The squid can spawn naturally in running water or in still water, but artificial breeding can achieve better spawning and hatching effects. First, broodstock breeding (a) sexual maturity and sex cycle. Females in the Yangtze River Valley are generally 2 years old, and mature males and females older than 1 year. Generally from March to May is the period of gonad maturation and spawning. After the oviposition period, the ovary of stage VI is degraded to the second stage in July, and gradually develops until the fourth stage in November. During this period, the ovary is overwintering. In the second year from March to April, it encounters suitable environmental conditions. The ovary is rapidly maturing and quickly progresses from stage IV to stage V. Sexually mature males degenerate into the third phase of the testes after their breeding, enter the fourth phase from August to September, and enter the fifth phase in December, and overwintering this period. The spawning season varies from north to south. The spawning season in the south is from February to March; the Yangtze River basin is from March to April; the Yellow River Basin is from April to May; and the Northeast from May to June. The spawning period generally lasts about 2 months. (B) Identification of male and female. 1, females. Body shape: back height, body width, head small; chest and pelvic fins: smooth, no or little starchasing; abdomen: mature expansion, loose, full appearance; reproductive hole: larger, slightly red, swollen, protruding. 2, strong. Body shape: body narrow, long head; chest and pelvic fins: reproductive season chest, pelvic fins and lid cover Starchaser; abdomen: narrow and slightly hard, mature seminal abdomen after light Asia; genital hole: smaller, slightly concave inward . (C) the choice of broodstock and feeding. Female squid should be selected over 2 years of age, weight 1 kg or more, male squid slightly smaller body weight of about 0.5 kg. The selected broodstock should be tall, thick, healthy, strong, well-shaped, and strong without injury. The source is raised in ponds. The broodstock area is generally 1 to 3 mu and the water depth is about 1.5 meters. The stocking density of broodstock is generally 100-150 kg/mu, and it is also possible to feed a small number of cockroaches and squid in order to control the over-breeding of plankton. Before wintering, male and female relatives must be reared separately to avoid spawning when the temperature rises abruptly. In order to avoid sporadic spawning when the temperature rises abruptly, it is possible to divide males and females separately or raise a pool. The squid is omnivorous and has a large amount of food. It should give enough food during the breeding period. Fertilizer can also be fertilized properly and the natural food is sufficient. Note that 10 to 15 days before spawning, fortified with high-quality feed to facilitate the development of gonads. Second, the natural spawning fertilization (a) the choice of spawning, hatching pool. The spawning pool is preferably 0.5 to 1 mu and the water depth is 1 to 1.5 meters. Should choose to avoid the wind, sunny, less silt, injection and drainage convenient, quiet environment of the pond. 7 to 10 days before the release of fish, clear ponds such as quicklime are used. When the water is injected, it is tightly filtered, the water is fresh, and the oxygen content is high. Normally, the fry rearing pool doubles as the hatching pond, where the fry is hatched and then reared on the spot. It requires a pond area of ​​1 to 2 mu, a water depth of 0.7 to 1 meter, and a clear pond before fish release. (b) The production and setting of fish nests. Salmon is a viscous egg that requires attachment so that the fertilized egg adheres to it. Artificially placed eggs are often called fish nests. The natural materials that make up the fish nests can be applied as long as the texture is soft, and the slender whiskers are more easily dispersed in the water. Commonly used in the production of aquatic plants (grass, goldfish, etc.), willow root, palm, ferns, etc., and now also developed a man-made fiber production of fish nests, more durable. After the fish nest material has been sterilized, it is bundled into bundles of appropriate size and is not sparsely dense, and then it is tied to thin bamboo poles or tree strips. Common settings are suspended and flat columns. Generally, the fish nest is arranged in a shallow place about 1 m from the shore, and the bamboo raft is submerged into the water by 10-15 cm so that the fish nest is in a floating state. When managing, pay attention to the timely exchange of fish nests according to the situation of eggs. (c) Matching group spawning. The squid can lay eggs naturally in common lakes and ponds. When the spring water temperature rises to about 18°C, it begins to lay eggs. Male and female bred broodstock need to be pooled with the group, should be sunny and warm in the wind, or rain after the first sunny weather, select mature male and female broodstock, 1:1 ratio, into the spawning pool spawning. From midnight to the morning of the next day from 6 to 8 o'clock, the most abundant spawning will be stopped at noon. Third, artificial insemination When the natural spawning due to the weather, spawning is not much, when the drag is too long, through artificial oxytocin and artificial insemination, can promote egg maturation, spawning, emergence and neat. The dose requirement for oxytocin is not very strict for salmon, and pituitary, chorionic hormone and the like are all effective for the production of salmon. The injection dose of female fish is 4-10 mg/kg in pituitary gland or 1500-2000 IU/kg in chorionic hormone or 35-100 μg/kg in hormone releasing analogue. It can also be used as a mixture of two hormones. The effect is better. The dose of male fish is half that of female fish, and one injection method is used. Injections are prepared and injected in the same way as the four homes. The injection is generally performed at 4 to 5 pm. After the injection, the broodstock is placed in the spawning pool, flushed for 1 to 2 hours, and placed in a fish nest. Usually, the eggs can be laid on the night or the following morning. Artificial insemination can also be performed after oxytocin. The eggs of squid are not exposed to water and are not sticky. Dry insemination is generally used. First dry the broodstock's body surface, squeeze the eggs into the basin, then squeeze the sperm on the egg, mix gently with feathers, make full contact with sperm and eggs, add water to fertilize, and evenly spread the fertilized eggs in shallow water. The hatching of the fish nest. IV. Incubation (1) Pond hatching. At present, the fry hatchery cultivation pool is used for hatching in order to reduce the trouble and loss of fry. The fish nests with fish eggs are placed in the pool and fixed 10 centimeters below the water surface. About 25-30 million eggs can be placed per acre of water. If the survival rate is 60%, the density of the fry per acre is 15-18. Million. When the fry is hatched, it is not possible to remove the fish nest immediately. At this time, the fry is attached to the fish nest most of the time. The yolk sac provides nutrients. When the fry can actively swim and feed, the fish nest can be removed. (b) Drenching water hatching. Place the nest of nested eggs on the shelf or hang it on a shelf and keep the nest wet with water. This method can artificially control the indoor temperature and humidity during hatching, observe the embryonic development, have the same hatching speed, reduce the damage of aquatic mold, hatching is not affected by meteorological changes and so on. When the embryo develops to the eye-opening stage, the fish nest should be immediately hatched in the hatchery. Note that the temperature difference between the indoor and the pool does not exceed 5°C. (c) Incubation of de-bonded flowing water. The viscous eggs produced by squid are removed after the artificial insemination, and then incubated in the incubator of the fish. Using this method can avoid the invasion of predators, fresh water, rich in dissolved oxygen, suitable for large-scale production, without making fish nests, saving materials and labor. 1, mud debonding method. Synthesize slime water with yellow mud, first add 5 to 1 kg of yellow mud to 5 kg of water, and filter through 40 mesh cloth. Slowly pour the fertilized eggs into the muddy water and constantly turn the mud water for 2 to 3 minutes. Transfer the debonded eggs to the cage to wash the mud, and then put the eggs into the incubator to incubate. 2, talcum powder debonding method. 100 grams of talcum powder, namely magnesium silicate, is added with 20-25 grams of salt in 10 liters of water, and stirred to form a mixed suspension, which can be used to de-glue eggs of 1 to 1.5 kilograms. During the operation, the egg was slowly immersed in the suspension and gently stirred with feathers. After half an hour, the fertilized eggs were dispersed particles. After rinsing, the fertilized eggs were placed in an incubator for running water.
Joint Replacements
Joint replacement is a medical treatment in which an artificial joint is used to replace a painful joint that has lost function.Our joint replacements are divided into Hip Artificial Prosthesis and Total Knee Artificial Prosthesis System.
The artificial femoral stems are also available in a plain type (which requires cement) and a coral type without cement. Indications for joint replacement include osteonecrosis, irreducible comminted fractures and dislocations, osteoarthropathy with pain and mobility disorders, rheumatoid arthritis with rigidity or difficulty in mobility, and bone tumors. Complications of replacement include loosening of the prosthesis, wear or fracture, deep infection, foreign body reaction, and soft tissue calcification that impedes movement.
hip Replacements,Hip Implants,Hip Artificial Prosthesis,Artificial Prosthesis
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