Disinfection and hygiene

Last modified at 24/08/2016 13:41 by System Account

Disinfection and hygiene

Disinfection is the important necessary step to ensure healthy and successful silkworm rearing. It aims at total destruction of disease causing pathogens. Several bacteria, virus, fungi and protozoans cause silkworm diseases. These pathogens released by diseased silkworms easily accumulate and spread in the environment. They can survive for long periods under congenial conditions. The spores of pathogens like fungi are very light and easily carried by wind and can spread from one rearing house to another. There are no curative methods for any silkworm diseases, therefore, prevention of the disease is the best cure. Prevention of the disease is ensured by proper disinfection and maintenance of hygiene.

  1. Chemical disinfectants used in Sericulture:
    1. Formalin
      It is commercially available as 36% formaldehyde solution. A mixture of 2% formalin + 0.05% detergent is an effective solution that can be used for disinfection purpose. Formalin is effective only if the rearing house can be made airtight.
    2. Bleaching powder.
      For an effective disinfection, a high grade bleaching powder with 30% active chlorine content must be used. It should be stored in sealed bags away from moisture. Under wet and contact conditions the action of bleaching powder is very effective. Therefore surface and the walls should be drenched with this solution. A 2% bleaching powder in 0.3% slaked lime solution is used for disinfection as spray.
    3. Slaked lime.
      Slaked lime is a very effective bed disinfectant, especially against virus. It absorbs moisture and can b used to regulate bed humidity and maintain hygiene. Application of lime dust in combination with bleaching powder in and around rearing houses and premises improve hygiene in the environment.
    4. Chlorine dioxide.
      Chlorine dioxide is marketed as Sanitech and is an ideal disinfectant for Sericulture. The disinfectant available at 20,000 ppm concentration is a strong oxidizing agent. It is stable and can be activated at the time of disinfection. It has a characteristic odour and non-corrosive at the suggested dilution.
  2. Materials required for disinfection

    Disinfectants, detergent, sprayer ( Rocking, Gator, power sprayer or multipurpose pump), buckets measuring jars, weighing scale, gas mask, metal pans, room heaters, hand glove and muslin cloth.

  3. Hygiene
    1. Cleaning of rearing houses and appliance
      Immediately after the completion of the silkworm rearing and disposal of the cocoons, all the refuse of the rearing including dead larvae and pupae should be gathered in one place inside the rearing house. Disinfect the rearing house including this debris with 5% bleaching power solution and later dispose the debris by burning or burying 2 ft deep.
      Disinfection process should start 4-5 days prior to brushing. However, the eggs may be incubated in a separate disinfected room.
    2. Calculating the area of rearing house.
      Floor area = Length x Breadth ( of the floor) Example: Length=20�, breadth =15� Area=20x15=30 sq ft =28 m2
    3. Estimation of quantity of disinfectant required.
      1. Solution required for spraying inside the rearing house
      2. Solution required to disinfect appliances inside the rearing house= 25% of a.
      3. Solution required for spraying outside side the rearing house= 10% of a.
      4. d. Total solution required =a+b+c. 2 lt/sq mt or 185 ml/sq ft floor area is required.

      For above example,

      1. 28 x 2= 56 lt of solution is required for disinfection inside the rearing house
      2. b. 56x 25%=14 lt solution is required for disinfection of appliances.
      3. 56 10% = 5.6 lt solution is required for disinfection outside the rearing house.
      4. d. Total solution required = 56+14+5.6= 75.6 lt =75 lt.
  4. Disinfectants
    1. 2% belching powder in 0.3% slaked lime, or
    2. 2.5% sanitech (Chlorine dioxide) in 0.5% slaked lime, or
    3. 2% Formaline + 0.05% detergent solution.
    4. Preparation of bleaching powder solution: 20g bleaching powder and 3 g slaked lime in one lt is 2% solution. To prepare 75 lt solution, 75x20=1.500 kg bleaching powder + 75x3=225 g of slaked lime is required.
    5. Preparation of 2.5% sanitech. Preparation of 1 lt Sanitech, Solution A: Add 2.5 g of activator crystals to 25 ml of sanitech solution, stir and allow for 5 inutes to stand. Lor hanges to light yellow. Solution B: Mix 5 g of slaked lime powder in water and make it up to 975 ml of water. Mix solution A and Solution B.
      To prepare 75 lt of sanitech in 0.5% slaked lime solution, Solution A: 75 x 25= 1.875 lt sanitech concentrate solution+ 75.x 2.5=187.5 g activator. Solution B: 75 x 5 =375 g slaked lime Mix and add 75-1.875=73.125 lt water
    6. Preparation of 2% Formalin solution: One part of 36% formaldehyde solution = 17 parts of water is 2% formaline solution. Add 05 g detergent per liter of Formalin. To prepare 75 lt of 2% Formalin, 75/17=4.17 lt. Take 4.17 lt Formaldehyde solution and add 75-4.17=70.59 lt of water. Add 75 x 0.5 = 3.75 g of detergent.

Disinfection and hygiene

Disinfection is the important necessary step to ensure healthy and successful silkworm rearing. It aims at total destruction of disease causing pathogens. Several bacteria, virus, fungi and protozoans cause silkworm diseases. These pathogens released by diseased silkworms easily accumulate and spread in the environment. They can survive for long periods under congenial conditions. The spores of pathogens like fungi are very light and easily carried by wind and can spread from one rearing house to another. There are no curative methods for any silkworm diseases, therefore, prevention of the disease is the best cure. Prevention of the disease is ensured by proper disinfection and maintenance of hygiene.

  1. Chemical disinfectants used in Sericulture:
    1. Formalin
      It is commercially available as 36% formaldehyde solution. A mixture of 2% formalin + 0.05% detergent is an effective solution that can be used for disinfection purpose. Formalin is effective only if the rearing house can be made airtight.
    2. Bleaching powder.
      For an effective disinfection, a high grade bleaching powder with 30% active chlorine content must be used. It should be stored in sealed bags away from moisture. Under wet and contact conditions the action of bleaching powder is very effective. Therefore surface and the walls should be drenched with this solution. A 2% bleaching powder in 0.3% slaked lime solution is used for disinfection as spray.
    3. Slaked lime.
      Slaked lime is a very effective bed disinfectant, especially against virus. It absorbs moisture and can b used to regulate bed humidity and maintain hygiene. Application of lime dust in combination with bleaching powder in and around rearing houses and premises improve hygiene in the environment.
    4. Chlorine dioxide.
      Chlorine dioxide is marketed as Sanitech and is an ideal disinfectant for Sericulture. The disinfectant available at 20,000 ppm concentration is a strong oxidizing agent. It is stable and can be activated at the time of disinfection. It has a characteristic odour and non-corrosive at the suggested dilution.
  2. Materials required for disinfection

    Disinfectants, detergent, sprayer ( Rocking, Gator, power sprayer or multipurpose pump), buckets measuring jars, weighing scale, gas mask, metal pans, room heaters, hand glove and muslin cloth.

  3. Hygiene
    1. Cleaning of rearing houses and appliance
      Immediately after the completion of the silkworm rearing and disposal of the cocoons, all the refuse of the rearing including dead larvae and pupae should be gathered in one place inside the rearing house. Disinfect the rearing house including this debris with 5% bleaching power solution and later dispose the debris by burning or burying 2 ft deep.
      Disinfection process should start 4-5 days prior to brushing. However, the eggs may be incubated in a separate disinfected room.
    2. Calculating the area of rearing house.
      Floor area = Length x Breadth ( of the floor) Example: Length=20�, breadth =15� Area=20x15=30 sq ft =28 m2
    3. Estimation of quantity of disinfectant required.
      1. Solution required for spraying inside the rearing house
      2. Solution required to disinfect appliances inside the rearing house= 25% of a.
      3. Solution required for spraying outside side the rearing house= 10% of a.
      4. d. Total solution required =a+b+c. 2 lt/sq mt or 185 ml/sq ft floor area is required.

      For above example,

      1. 28 x 2= 56 lt of solution is required for disinfection inside the rearing house
      2. b. 56x 25%=14 lt solution is required for disinfection of appliances.
      3. 56 10% = 5.6 lt solution is required for disinfection outside the rearing house.
      4. d. Total solution required = 56+14+5.6= 75.6 lt =75 lt.
  4. Disinfectants
    1. 2% belching powder in 0.3% slaked lime, or
    2. 2.5% sanitech (Chlorine dioxide) in 0.5% slaked lime, or
    3. 2% Formaline + 0.05% detergent solution.
    4. Preparation of bleaching powder solution: 20g bleaching powder and 3 g slaked lime in one lt is 2% solution. To prepare 75 lt solution, 75x20=1.500 kg bleaching powder + 75x3=225 g of slaked lime is required.
    5. Preparation of 2.5% sanitech. Preparation of 1 lt Sanitech, Solution A: Add 2.5 g of activator crystals to 25 ml of sanitech solution, stir and allow for 5 inutes to stand. Lor hanges to light yellow. Solution B: Mix 5 g of slaked lime powder in water and make it up to 975 ml of water. Mix solution A and Solution B.
      To prepare 75 lt of sanitech in 0.5% slaked lime solution, Solution A: 75 x 25= 1.875 lt sanitech concentrate solution+ 75.x 2.5=187.5 g activator. Solution B: 75 x 5 =375 g slaked lime Mix and add 75-1.875=73.125 lt water
    6. Preparation of 2% Formalin solution: One part of 36% formaldehyde solution = 17 parts of water is 2% formaline solution. Add 05 g detergent per liter of Formalin. To prepare 75 lt of 2% Formalin, 75/17=4.17 lt. Take 4.17 lt Formaldehyde solution and add 75-4.17=70.59 lt of water. Add 75 x 0.5 = 3.75 g of detergent.

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