of forest frog in each growth stage.

Chinese forest frog (Rana chensinensis) is an amphibian, Anura, frog family, frog genus, is a precious wild animal specializing in China, with high nutritional value, its fallopian tube (frog oil) is a precious medicine of traditional Chinese medicine, with the functions of tonifying deficiency and reducing fever, tonifying liver and kidney, nourishing lung yin, mainly treating diseases such as fine fatigue and neurasthenia, its delicate meat and delicious taste is a delicacy at the banquet. Frog eggs, head, skin and other parts are good raw materials for making beauty and health products. The semi-artificial culture of Chinese forest frog has opened up a new way for people in our northeast forest region to get rich.

1 selection of breeding grounds

1.1 the topography is relatively flat and convenient for irrigation and drainage, and the soil condition is that the clay and loam with low water permeability and strong water retention are better, which is beneficial to water storage and water retention in the pond, which is the premise that the water temperature can be stable. it is also a necessary condition for tadpoles to metamorphosis in advance. The breeding farm had better be centralized and easy to manage.

1.2 the source of water requires sufficient water, and there is no pollution to ensure the water consumption of the breeding grounds. In addition, the choice of breeding farm had better be near the stocking farm, so that the combination of reproduction and stocking, which will save a lot of manpower and material resources.

(2) Construction of breeding grounds

The spawning incubator shall build a spawning incubator in the area where the terrain is flat and close to the water source. The pool is generally 40cm deep, the bottom of the pool is flat, and sundries such as stones and gravel are removed, which is helpful to improve the water temperature. There is a water inlet on the pool and a water outlet is arranged diagonally, so as to speed up the renewal of pool water, and the outlet is blocked by sand net to prevent tadpoles from swimming out of the water. For the incubator with high water permeability, the bottom of the incubator can be covered with plastic sheet. in order to reduce the cost, a small piece of waste plastic film can be used to cover the bottom of the incubator, then compacted with soil and soaked in water. The construction of the incubation pool is best completed in summer and autumn and does not affect the hatching in spring.

2.2 before spawning, some branches are randomly placed in the spawning incubator to stabilize the egg mass and slow down the flow speed as much as possible during this period to maintain the water temperature in the pond. You can also fill the pool with water in advance and close the inlet and outlet. After laying eggs, in case of frost weather, frog eggs can be covered with grass curtains and other things to protect frog eggs. When drought and lack of rain, turn the egg mass regularly, or you can press the egg mass into the water to keep the egg mass moist. For the egg mass that sank to the bottom, pick it up with a net, rinse off the sediment with clean water, and then use a wooden stick under the egg mass to lift the egg mass and turn it 1-2 times a day.

(3) feeding of tadpoles

To raise forest frogs well, tadpoles must be raised first. In order to improve the survival rate of tadpoles, the following points must be done: adequate ① feed and balanced nutrition. The density of ② is suitable and the age class is the same. ③ change the water reasonably and keep the water temperature. ④ to prevent diseases, insects and natural enemies. Only by doing the above can we lay the foundation for raising forest frogs.

In practical management, temporary tents can be set up and stoves can be set up to prepare feed. Tadpoles that have just hatched membranes will not feed, but will feed on egg membranes. A week later, they will be fed with boiled bean cakes, corn and other refined fodder. Pay attention to the feed must be cooled before feeding. Must be fed evenly, to avoid some tadpoles can not get food, tadpoles like to eat is generally 8 ∶ 00:00 every day, 16 ∶ 00:00, so it is best at this time to feed. If most of the tadpoles quickly concentrate on the feed, it is proved that the tadpoles are in a state of hunger, indicating that the amount of feed is insufficient, so it is necessary to increase the amount of feed properly.

Tadpoles stop feeding on concentrate feed after the forelimbs grow and before the tail disappears, mainly eating live animal food. During this period, try to avoid walking around the edge of the pool, so as not to disturb the tadpoles and avoid stepping on the small frogs that have landed.

The water temperature in the pool should be kept between 10-24 ℃. If the water temperature is too low, the tadpole will grow slowly, and if the water temperature is too high, the tadpole will die. The time of changing water should be after 00:00 of 16 ∶ every day, because there is little difference in water temperature between Hanoi and the pool at this time, which can keep the water temperature in the pool relatively stable. Through the regulation of water exchange measures, we can not only maintain the water temperature in the pond, but also ensure that the pond water has sufficient oxygen and nutrients. Shallow irrigation in sunny days and deep irrigation in cloudy days, it is necessary to timely grasp the time of changing water, and adjust the depth of the pond at any time according to the weather and the environment of the pond to adapt to the growth of tadpoles. With the gradual growth of tadpoles and the rise of temperature, it is necessary to speed up the replacement of pool water in order to increase the content of oxygen and nutrients in pool water and ensure the normal growth of tadpoles.