He explains that producing genetically engineered proteins in the milk of pigs, cows, and sheep involves the direct modification of genes (gene transfer), a process with a long history. Its weakness is that large mammals take a very long time to mature, whereas silkworms go from incubation to the production of proteins in less than a month.
趙裕展指出，基因工程蛋白在豬、牛、羊的乳腺上，採直接改造基因（基因轉殖）的方式生產已行之有年，但缺點是這些大型哺乳動物繁殖非常耗時，而蠶寶寶從孵化到生產蛋白質，不到一個月的時間就能完成。