Conditions Required and Main Technical Requirements for Collective Rearing of Young Silkworms

I. The Purpose of Collective Rearing of Young Silkworms

As the saying goes: "Rearing young silkworms well is half the harvest," which fully illustrates the importance of rearing young silkworms. The purpose of collective rearing of young silkworms is to strengthen the constitution of young silkworms, ensure the safety of grown silkworms, and achieve high-quality and high-yield cocoons. Advantages of collective rearing of young silkworms: (1) It facilitates scientific @#@250@#@, adopts advanced silkworm rearing techniques and facilities, promotes uniform development and strong constitution of young silkworms, provides a guarantee for grown silkworm rearing, and lays the foundation for high and stable cocoon yields. (2) It facilitates disinfection and disease prevention. It overcomes the difficulties of young silkworms' weak resistance to adverse environments and susceptibility to pathogen infection, reduces lost silkworms, and ensures the number of silkworms. Collective rearing of young silkworms can achieve comprehensive disinfection of rearing rooms and equipment and strict disease prevention measures, reducing opportunities for pathogen infection and effectively controlling the occurrence of silkworm diseases. (3) It helps improve work efficiency. Collective rearing of young silkworms can save mulberry leaves, labor, fuel, equipment and housing, reduce silkworm rearing production costs, and improve economic benefits.

II. Conditions of the Collective Rearing Room

1. Establish a dedicated rearing room for young silkworms. Choose an independent location with a clean surrounding environment, fresh air, and no pollution. The collective rearing room for young silkworms needs good heat preservation and moisture retention, and should be equipped with dedicated rearing rooms, rearing equipment, and a mulberry leaf storage room. The collective rearing room and rearing equipment must not be used simultaneously for rearing grown silkworms. The surrounding environment must be able to be disinfected regularly; a disinfection pool should be set up at the entrance to the collective rearing area; the silkworm excrement pit must not be located outside the window of the collective rearing room on the upwind side, to prevent pathogens from being carried back into the rearing room by wind.

2. Establish a dedicated mulberry garden for young silkworms. The mulberry garden for young silkworms should strengthen water and fertilizer management (mainly compound fertilizer, organic fertilizer, and biological fertilizer) and pest control according to the characteristics of leaves used for young silkworms, to ensure the quality of leaves used for young silkworms.

3. Establish a strict management system. This includes work responsibilities, disease prevention and hygiene, quality inspection, and other management systems.

4. Establish a follow-up technical guidance team. Responsible for understanding the growth and development of young silkworms after distribution to farmers and the occurrence of silkworm diseases in the distribution area, and guiding farmers in proper rearing and disease prevention work.

5. Select dedicated collective rearing personnel who are skilled and conscientious. Staff in the collective rearing room must have a strong sense of responsibility, be skilled in rearing techniques, be meticulous, and master the characteristics and prevention measures of common silkworm diseases.

III. Main Technical Requirements for Collective Rearing

To rear young silkworms well, disinfection and disease prevention are the foundation, excellent varieties are the key, and careful rearing is the guarantee.

1. Establish, perfect, and strictly implement disinfection and disease prevention systems

Disinfection and disease prevention must run through all three production stages: before rearing, during rearing, and at the end.

(1) Disinfection before rearing

Following the principle of being comprehensive, thorough, and practical, the rearing room (mulberry leaf storage room) and rearing equipment should undergo "two disinfections, one washing, and one fumigation" - first disinfect, then wash, then disinfect again, and finally fumigate.

Disinfection: A bleaching powder solution containing 1% effective chlorine, or a mixture of 2-3% formalin and 0.5% limewater, can be used to spray and disinfect all surfaces of the rearing room. Disinfection must cover all six surfaces of the rearing room; after spraying, close the doors and windows and maintain a moist state for 30 minutes. For rearing equipment, immersion disinfection is best, generally soaking for 30 minutes. Attention should be paid to targeting the types of silkworm diseases that occurred in the previous season or year, conducting targeted disinfection, and carrying out disinfection in stages to be comprehensive and thorough. For viral diseases, use 2% lime slurry. For comprehensive disinfection, use strong chlorine powder, Du Xiaosan, bleaching powder, etc. To improve disinfection effectiveness, immersion disinfection should be no less than half an hour, spray disinfection should maintain moisture for half an hour, lime slurry should be used as a suspension, and bleaching powder should be used as a clarified solution.

Washing: This involves comprehensive washing of the rearing room and equipment. Points to note during washing: 1. Spray disinfectant before washing; 2. The water quality for washing must be good; it is strictly prohibited to wash rearing equipment in stagnant ditches, ponds, or by riversides; 3. Garbage and wastewater from washing must be kept away from the rearing room.

"One fumigation": Use Du Xiaosan to fumigate and disinfect the rearing room, equipment, and air in the rearing room. Fumigation disinfection should be sealed for more than 24 hours (at 24°C). Du Xiaosan must fully generate smoke.

In summary, disinfection and disease prevention before collective rearing should focus on creating a non-toxic or low-toxicity environment. For disinfection of rearing rooms and equipment, the key is cleaning, washing, disinfection, and sun exposure. In particular, new rearing equipment must be fully sun-exposed; only after disinfection and drying can it be brought into the room. After disinfection, rearing rooms and equipment must be protected from re-contamination by pathogens. While disinfecting the rearing room and rearing seats, the outdoor surrounding environment should also be disinfected.

(2) Disinfection and disease prevention during rearing

In collective rearing of young silkworms, "disinfection and disease prevention" must be implemented throughout the entire production process. In addition to the above-mentioned pre-rearing disinfection, disinfection during the rearing period is also key. First, do a good job of cleaning and hygiene in the collective rearing room; second, strictly disinfect the rearing room and equipment; third, strengthen disinfection of silkworm bodies and rearing seats. During the rearing period, pathogens and viruses in the rearing room will gradually accumulate as they are brought in by personnel, mulberry leaves, and air. Therefore, during disinfection and disease prevention, the following must be observed:

Upon entering the rearing room, first wash hands, change into work clothes, and wear a work cap properly. Observe "three hand-washings": wash hands before entering the collective rearing room, wash hands before cutting mulberry leaves and feeding, and wash hands after removing excrement and spreading the rearing seats. "Two shoe changes": change shoes when entering the rearing room, change shoes when entering the mulberry leaf storage room. "One cleaning": indoor shoes and the rearing room, mulberry leaf storage room, and their entrances should be rinsed with clean water daily and disinfected with 1% bleaching powder solution. After each feeding and excrement removal, promptly sweep the floor of the collective rearing room, and disinfect with 1% bleaching powder solution once daily. When humidity is high, place un-slaked quicklime in the four corners of the rearing room to absorb moisture. Set up a disinfection vat in the rearing room; weak and diseased young silkworms should be placed in the vat for disinfection before being dumped into the silkworm excrement pit, to prevent pathogen spread.

Disinfection of silkworm bodies and rearing seats. Disinfectants must be considered for silkworm safety, used according to standards, and not abused to avoid drug damage and waste. Commonly used drugs include: fresh lime, "Disease Prevention No. 1," anti-stiffening powder, etc. For young silkworms, at the start of ant collection, sprinkle "Young Silkworm Disease Prevention No. 1"; thereafter, use "Young Silkworm Disease Prevention No. 1" once at the start of each instar. When stiffening disease occurs, use anti-stiffening powder once daily; after recovery, use the drug once every two days. The drug must be sprinkled on the back and abdomen of each silkworm. 5-10 minutes after sprinkling the drug, sprinkle bedding separation material, then feed mulberry leaves. Targeted treatment should be strengthened according to climate and rearing room environment. For example, when humidity is high, add fresh lime powder; when mulberry garden pests frequently develop stiffening disease, strengthen anti-stiffening treatment and use more anti-stiffening powder. At the end of each instar's feeding, fresh lime powder must be used once. During each instar's feeding period, sprinkle fresh lime powder or "Young Silkworm Disease Prevention No. 1" once daily, or use them alternately, to prevent silkworm diseases. When collective rearing is about to end and young silkworms are being distributed, conduct disinfection of silkworm bodies and rearing seats once before distribution, i.e., sprinkle "Young Silkworm Disease Prevention No. 1," with the amount used appropriately on the higher side. After farmers receive the young silkworms, they should immediately use "Young Silkworm Disease Prevention No. 1" again for disinfection. "Young Silkworm Disease Prevention No. 1," lime powder, and anti-stiffening powder must be fresh, opened and used immediately, to ensure drug effectiveness.