Discarded silkworm pupae can be used as high-nutritional-value livestock feed: CFTRI chief

Central Food Technological Research Institute (CFTRI) director Giridhar Parvatham has highlighted the potential of discarded silkworm pupae in serving as ‘high-nutritional-value’ livestock feed.

Speaking at the Reshme Krishi Mela organised jointly by Central Sericultural Research and Training Institute (CSRTI) and Department of Sericulture, Government of Karnataka, in Mysuru on Tuesday, Dr. Parvatham said silkworm cocoons consist of about 14-23% shell, which produces raw silk, while the remaining 80% is pupae, mostly discarded as waste.

“Dried silkworm pupae contain 55-60% protein, 30-35% lipids and smaller amounts of carbohydrates, vitamins and minerals. The lipids are a rich source of omega-3 fatty acids (a-linolenic acid), which are important for cardiovascular and brain health,” he said.

Dr. Parvatham said the abundant availability of feed resources, especially spent silkworm, should be utilised wisely while exploring unconventional feed options for livestock. In view of the rising prices of oilseeds and oilcakes, he said there was a need for a cost-effective and safe animal feed to meet the consumer demand for animal products.

In a year, India produces about 256,000 tonnes of wet pupae, which can serve as high-nutritional-value livestock feed and be used for preparing bypass protein and fat for fish and poultry.

Referring to a study undertaken to evaluate the use of silkworm pupae as an ingredient in poultry feed, the CFTRI director noted that up to 4% of cuticle-free pupae and 10.5% cuticle-free defatted pupae improved feed conversion ratio and body weight gain. 

“Histopathological studies revealed that whole silkworm pupae (with cuticle) adversely affected the small intestine’s mucosal and sub-mucosal lining while cuticle-free silkworm pupae showed little to no such effects. Research on mulberry silkworm pupae in layer feed shows replacing 2% to 4% of whole and cuticle-free pupae, or 10 to 21% of defatted pupae with soya meal, does not adversely affect egg production, weight or nutritional quality over 12 weeks,” he said.

Dr. Parvatham pointed out that the global silkworm cocoon market was experiencing a steady growth, driven by high demand for silk in textiles, cosmetics and biomedical applications with a projected market value surpassing $1.8 billion by 2033.

He said the industry was expanding at a CAGR of roughly 5-7%, with China and India dominating both production and consumption. India and China together produce almost 94-95% of the world’s raw silk. India is ranked second only to China and is followed by Uzbekistan, Vietnam, Thailand and Brazil.