The majority of cattle feed isn't hay or grass, but instead crops like Alfalfa or Soy. And in the end, it doesn't really matter, it's the underlying land use and it's impact that's relevant.

The feed conversion ratio for beef has the worst efficiency of all kinds of meat of 1:25.

This dataset by OWI is very enlightening when it comes to the types of our food and what kinds of different impact (landuse, animal feed, transport, ...) they have:

https://ourworldindata.org/grapher/food-emissions-supply-cha...