Human milk is different from cow's milk. Cows ingest grass, and humans ingest processed and whole foods (That are not grass). This plays a role in it; also the fact that human milk contains more polyunsaturated fat and monounsaturated fat, as well as less calcium than cow's milk. Also, babies are able to live without human milk throughout their infancy (that probably sounded less than coherent but i'm not on my A game anyways🤓).