late age rearing technology

1. LATE AGE SILKWORM REARING

2. AIM OF XII th FIVE YEAR PLAN
(2012-13 to 2016-17)
Increase the production of Quality raw
silk at lower cost of production.
Why Production To meet out the
domestic requirement of raw silk
By the end of 11th plan (2011-12)
Requirement: 28,733 MT
Production: 23,060 MT
Import: 5,700 MT (>2A grade)

3. Why Quality:
 Cutting down the import of silk
 Meet the demand of domestic power looms
 Enable to compete in the world market
 Increase the income generation of
stakeholders
Why low cost of production:
 Increase the net income of stakeholders
 Enable to compete in the world market

4. Raw material for the production of raw silk :
Cocoon: Quality of it alone contributes 80 %
of success in the production of quality silk.
So silkworm rearing is one among the
important operations in the production of
quality cocoons

5. EMPHASIS OF REARING
Chawki: Reduce the number of missing
larvae and develop resistance power.
Late age :Enhancing the quality and
quantity of silk produced by the silk
worm
So the ecological and nutritional
requirements in late age are differ from
young age and hence the success of silk
worm crop depends on understanding
the requirement and manage them.

6. Characteristics of late age silkworms
 They require cooler and drier climate
 They are voracious eaters and consume large
quantity of leaf (98 % of the total)
 Increase body volume by 133 times, weight by
125 times and silk gland weight by 1000 times
 They require mature leaves with less water
content and more protein and crude fibres
 Sensitive to pathogens and unfavourable
conditions ( High temperature, high humidity,
poor ventilation, in sufficient food and tender
leaves)

7. HOW TO REAR:
 Rear the silkworms under pathogen free and
controlled environmental conditions.
 Provide them quality food and space

8. Tips for successful Silkworm rearing
1. Ensure disinfection before and after rearing
2. Maintain hygiene during rearing
3. Much amount of quality leaf
4. Pathogen free young age larvae
5. Adequate spacing specially during 5th age
6. Mounting in good ventilated place with
good mountages
7. Ensure good rearing environment

9. DISINFECTION
Why disinfection:
1. Use of exotic origin breeds
2. Productive breeds are more susceptive
3. High pathogen load in the environment
4. No disease control only prevention
How it can be done:
1. Sun dry the equipments
2. Wash the equipments in 2% BP + 0.3%
lime
3. Spray 2%BP+0.3% lime Or 2.5% ClO2 +
0.5 % lime Or 0.05% Asthra @ 1.5 l/Sq .m
floor area

10. REARING HYGIENE
Why Hygiene:
1. To avoid entry of pathogens
- By dusting 5% BP in lime (1:19 ratio)
2. To avoid multiplication of pathogen in the
rearing house
- By dusting bed disinfectants as per the
recommended schedule

11. REARING HOUSE
 Separate, with good ventilation located in the
vicinity of the mulberry garden or near to the
garden.
 Windows face North and south to avoid direct
entry of sun light.
 Ventilators should be on above and below the
windows for air circulation.
 Asbestos roof, cement floor with 10-15 cm
deep channel inside all around the rearing
house to avoid ants and drain out water at the
time of cleaning and disinfection and also cool
the rearing house duringf summer.

12. • Shoot rearing rack should have 4-5 tier system
• Rearing rack width should be 5-5.5 ft
Width should be : 18-20 ft.
Length : Width: 18 - 20 ft
Length: As per the requirement
a. 0.2 x No. of Dfls + 10 (4 tier)
b. 0.16 x No. of Dfls + 10 (5 tier)
Ex: 0.2 x 150 + 10 = 40 for 1 acre (10 crop schedule)

13. SHOOT REARING
 Effective for labour saving – 43 %
(Leaf harvest- 70 %,Feeding -20 % and
Bed cleaning - 50 %)
Saves time and 20 % Leaf
Maintain leaf quality during preservation
and on the rearing bed
Litter is always separated from larvae and
minimize the handling of silkworms avoids
secondary contaminations

14. No bed cleaning helps to maintain
hygiene
Disease and weak larvae do not climb
up but remains below automatically
separated from healthy larvae and
hence created hygiene environment
Less cost of production, high quality
and quantity production

15. 25`x 5.5`x 4 tiers
15`x10`
Leaf room
5` x 10`
Ante room
25`x 5.5`x 4 tiers
Verandah
verandah
30`
20`
W
V
D
10 `
W = Window, V = Ventilator, D = Door
D
Length of rearing hall = 0.20 x No. of dfls + 10 = 0.20 x 300 + 10 = 70
Breadth (Constant) = 20 feet Leaf preservation room = 15 x 10
Anteroom = 5 x 10 Total bed area = 25 x 5.5 x 4 x 4 = 2,200 sq.ft .
Bed area/100 dfls = 733 sq.ft.
25`x 5.5`x 4 tiers
25`x 5.5`x 4 tiers
D
D
D
D
30`
MODEL REARING HOUSE FOR REARING 300 dfls/CROP (2 Acres)

16. ENVIRONMENTAL CONDITIONS
Temperature: 24-26°C±4-5 °C (i.e 20-30 °C )
Humidity: 75 ±5% (i.e 70-80 % )
Aeration: 1m/S
Light: 16 h light and 8 h dark
Management : High temperature,
Low/high humidity and poor ventilation

17. Effect of high temparature
Growth becomes fast, larva begins to spin
the cocoons prematurely, even before
eating their full quota of food and
therefore the cocoons spun are small in
size with less silk content and some
times prone to disease by multiplication
of pathogens .
Indirectly it affects the quality of leaf in
the rearing bed due to driage

18. Effect of low humidity: Drying of leaf in
the bed , larva donot eat sufficient food,
growth becomes reduced and ultimately
prone to disease
Effect of High humidity: Stressed to
silkworm and multiplication of
pathogens

19. Aeration
Why: It is essintial to drive out gases such as
CO2, NH4 and others released in the rearing
bed by the respiratory activity of the
silkworms and the decomposition of litter.
Effect of Low Areation: Built up humidity and
accumilation of poisnous gases like CO, CO2,
NH4 etc. which adversely affects the growth of
silkworm and make them suceptible to disease
besides affecting on larval weight, cocoon
weight and pupation

20. Management of High temparature &
Low humidity (Summer)
Ventilations should be increased through
bottom ventilators to expel the inside
heat and reduce temperature.
Wet ganney bags are hung inside the
room and water sprinkled on the leaves,
walls and floor of room to increase the
humidity and reduce the temperature.

21. Management of High humidity
Ventilations should be increased to expell
moisture.
Sprinkle lime powder on the rearing bed
and in the corners of the room.

22. MULBERRY LEAVES FOR LATE AGE
They require mature leaves with less
water content, more protein and crude
fibres. Obtained from well maintained
plantation having 55-60 days old
Harvest and transport: Cooler hours of the
day
Preservation: Arrange vertically in upward
direction and wrap with wet gunny cloth
Sprinkle water directly on to the shoot to
reduce evaporation during summer.

23. AMOUNT OF FEED (50,000 eggs)
III : 25+50+50+15 = 140 (4 %)
IV : 60+120+150+130= 460 (13 %)
V:220+310+460+560+700+410+220=2880
(83 %)
TOTAL : 3480 kg
Frequency: 2-3 /day

24. SPACING (50,000 eggs in Sq.ft))
III – 100-200 (800-260 larvae/sq.ft)
IV – 200-400 (260-140 larvae/sq.ft)
V – 400-800 ( 140-70 larvae/sq.ft)

25. MOUNTING
1. Identification of matured larvae
2. Type of mounting
3. Density of mounting
4. Environment conditions
(T: 24±0.5 °C; H: 65 ±5%; Air: 1 m/s)
5. Time of harvest
6. Cleaning and mode of marketing

26. Combined effect of temperature, relative humidity and air
flow during cocooning on reelability of cocoons
Tempera
ture(°C)
RH(%) Reelability ( % ) in relation to
airflow
0 m / Second 1.0 m / Second
23 65 92 96
90 54 91
30 65 85 94
90 28 83