Cows like grain mostly since it's pretty easy energy. It's kind of like how we think of candy. But mostly they eat what's called silage. Silage is grass and hay

Cows like grain mostly since it's pretty easy energy. It's kind of like how we think of candy. But mostly they eat what's called silage. Silage is grass and hay which is primarily cellulose and a bit of chlorophyll. If a cow doesn't like something it won't eat it unless it is all you feed it. They are pretty deft at picking around stuff they don't like. (They do this when grazing too) As I understand it, the seaweed is just a supplement added to the silage and they voluntarily eat it when it's supplied. Cows aren't picky eaters. There was once a case where one was caught eating a python. But again, they are all unique individuals just like people. Some like stuff that others don't. Some get neurotic and eat rocks and dirt. I'm sure there are a quite a few cows that don't like seaweed but eat it anyways just for something to do. https://www.abc.net.au/news/2020-10-28/cow-eating-snake-photos-outback-australia/12822382 https://www.abc.net.au/news/2020-10-28/cow-eating-snake-phot...