US Patent 3,583,871 (granted June 8, 1971) describes an artificial feed for silkworms made from a hydrogel of maize and/or sorghum with soybean solids, which can replace mulberry leaves after the second instar. Examples compare feed compositions, cooking conditions, and particle size by larval weight and cocoon yield, and show that combining penicillin or tetracycline with a macrolide antibiotic protects larvae from flacherie. The patent ends with nine claims and a list of cited references. It was assigned to Ajinomoto Co. and Katakura Industry Co.

US Patent 3,488,196, granted 6 January 1970 to Masazumi Niimura, Jiro Kirimura and Noboru Katsuya, describes a method of raising silkworms on an artificial feed. Larvae are fed mulberry leaf material up to the second or third instar, then a feed with 20-60% protein and no mulberry leaf. Four examples with data tables compare larval growth, cocoon weight and cocoon layer weight against mulberry-leaf-only rearing, and the patent ends with four claims and cited references.