Detailed Explanation of the Key Technical Points for Artificial Breeding of Rana temporaria chensinensis

At present, more and more people are catching wild Rana temporaria chensinensis. Indiscriminate human capture and killing has caused wild Chinese Rana temporaria chensinensis resources to become increasingly scarce, even facing the danger of extinction. Rana temporaria chensinensis and Rana temporaria chensinensis oil are becoming increasingly scarce, and their prices are very expensive. Rana temporaria chensinensis products have always been in short supply on domestic and international markets. Here we mainly introduce some artificial breeding techniques for Rana temporaria chensinensis.

Site Selection for the Frog Farm

A flat piece of ground in front of or behind the house or in the yard can be chosen as the frog farm. There should be groundwater, river water or pond water nearby. Black soil or loess soil is acceptable.

Construction of the Tadpole Pond

Choose a place in the frog farm with flat terrain and easy drainage to build the tadpole pond. First, raise the ground where the tadpole pond will be built by 15--20 cm with soil so as to elevate the ground and facilitate drainage. Then pile soil around the pond to form an earth dam, with the dam height at about 30 cm. Next, pick out small stones and other debris from the pond and the dam to prevent damaging the plastic sheeting. Lay two or three layers of relatively strong plastic sheeting over the tadpole pond, and compact the four sides of the plastic sheeting with soil. Add water on top of the plastic sheeting to a depth of 20--30 cm. In this way the tadpole pond is completed. Of course, the width of the tadpole pond should preferably not exceed 2 m, as this facilitates replacing the dirty water in the pond. The size of the area depends on the number of breeding frogs introduced. Generally, 100 pairs of breeding frogs require a tadpole pond of 10—15 sq m.

Feeding During the Tadpole Stage

After tadpoles hatch, they first eat the egg membrane surrounding the eggs. They eat the egg membrane for 7—10 days, and after finishing it they begin to eat bait. Generally, mix 7 parts cornmeal and 3 parts soybean flour, add an appropriate amount of water, and after cooking until slightly dry, feed it to the tadpoles. When feeding, simply put the bait directly into the water.

Feeding of Young Frogs and Adult Frogs

After about 50 days of feeding, tadpoles become young frogs and come ashore. After becoming young frogs, they need to eat small insects, such as mosquitoes and flies, yellow mealworms, and fly maggots. As long as the temperature is suitable, the young frogs begin to move about and catch insects. Feed them daily with small yellow mealworms or maggots, scattering the insects directly on the ground around the frog farm. In actual breeding, yellow mealworms or fly maggots are generally raised to feed young frogs and adult frogs. Yellow mealworms are raised with rice husks. For fly maggots, mix 1 part pig, cow or sheep blood (any one kind) with 40—50 parts water, add a small amount of rice husks or cornmeal, and place it in outdoor vats, basins, cement pools or earth pools. In 3—5 days a large number of maggots will naturally be produced. This method is simple, quick, fast-acting and produces a large quantity.

Construction of Breeding Enclosures for Young Frogs and Adult Frogs

During the tadpole stage, the tadpoles can be raised directly under sunlight. After the tadpoles metamorphose into young frogs, the young frogs must grow in a shaded and moisture-retaining environment. Thus, breeding enclosures must be built for them. First, use bamboo poles or bamboo strips and iron rods to build an arched shed 1.8 m high, cover the arched shed with a shade net, and bury and press the bottom edges around the shade net with soil. Under the arched shed, build breeding enclosures for young frogs and adult frogs. One large breeding enclosure or several breeding enclosures can be built. After planning the size of the breeding enclosures, drive a wooden stake every 1—2 m around each breeding enclosure, with the stake standing 1 m above the ground and buried 20—30 cm underground. Then use plastic sheeting to enclose all the wooden stakes into a circular shape, bury the bottom edge of the plastic sheeting in the soil, and roll up the top edge with a 1—2 m long wooden board and nail it to the top of the wooden stakes, so that the plastic sheeting is perpendicular to the ground. Under the effect of the wooden board, the upper edge of the plastic sheeting remains parallel to the ground and forms a right angle with the wooden stakes to prevent the frogs from escaping. The tadpole pond can be built inside the breeding enclosure for young frogs and adult frogs, so that after the tadpoles become young frogs and come ashore, they can be fed directly without needing to be moved elsewhere, saving time and effort. The only thing is that when raising tadpoles, do not cover the arched shed with a shade net; wait until the tadpoles become young frogs before covering it with the shade net. Moisture retention means spraying water on the ground inside the breeding site 1—2 times a day on sunny days.

Extraction of Rana temporaria chensinensis Oil

From late October to late November each year, begin catching large female frogs. In this season, Rana temporaria chensinensis are fat, have more oil, are of good quality, and have high economic value. Rana temporaria chensinensis oil is the ovary of the female frog. The oil is obtained after drying the female Rana temporaria chensinensis. String the caught live female frogs through the nostrils at the frog's mouth with thin iron wire or cord and air-dry them for 7—10 days to make dried Rana temporaria chensinensis. Oil extraction method: after Rana temporaria chensinensis oil is taken out, it is a solid dry block and is easy to store. There are many methods for extracting Rana temporaria chensinensis oil. Generally, first place the dried Rana temporaria chensinensis in hot water at 60—70°C, soak for about 5—10 minutes, then take it out of the water and put it in a basin or other container. Cover it with wet gunny sacks or similar materials, place it in a warm room for moistening, and after about 10—15 hours the whole Rana temporaria chensinensis can be softened, with the skin and muscles becoming soft, and then the oil can be extracted. When extracting the oil, hold the softened Rana temporaria chensinensis in one hand with the ventral side facing up, press the thumb firmly against the frog's two legs, and with the other hand pinch the frog's head. Pull downward with both hands at the same time. At this point, tear open the skin near the two legs to expose the sheet-like oil. Gently pry up one end with your hand or a blade, tear off the two large pieces of oil, and at the same time take out the scattered small pieces of oil, place them on a plate and air-dry them.