Silkworms reproduce with eggs.Silkworm eggs look like fine grainssesame, about 1mm wide and 0.5mm thick.A female moth can produce about 450~500 silkworm eggs, weighing about 1 gram.When the silkworm eggs are just laid, they are light yellow or yellow. After 1-2 days, they become red bean color, and after 3-4 days, they become grayish green or purple again. They no longer change, and are called fixed color.The outer layer of silkworm eggs is hardEggshellThe yolk and serosa are inside. The embryo in the fertilized egg continuously absorbs nutrients during development, and gradually develops intoAnt silkworm, it crawls out of the egg shell, which becomes white or light yellow after being empty.
In addition, the main substances that generally constitute silkworm eggs are water 65%, protein 20%, lipid 10%, carbohydrate 4%, inorganic salts, etc. Protein is the basic unit molecule of amino acid, which is highly overlapped, accounting for the main part of dry weight, and is an important material for the construction of egg shells or egg cells. In addition, many protein molecules have functions and functions like enzymes,It is a hard protein such as glycine or histidine, accounting for 22-29% of the dried egg shell weight
Breeding method
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1. Selection and storage of tussah cocoons
Choose the tussah cocoons without diseased pupae and tender pupae, with the female cocoon rate of more than 80% and the 1000 grain weight of more than 11kg;Store the selected tussah cocoons in a cocoon holding warehouse at 0 ℃ ± 2 ℃ and 50%~70% RH. The cocoons are stored in layers in the warehouse with cocoon beds, or stored in cocoon cages and baskets, and checked regularly. The cocoons are even and free from heat, moisture and mildew.
2. Cocoon heating
According to the bee breeding plan, arrange the cocoon warming date. Before cocoon warming, thread the cocoons into strings, that is, thread the fine thread through the floating hairs at the tail of the cocoon. The insect peduncle faces outward and downward, thread into cocoon strings, and hang them in the cocoon warming room. The cocoon warming temperature rises from low to high, starting at 10~12 ℃, and gradually increasing by 1~2 ℃ every day. When it rises to 20~22 ℃, it remains stable, and the maximum temperature does not exceed 25 ℃, RH60%~75%.
3. Storage of moths
The male moth eclipses earlier than the female moth. In order to prevent mating between male and female moths and stimulate female moths to spawn by themselves, the male moth shall be collected first, and then the eclipsed female tussah moth shall be stored at 0~2 ℃ for 24~48 hours.
4. Egg collection and washing by laparotomy
The head of the female moth is lifted off first, and then its abdomen is put into the dissecting machine to dissect and take eggs. After the eggs are washed, the insect fragments and capsule impurities mixed between the eggs are removed, and then the immature eggs are put into the green egg cleaner to remove the immature eggs, and then the crushed shells of the crushed immature eggs are washed with water to reduce the green egg rate to less than 3%.
5. Disinfection and drying of eggs
Send the cleaned eggs into the egg disinfection room, and use 0.1%BromogeramineSoak the solution for 8-12 minutes, take it out, dry it, and dry it in the shade in the workshop.[1]
Silkworm egg management
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Necessity and requirements of egg surface disinfection
The surface of newly laid tussah eggs is not only adhered with scale hairs, moth urine, dust and other dirt, but also has a large number of pathogenic microorganisms. Ant silkworms will be eaten together with the egg shells when they hatch, causing the silkworm to be infected with diseases. The surface of eggs must be disinfected before the larvae hatch.
1 Pay attention to disinfection work. All kinds of pathogens generally exist in the environment, especially in the environment just after seed production.We should not only attach importance to the disinfection of egg surface, but also thoroughly disinfect and sterilize the houses and tools for egg preservation.The sterilized house shall be kept sterile to prevent re infection after disinfection.
2 Strictly control the disinfection temperature Several drugs commonly used for egg surface disinfection must be under certain temperature conditions in order to exert the maximum efficacy of killing pathogens and complete disinfection.If formaldehyde is used for disinfection, the disinfectant must be kept at 23~25 ℃;Disinfect with hydrochloric acid or sulfuric acid, and keep the temperature of disinfectant at 20 ℃;The temperature of bleaching powder disinfectant should be controlled at about 18 ℃.The temperature in early spring is low, so heating equipment shall be provided during disinfection to maintain the specified liquid temperature.
3. The concentration of disinfectant solution should be accurate. The concentration of disinfectant solution on egg surface is too high, which affects the physiology of embryos;If it is too low, the disinfection effect will be affected.Therefore, the concentration of disinfectant solution must be accurate.Commercially available drugs shall be prepared according to the standard concentration after the content of their ingredients is determined.During the disinfection process, the concentration of the solution will gradually decrease due to repeated egg dipping disinfection.
4 The time standard must adhere to the length standard.
Standard and method of egg surface disinfection
The disease prevention agents should be selected according to different control objects.The mixed solution of hydrochloric acid and formaldehyde can also be sterilized with 3% formaldehyde for 30min, and then with 10% hydrochloric acid for 10min.Formaldehyde and bleaching powder are mainly used to prevent sepsis and microparticle disease;Hydrochloric acid and sulfuric acid are mainly used to prevent and treat malacia.The mixture of formaldehyde and hydrochloric acid has good disinfection effect on pyosis, microparticle disease and malacia.
Egg surface disinfection method 1. 3~5 days after laying eggs or 1~2 days before leaving the silkworm, put the eggs into a leaky container such as a plastic yarn bag and immerse them in clean water to bathe the seeds. The water temperature is the same as the natural temperature. Gently rub and wash off the attachment on the egg surface.0.5%~1%sodium hydroxideAfter washing eggs with solution for 55s, the adhesive substance on the egg surface is washed away and has disinfection effect, and then it is washed clean with clean water and emptied of water.The concentration and time of sodium hydroxide bath seed should be strictly controlled because it can dissolve the egg shell.It can also be directly sterilized without bath seeds.2. Egg surface disinfection Immerse the silkworm eggs that have undergone seed bath and leaked water into the disinfectant solution of standard temperature and concentration for disinfection, and then wash the silkworm eggs with clean water close to the temperature of the disinfectant solution until there is no medicine taste.Finally, the silkworm eggs are naturally dried in a non-toxic environment.
Management of egg surface after disinfection
1. The thickness of silkworm eggs should be controlled within 1~1.5kg/m2.Turn the silkworm eggs gently every 2-3 hours to make them dry as soon as possible and avoid their adhesion.The sterilized silkworm eggs should be dried in the shade as soon as possible to prevent direct sunlight. If necessary, they can be dried with an electric fan.
2 Packaging and transportation of silkworm eggs The eggs after disinfection and drying on the egg surface should be packaged in small egg containers for easy management, sales and transportation.Egg containers are mostly made of non-toxic plastic yarn, and can be made into specifications of 30cm × 20cm, 26cm × 16cm, etc. according to needs, with 0.5~1.0kg eggs in each bag.The middle of the large bag is sewed into several compartments with a sewing machine to prevent the accumulation of silkworm eggs from causing fever.[2]
