feed protein sources

• 蛋白质来源

feed protein sources的用法和样例：

例句

1. Fish eggs and meat are all major sources of protein.
   鱼类鸡蛋和肉类都是重要的蛋白质来源。
2. Wild mushrooms such as porcini or morels are a good source of protein as well.
   野生蘑菇例如牛肝菌和羊肚菌同样是好的蛋白质来源。