苯基丙氨酸是酪氨酸的先质,而酪氨酸又是肾上腺素和非肾上腺素的先质,亦是甲状腺激素和三碘甲腺氨酸的先质.酪氨酸合成需要苯基丙氨酸,若饵料中的苯基丙氨酸含量低于鱼的最低需要量,酪氨酸即可进行补充.故鱼类对苯基丙氨酸的需要量受饵料中酪氨酸含量的影响,且因鱼类品种而异.如大鳞大麻哈鱼对苯基丙氨酸的需要量为饵料蛋白质的4.14%,对酪氨酸的需要量为0.98%;斑点叉尾(鱼回)的苯基丙氨酸需要量为饵料蛋白质的5.0%;鲤对苯基丙氨酸的需要量为饵料蛋白质的3.4%,对酪氨酸的需 Phenylalanine is a precursor to tyrosine, a precursor of epinephrine and non-adrenaline, and a precursor of thyroid hormone and triiodothyronine. Tyrosine synthesis requires benzene If the content of phenylalanine in the feed is lower than the minimum requirement of fish, tyrosine can be replenished, so the requirement for phenylalanine in fish is affected by the content of tyrosine in the feed , And vary according to the species of fish, for example, the requirement for phenylalanine for salmon is 4.14% for dietary protein and 0.98% for tyrosine; ) Of the phenylalanine requirement is 5.0% of the bait protein; carp for phenylalanine requirement is 3.4% of the bait protein, the need for tyrosine