Disinfection technology of silkworm egg noodles

The purpose of egg surface disinfection is to kill the pathogenic microorganisms attached to the egg surface and avoid the disease caused by eating egg shells when the ant silkworm hatches. The disinfection of spring silkworm egg noodles should be carried out 1-2 days before silkworm emergence. Autumn silkworms had better be carried out in the afternoon one day before the emergence of silkworms, and go directly up the mountain to break eggs on that day.

First bathe the eggs with 0.5% sodium hydroxide aqueous solution, the liquid temperature is 18 to 20 ℃, wash the eggs for 1 minute, and remove the glue on the egg surface. Then rinse with clean water, control the moisture, and disinfect the egg surface. 36% formaldehyde solution, 36% concentrated hydrochloric acid and water were mixed into a mixture of 36% formaldehyde, 36% concentrated hydrochloric acid and water according to the ratio of 1 ∶ 0.5 ∶ 10, the liquid temperature was 23 ℃ and 25 ℃, and the eggs were soaked for 30 minutes. After removing the medicine with clean water for many times, spread it thinly on the plastic yarn to dry.

Formaldehyde solution produces trioxane precipitate at low temperature, which is insoluble in water and does not play a role in disinfection, so it cannot be used if it fails. Alcohol and mercury thermometers sold in the market are different in different degrees, so they must be corrected before use. The temperature of the solution should not be lower than 23 ℃. When the temperature is less than 23 ℃, the lower the temperature, the worse the effect. The disinfection of spring silkworm egg noodles often meets low temperature weather. In practice, the disinfection container is placed in warm water which is 1 / 2 ℃ higher than the solution temperature. Solution preparation order: add acid into the water and then add formaldehyde to mix well. During disinfection, the spring silkworm rubbed the eggs every 5 minutes to make the egg surface fully contact with the solution. Autumn silkworms should first cut off the four sides of the spawning paper to enhance the disinfection effect. At the same time, the egg blocks accumulated on the spawning paper should be rubbed off and put into gauze bags for disinfection. The key step of the disinfection operation is to take a piece of spawning paper, put the egg face down and put it in the liquid, gently press the back of the paper with both hands, wait for the whole spawning paper to be completely soaked, and then rise according to the same method until the end. One day before the spring silkworm comes out, the egg embryo has the silkworm shape and the breathing volume increases. The egg must be dried within 3 hours to avoid the egg pore being closed by water for a long time and make the embryo suffocate to death. People who come into contact with disinfection eggs should wear clean clothes in advance and wash their hands on the spot to prevent the egg surface from being infected by pathogenic microorganisms after disinfection.