Breeding techniques for increasing the yield of bullfrog

The breeding of commercial frogs refers to the process of turning abnormal young frogs into commercial frogs, which is not only the last link of the whole bullfrog breeding, but also the most critical production process to determine the success or failure of production. At present, commercial frog culture can be divided into two ways: intensive culture and extensive culture. Extensive breeding is the construction of a relatively wide area surrounded by anti-escape facilities. Bullfrogs' young frogs are allowed to eat natural bait and grow naturally in this natural environment, and are caught and sold after meeting the commodity specifications. And intensive culture is to dig smaller artificial ponds, using artificial bait, high-density full artificial culture, the yield and survival rate of this culture method is very high, is now more commonly used culture method, the following focus. Introduce this method of farming.

I. Construction of breeding grounds

1. Frog ponds: the breeding ponds of commercial frogs are generally excavated. In order to save farmland and cost, ponds, lotus root ponds and small ponds can be slightly reformed. The location should be in a place with flat terrain and adequate water sources, with an area of 100 square meters to 300 square meters, a pond depth of 0.8 meters to 1 meters, a water storage capacity of 30 centimeters to 40 centimeters, and a net encirclement around the soil ponds to prevent frogs from escaping: high-yield intensive farming can also build special cement ponds with an area of 15 to 30 square meters. The depth of the pool is 1 meter, the water storage is determined by the size of the frog body, and it is made of concrete, and the bottom of the pool is flattened with cement, and the slope of the bottom of the pool should be large, so as to ensure that one end of the water is deep when raising frogs, which is the main habitat of frogs, and the water at one end is relatively shallow, often exposing the bottom of the pool, so that the frogs can come here to eat and rest; the bottom of the pool should also be inclined to the outlet to ensure that the water can be drained. In order to prevent the escape of frogs, the top of the surrounding pool wall should be poured or built into 10 cm eaves. The output of cement pool is high. At present, 15 kilograms of frogs can be produced per square meter in China, which is suitable for intensive and high-yield frog breeding.

2. The small environment of the frog pond: in order to ensure the good growth and development of the bovine moth, a good ecological environment should be created for the bullfrog. Some aquatic plants such as lotus root, mushroom, calamus and so on can be planted in the frog pond, which is suitable for the bullfrog. Flowers, grasses and shrubs should be planted on the land and slope of the frog pond, so as to facilitate bullfrogs to come here to perch and attract insects as bait for frogs. In order to prevent the impact of summer high temperature on bullfrogs, we should build a half-pool shade shed on the south bank of the frog pond in spring, plant some climbing vines such as pumpkin, towel gourd and grapes, climb up the shade, and let bullfrogs come here to have a summer rest in the hot season. Through this arrangement, the ecological environment of the whole frog pond is more suitable for the life and growth of bullfrogs.

3. Cleaning and disinfection of frog ponds: the newly built cement ponds should be soaked in water for 15 days before use, and can not be released until the young frogs are released and replaced with new water. Soil ponds such as newly opened ponds should also be irrigated and soaked for 5 days before use to remove excessive heavy metal salts. Before stocking, cement ponds should also use 1 mg of bleach per liter or 20 mg of quicklime solution per liter to rinse the bottom and walls of the pool; soil ponds should be sprinkled with 90 ~ 110 grams of quicklime per square meter or 7.5 ~ 15 grams of bleaching pulverized water.

II. Stocking, bait, feeding and management of young frogs

The stocking amount of young frogs should be determined by many factors, such as frog size, feed status, feeding management level and so on. Soil ponds are generally stocked with young frogs that are just abnormal (4g ~ 5g): 100 ~ 120 per square meter, and the stocking capacity of cement ponds can be increased by 1 / 2 times.

1. Artificial bait for frogs: in high-density intensive culture, natural bait alone can no longer meet the needs, so artificial bait must be fed. At present, the main artificial baits used for raising frogs are insects induced by light, artificial cultivation of fresh bait such as earthworms, fly maggots and artificial production of mixed pellet bait. Artificial pellet feed can be prepared according to frog at different developmental stages and sizes, and the feed coefficient and cost are low. In addition, some drugs can be added properly during preparation, which can also play a role in disease prevention and treatment. The experiment shows that as long as the young frogs are just metamorphosed, that is, live bait such as earthworms and small fish and shrimp are fed together with static bait such as pellet bait, so that the static bait can be activated under the drive of live bait. young frogs can eat static bait, and the effect is very good, which solves the key problem for intensive bullfrog culture.

Under the condition of artificial feeding, the food intake of bullfrog varies with temperature, frog size and food type, and the feeding amount is roughly between 5% and 15% of the total body weight of the frog.

2. Feeding and management: under the condition of artificial intensive culture, bullfrogs eat a lot of food and feces, which is easy to pollute and worsen the water quality, which will lead to diseases, which is more prominent in cement ponds. Therefore, the cement pool should be washed frequently, and the pool water should be changed regularly and sterilized with 20 mg quicklime per liter or 1 mg bleach per liter every 15 days from mid-April to mid-late October. When the water temperature rises above 32 ℃, the bullfrog will lose its appetite and die when it continues to rise to 35 ℃. At this time, in addition to shading by climbing vines, new water from other rivers with lower temperature should be injected if necessary, and all measures should be taken to control the water temperature in the pond below 32 ℃ to ensure the normal life and growth of frogs.

Due to the high density of frogs, young frogs will have different sizes after a stage of feeding because of the uneven feeding of bait and the difference of physical strength between individuals. Bullfrogs have the bad habit of eating big and small, so they should be raised in ponds according to their size in time to improve the survival rate of frogs. When the specification reaches 25 g ~ 50 g, it will be adjusted to 60 ~ 80 per square meter; when the specification reaches 100 g, it will be adjusted to 30 ~ 40 per square meter; when the specification reaches 150 g, it will be adjusted to 20 ~ 30 per square meter.

Bullfrogs are good at climbing and jumping, so they should often check anti-escape facilities, repair damaged ones in time, and always observe whether there are snakes, rats and other enemy hazards. Once found, they should be caught and killed in time to ensure the safe growth of frogs.