CATDOLL : CATDOLL: How to keep leeches in winter

The terrain should be sheltered from the wind and facing the sun with a good environment to prolong the growth period of leeches, protect against wind and cold in winter, and enable leeches to overwinter safely. At the same time, a beautiful environment can prevent heatstroke in summer and increase the number of living plants and animals.

Due to the influence of the region, the cultivation of leeches in the north should build a sunlight wintering greenhouse under artificial conditions to break their hibernation habits, increase the cultivation time, and shorten the market cycle. In the severe cold and snowy season, snow removal and artificial heating measures should also be taken. More advanced greenhouses can be made of plastic steel without columns, but the cost is relatively high.

By building a solar greenhouse, we can systematically capture the big ones and keep the small ones, and concentrate them for the winter. During the daily management, we should pay close attention to the temperature changes inside and outside the greenhouse, as well as increase oxygen, prevent wind and cold, so as to ensure the normal growth and overwintering of leeches, and prepare enough leech seeds for the next year.

Additional information:

feed

The main types of natural bait are freshwater snails, earthworms and some insects. Large-scale breeding is supplemented by various animal blood, viscera, freshwater fish, shrimp, shellfish, snails, as well as livestock feed and crop straw.

For pond farming, a certain number of wild snails or golden apple snails can be released, generally about 0.05-0.1kg/square meter, allowing them to reproduce naturally, coexist and grow with leeches, and provide food for them.

The number of snails released should not be too large, as too many snails will compete with the main species for living space, and the host and guest will change. When feeding animal blood or mixed bait, attention should be paid to feeding at intervals and timely removal of leftover bait, especially in hot weather, to avoid polluting and deteriorating water quality and affecting the growth of leeches.

Leech farming is the use of wild leeches and other domesticated organisms. Currently, there are wild leeches such as the golden leech and the Philippine cattle leech. Through artificial breeding and reproduction, they can convert feed and other organisms into bioenergy to obtain the production of biological products such as leech bodies and medicinal materials. It is an extremely important link in the material exchange between humans and nature. Leech farming is a new thing in modern agriculture and an important way to develop traditional Chinese medicine. Preparations for leech farming 1. Intellectual investment Leech farming is an emerging business. In the past, there was a lack of experience and technology in this area. Therefore, it is necessary to understand the dynamics and supply and demand information of leech farming, master the leech farming technology, learn the primary processing methods of leeches, and understand economic accounting. Only in this way can we avoid fighting without confidence, ensure that the farming can be successful, and have sales channels, so as to obtain relatively ideal economic and social benefits. In areas with better conditions, people who plan to engage in leech farming should preferably participate in learning and training. On the basis of mastering certain theoretical knowledge, they should then visit the farm to learn on the spot. After in-depth investigation and research, they can start farming and try to avoid blindness and reduce unnecessary economic losses. The rise, consolidation and development of any farming industry must rely on science and technology. Therefore, the first preparation is to train talents and arm their minds with scientific knowledge. Only then can other problems be solved, and only then can they spend less money, do more things, and do good things to ensure the success of leech farming. 2. Investment of material and financial resources For those who already own land and water areas, the investment of farmers mainly includes the following aspects. (I) Site fence The length, size and material of the site fence, as well as the amount of investment, will be explained in detail below. (II) Seed source The seed source of leeches can be collected in the wild or purchased. When collecting in the wild, attention should be paid to the selection of varieties to prevent the mixing of varieties and the mixing of leeches with no economic value. The quality of leeches currently sold on the market varies greatly. Some are sold by piece, some are sold by weight, and the prices are also different. Farmers should carefully consider and choose when purchasing. (III) Feed For general farmers who cultivate a small number of leeches, basically they can solve the problem without spending money. However, large-scale leech farms should consider the live food for leeches to eat, or prepare animal blood, etc. (IV) Other inputs Other inputs include the purchase and construction of water, electricity, transportation, medicines, tools and mechanical equipment. All of the above inputs should be calculated and raised in advance, and done according to one's ability, and finally determine the scale of leech cultivation.

Selection of feedlots

Choosing a suitable breeding site is an important task for building a breeding farm and raising leeches. Careful consideration and careful evaluation should be made to make it economically reasonable, applicable and safe as much as possible. It is necessary to consider the living habits and requirements of leeches, as well as the terrain, water quality, soil quality, transportation, electricity, drainage, bait and other conditions to ensure that leeches have a comfortable living environment and can grow and develop healthily. 1. The living habits of leeches Leeches are aquatic, wild, temperature-changing and have special feeding habits. According to the living habits of leeches, it is required to choose a place with a certain amount of water, warm, quiet, and abundant plants and animals. Noise, especially vibration, is not conducive to the growth of leeches. Therefore, it is necessary to avoid traffic routes with frequent traffic and areas such as airports and factories with noise and vibration. 2. The choice of terrain should be leeward, sunny and with good environment. In this way, the light time can be increased in spring and autumn, the growth period of leeches can be extended, and the wind and cold can be prevented in winter, so that leeches can safely overwinter. At the same time, the beautiful environment can not only prevent heatstroke in summer, but also increase the number of living plants and animals, providing sufficient food for leeches. 3. Water quality my country has vast freshwater areas, and the quality of water in different regions is obviously different. The physical and chemical indicators that determine the quality of water are mainly temperature, salinity, oxygen content, pH value, water color and fertility. It is necessary to consider whether the water source is polluted when it flows to the site. Severely polluted waters, such as abnormal water color, increased turbidity, increased suspended matter, increased toxic substances, and foul odor, must not be used. At the same time, the water level changes in the water area within 1 year or even several years must be considered to ensure that there is water in drought and no flooding in floods. 4. Soil Different types of soil often have different pH values, types and quantities of salts, oxygen content, permeability and humus content, which will affect the growth of aquatic organisms. It is generally divided into five types: gravel soil, sandy soil, clay, loam and humus soil. If the water quality is relatively fertile, that is, it is rich in nutrients, the soil at the bottom of the pond can be gravel soil or sandy soil; if the water quality is not fertile, that is, it is not rich in nutrients, such as using groundwater or tap water, the soil at the bottom of the pond should be humus soil; if the bottom of the pond leaks, the bottom layer should also be compacted with clay. Therefore, different types of soil should be selected according to water quality conditions. The soil at the bottom of the pond should be relatively hard, with relatively fertile organic matter on it. 5. Transportation and electricity Convenient transportation can bring convenience to the transportation of products and feeds, and at the same time save time and reduce transportation expenses. In addition to daily lighting, electricity is required for processing feeds and products, and the supply should be guaranteed. 6. The water level of the drainage and irrigation breeding pond should be able to be controlled freely, and drainage and irrigation should be convenient. It is necessary to irrigate in drought and drain in flood, and both hands should be grasped. In particular, the impact of floods should be prevented to avoid unnecessary losses. 7. Bait Bait is mostly composed of aquatic plankton, snails, shellfish, shrimps, fish and other animals. At the same time, attention should be paid to the use of fresh blood of livestock and poultry in nearby slaughterhouses.

Farming method

Whether using the earth ponds and mud pits in front of and behind the house, or in rivers and lakes, there are many different ways of breeding, but in summary, there are only two ways: extensive breeding in the wild and intensive breeding. The choice of which breeding method should be based on the actual local conditions and adapted to local conditions. If the conditions are poor, local materials can be used for extensive breeding in the wild; if the conditions are good, intensive breeding can be adopted, that is, high-standard breeding ponds can be established to provide an ideal ecological environment for the growth and reproduction of leeches, and a higher unit area yield can be obtained through factory breeding. 1. Extensive breeding in the wild Extensive breeding in the wild is a breeding method that utilizes natural conditions and protects after demarcating the breeding range. Extensive breeding in the wild does not mean leaving it alone, but also requires the release of sufficient seed sources, appropriate bait, and finally fishing. Generally, there are reservoir breeding, pond breeding, swamp breeding, lake breeding, river breeding, depression breeding and rice field breeding. These methods have a large breeding area, sufficient light, abundant natural bait, small investment and high returns. However, the yield per unit area is low and difficult to manage. It is necessary to always pay attention to preventing natural enemies, preventing escape, and changes in water level fluctuations. The following briefly introduces two of the breeding methods. (I) Swamp breeding Swamps are characterized by shallow water levels, lush aquatic plants, high levels of organic matter and humus in the bottom of the swamp, and rich plankton and aquatic animals. Therefore, as long as the fence is built, leeches can be released. Regular observations should be made and bait should be supplemented appropriately. When the density is too high, timely fishing should be carried out. (II) Rice field breeding Rice fields are characterized by shallow water levels, suitable water temperatures, and shade from rice. From oxygen content to rich bait, they are suitable for the growth and reproduction of leeches. Therefore, different varieties of leeches grow in most rice fields in my country. For rice field breeding, you should choose plots with convenient drainage and irrigation, sufficient water sources, water-retaining soil, and good fertility, and enclose them with fences on all sides. In the middle of the rice field, dig one or several ponds according to the size of the plot. Generally, it is appropriate to dig a 1 square meter pond in the middle of 100 square meters. At the same time, dig a protective connecting ditch about 30 cm deep and wide between ponds and around the rice fields to connect the ponds and ditches. When drying the fields, laying fields, applying fertilizers, or spraying pesticides, leeches should be lured to the pond or protective connecting ditch with animal blood to prevent them from being killed. It is best to change fertilization to deep application of ball fertilizers, and it is best to change pesticide spraying to low-toxic or non-toxic pesticides. 2. Intensive intensive breeding Intensive intensive breeding is a scientific breeding and management method that uses artificial pond construction and feeding of bait. Generally, there are fish pond breeding, field breeding, indoor breeding, courtyard breeding, and factory-based constant temperature breeding. These breeding methods have a large stocking density, relatively high capital investment, and require sophisticated breeding technology. However, the output per unit area is high and the economic benefits are good. (I) Physical properties of intensive breeding 1. 1. Strong light transmittance and small fluctuation of water layer: Because the water is shallow, sunlight can penetrate to the bottom of the pond, which is conducive to the healthy growth and development of plankton, submerged plants and benthic plants. At the same time, because the water is shallow, the upper and lower layers of the water are basically uniform, and only small fluctuations occur under windy and temperature changes. It provides a good living environment for leeches. 2. Uncertain water color and seasonal changes in water temperature: The color of water often varies depending on the soil quality, water depth, type of fertilizer and the growth and reproduction of plankton in the water. This is because the water body is green when there are many phytoplankton, yellow when there are many zooplankton, brown or soy sauce color when there are many humus, turquoise when there are a lot of blue algae, yellow-green when there are a lot of fish algae, brown when ciliates reproduce vigorously, and red when there are a lot of water fleas. 1. The water temperature is the lowest in winter, gradually rises in spring, the highest in summer, and gradually decreases in autumn. The water temperature is relatively high from May to September in a year, which is a suitable period for leeches to grow and reproduce under natural conditions. l The average temperature at noon is generally higher than the air temperature, and the average temperature difference is lower than the air temperature. In this way, the water temperature is relatively stable compared to the air temperature. The water temperature is often lower than the air temperature during the day, while it is higher than the air temperature at night. 3. If the water body deteriorates, the water will emit a foul smell: If the water body has a special rotten smell or odor, it means that the water body is polluted, indicating that the organic matter at the bottom of the pond, such as leftover bait, animal and plant remains, and feces, will decay and generate toxic gases such as ammonia and hydrogen sulfide. At this time, the water should be changed or the pond should be emptied and cleaned in time to prevent the death of a large number of leeches. (II) Chemical properties of intensive breeding 1. Acidity (pH value). Acidity refers to the pH value of the water in the pond. It is mainly the change in the ratio between free carbon dioxide and carbonates in the water. Its range of change is generally between 6.5 and 9.5. The pH value changes periodically between day and night: at dawn, the carbon dioxide content is high, and the pH value of the water decreases (becomes acidic); during the day, the carbon dioxide content decreases, and the pH value of the water increases (becomes alkaline). Practice has shown that neutral or weakly alkaline water is conducive to the growth and development of leeches. 2. Dissolved gas content. Gases include oxygen, carbon dioxide, nitrogen, ammonia, hydrogen sulfide and methane (marsh gas). Generally, the oxygen and carbon dioxide content in the water is more important. When the oxygen content in the water is greater than 0.7 mg/L, the leeches will move normally; when the dissolved oxygen in the water is less than 0.7 mg/L, the leeches will crawl out of the water and go to the soil or grass on the shore to breathe oxygen in the air. The content of these two gases in the pond is closely related to the diurnal changes in water temperature. The time with the highest oxygen content is in the afternoon, because the green plants in the water have strong photosynthesis at this time, consuming carbon dioxide and producing a large amount of oxygen. The oxygen content in the water is lowest at dawn, because the photosynthesis of plants basically stops at night, while animals do not stop consuming oxygen and exhaling carbon dioxide. 3. Dissolved inorganic salts. Inorganic salts include nitrates, phosphates, carbonates and silicates. The dissolved amount of these salts has a direct impact on the number of plankton and other plants and animals, and on the growth and reproduction of leeches. (III) Intensive biological composition In different regions and seasons, the biological composition of ponds is obviously different. But generally it is composed of the following major categories of organisms. 1. Plankton: Plankton is generally tiny plants and animals that are invisible to the naked eye. Their mobility is limited, and most of them move passively by the flow of water. They are the main part of the pond's biological composition and have an important impact on the growth and development of leeches. Phytoplankton mainly includes lower phytoplankton, such as blue algae (Microcystis, Anabaena, etc.) that reproduce in large quantities in summer, green algae (Drum Algae, Coccosphere Algae, Volvox), and diatoms that grow vigorously in spring and autumn. Zooplankton mainly includes the most primitive and lowest class of animals in the animal kingdom. Most of them are single-celled organisms, such as Paramecium, trumpet worms, and caudal spiny worms. 2. Aquatic plants: Aquatic plants mainly include the following types. (1) Floating plants such as duckweed and duckweed, which float completely on the water surface or in the water. (2) Floating leaf plants whose leaves float on the water surface and whose roots grow in the bottom soil of the pond, such as water chestnuts and water spinach. (3) Erect leaf plants whose roots are rooted in the soil and whose stems and leaves stand upright above the water surface, such as reeds and water chestnuts. 3. Benthic animals: Benthic animals include clams and snails among mollusks, shrimps and crabs among crustaceans, non-planktonic cladocerans and copepods, as well as water maggot exuviae, chironomid larvae, clam python larvae, etc. 4. Other animals mainly include fish, leeches, water snakes, turtles, water rats, etc. 5. Fungi and bacteria In seriously polluted ponds, various fungi and bacteria that endanger the life of leeches multiply in large numbers, causing a great impact on the growth of leeches. Biological characteristics of leeches: 1. Classification of leeches Leeches are relatively ancient lower animals on the earth. According to the analysis of amber fossils embedded with leech remains picked up from the Baltic Sea coast, leeches have a history of at least 40 million to 50 million years. Leeches belong to the phylum Annelida, class Hirudinae, order Gnathodidae, family Hirudinae. The class Hirudinae includes 4 orders, namely, the order Acanthodidae, the order Rhinoceros, the order Gnathodidae, and the order Pharyngodendidae. The following mainly introduces the order Gnathobdellidae. Animals of the order Gnathobdellidae do not have a retractable proboscis, a fixed pharynx, and three jaws in the mouth. There is no real vascular system in the body, which is replaced by a hemocoelom system. The hemocoelom fluid is red and has grape-like tissue. The reproductive system is relatively complex, usually with a mating organ, and the egg cocoon contains a protein-nourished embryo. The complete body segment is basically developed from 5 rings. Aquatic or terrestrial. For example, the Japanese leech (Hirudo nipponica) and the Japanese leech (Hirudo niphidae), which are used in surgical procedures such as bloodletting, clearing blood stasis, and replanting severed limbs; the cattle leech, which was widely used for bloodletting in ancient India to avoid the need for surgical scalpels: the rod-shaped cattle leech (Poecilobdella javanica), the far-hole cattle leech (P. similis), and the Philippine cattle leech (P. manil-lensis); the mountain leech, which lives in warm and humid mountainous areas, waits for passing hosts in grass or bamboo forests and sucks the blood of vertebrates: the Japanese mountain leech (Haemadi Psa japonica), the Tianmu mountain leech (H. tianmushana), and the Yanyuan mountain leech (H. yanyuanensis); the golden thread leech (Whitmania) is very common in ponds and rice fields in my country: the wide-bodied golden thread leech (W. pira ), smooth golden leech, pointed golden leech. 2. Ecological habits Most leeches live in fresh water, a few live in sea water, and some species of leeches can live on land. Leeches can often be found in waters rich in organic matter, such as ponds, lakes, rivers and streams. Leeches prefer neutral or slightly alkaline waters and are not adapted to acidic waters. Due to changes in the ecological environment, leeches can dive into the bottom of the water and live in burrows in dry rivers, and can even survive when they lose 40% of their body weight. Some leeches can live amphibiously in water and on land. There are also very few leeches that can live in humid jungles on land, such as mountain leeches. A considerable number of leeches live semi-parasitic lives, and a few leeches live carnivorous lives. Leeches are flat on the back and abdomen, with a thinner front end, and their body shape is leaf-shaped. The body can change with the degree of expansion and contraction or the amount of food taken. The body length is between 1 and 30 cm, and most leeches are between 3 and 6 cm long. The body surface is dark brown, blue-green or even brown-red, with stripes or spots on the surface. The body is segmented, and the segments at the front and back end have evolved into suckers, which have the functions of adsorption and movement. The front sucker is smaller and surrounds the mouth, while the rear sucker is larger and cup-shaped. The number of body segments is fixed, but is often covered by rings on the body surface, such as the medical leech. The medical leech is about 10 cm long and can be divided into more than 100 body rings. The growth of the body is lengthened by the extension of the body rings. The body segments at the front and back ends of the body are transformed into suckers, the front sucker is small and the rear sucker is larger and has rings.

Winter Leech Management

1. Winter management: Ensure the safe wintering of leeches. After winter, the temperature drops below 10℃, leeches stop feeding, burrow into the soil or under leaves to hibernate. Leeches released in early spring are generally grown into adults and can be processed and sold. When fishing, drain the water first, then use a net to pick up, select large and strong individuals for seed, 15 to 20 kilograms of seeds per mu should be kept, and concentrated in the breeding pool for wintering. It is possible to drain the water for wintering. After draining, straw or wooden poles can be added to the surface of the pool to prevent freezing and keep the soil moist. It is also possible to winter with ice, and the pool water should be appropriately deepened to prevent complete freezing.

2. Wintering in greenhouses is affected by the region. Leech breeding in the north should establish a solar wintering greenhouse under artificial conditions to break its hibernation habits, increase the breeding time, and shorten the market cycle. Solar greenhouses are generally bamboo and wood plastic thatch structures. The northern walls are cast earth or brick-concrete, 0.8-1.5m thick, east-west, 30-50m long, 10-15m north-south span, and 5-7 rows of main columns. Cover with drip-free plastic film and rollable straw thatch, leaving doors, passages and vents. In the severe cold and snowy season, snow removal and artificial heating measures should also be taken. More advanced greenhouses can use plastic steel without columns, but the cost is relatively high.

3. By building a solar greenhouse, we can systematically capture the big ones and keep the small ones, and concentrate them for the winter. During the daily management, we should pay close attention to the temperature changes inside and outside the greenhouse, as well as increase oxygen, prevent wind and cold, so as to ensure the normal growth and overwintering of leeches, and prepare enough leech seeds for the next year.

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1. Water quality management. Water is one of the most important factors for leeches. The reason why wild water is becoming less and less is that the quality of water has deteriorated, which makes it impossible for leeches to survive. The water for raising leeches should be natural and pollution-free. Some water with high fertilizer or pesticide content will have a serious impact on leeches, so farmers should be cautious when choosing water sources. Secondly, in order to ensure the quality of the water source in the breeding pond, it is best to keep the flow of running water for a long time.

2. Breeding density. Don't think that leeches are small and you can raise a lot of them per acre. Generally speaking, the number of leeches per acre is about 2200-2500, and the seedlings are generally about 40-50 kilograms. Because there is no way to ensure that leeches can be evenly distributed throughout the breeding site, a slightly smaller number can maintain the growth rate and quality of leeches. Therefore, it is best to divide the breeding site to maintain the uniform distribution of leeches to the greatest extent.

3. Feeding. Common food for leeches is snails, river clams and some animal blood clots. In the early stage, place a certain number of snails and river clams evenly in the breeding site, and then feed them with some blood clots to speed up their growth. Generally, they can be fed once in the morning and evening. The feeding time is usually controlled at about 1-2 hours. Feed a small amount each time to allow the leeches to eat as much as possible and reduce feed loss.

4. Temperature control. Leeches are very afraid of high temperatures, so the breeding site must have temperature control methods, especially in summer. In summer, it is best to build some shade nets or put some floating aquatic plants in the water to reduce the chance of direct sunlight contact with leeches. If the temperature is too high, it is best to increase the depth of the pool appropriately to keep the temperature at the bottom of the water more suitable for growth.

This article is from: China Agricultural Press "China Biotechnology Development Report"