Investment breakthrough: Rhoda starts producing silkworm eggs

Rwanda Horticulture Development Authority (Rhoda) scientists have managed to produce 75.55 Kg of silkworm eggs in the country.

Sunday, April 20, 2008

RWANDA Horticulture Development Authority (Rhoda) scientists have managed to produce 75.55 Kg of silkworm eggs in the country.

The breakthrough may see government stop importing the eggs of the worms therefore saving millions of tax payers’ money. When produced in plenty, it is hopped the only local textile factory will be assured of constant supply of raw materials.

Importing silkworm eggs from South Korea and India has been very expensive and also risky, Rhoda officials said. At times the eggs would be hatched and lose viability in transit.

To import a box of silkworms eggs, government has been spending $15 to $20 (about Frw11,000 to Frw8,000) on each, meaning if government imports 35,000 boxes, then Frw383.6 million is spent.

Belline Mukasake, head of the seed development in Rhoda said the eggs will be supplied to Utexrwa, the only textile factory in the country, free of charge.

To stock all cooperatives involved in silkworm farming countrywide, Rhoda plans to produce 700 million silk worm eggs.

Government allocated about Frw154m particularly for training. And 60 trainers were taught various sericulture activities including mulberry farming, silkworm egg rearing, weaving to ensure that they produce quality silk products.

With Rwanda’s excellent agro-climatic conditions that favour an all year round silk production, at least 600,000 hectares of mulberry are planned to be planted to sustain silk production in the next three years.

"I am told that returns from silk are two times higher than that of coffee and three times than tea," said Mukasake.

Silkworm

Internet information shows that sericulture or the raising of silkworms involves the incubation of the tiny eggs of the silkworm moth until they hatch and become worms. After hatching, the worms are placed under a layer of gauze, on which is spread a layer of finely chopped mulberry leaves. For six weeks, the worms eat almost continuously. At the end of this period, they are ready to spin their cocoons, and branches of trees or shrubs are placed in their rearing houses. The worms climb these branches and make their cocoons in one continuous thread, taking about eight days for the process. The amount of usable silk in each cocoon is small, and about 5,500 silkworms are required to produce 1 kg (2.2 lb) of raw silk.

Processing

After the complete cocoons have been gathered, the initial step in silk manufacture is to kill the insects inside them. Thus, the cocoons are first boiled or treated in ovens, killing the insects by heat. The silk fiber is obtained from the cocoons by a delicate process known as reeling, or filature. The cocoons are first heated in boiling water to dissolve the gummy substance that holds the cocoon filament in place. After this heating, the filaments from four to eight cocoons are joined and twisted and are then combined with a number of other similarly twisted filaments to make a thread that is wound on a reel. When each cocoon is unwound, it is replaced with another cocoon. The resulting thread, called raw silk, consists usually of 48 individual silk fibers. The thread is continuous and, unlike the threads spun from other natural fibers such as cotton and wool, is made up of extremely long fibers. Along with cocoons damaged by emerging worms used for breeding stock, the filaments from the coarse outer portion of the cocoon, which is removed by brushing before reeling, and the inner portion of the cocoon, which remains after reeling the raw silk, are mixed to produce a low grade of silk staple that is spun into yarn.

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