A cow eating grass isn't eating sequestered carbon. It's part of the carbon cycle. It is a living organism eating a living plant. If a ruminant doesn't graze a grassland, it needs to burn...which releases carbon. If neither one of those things happen, the grassland will die and decompose.

Grasslands and ruminants co-evolved.

Sequestered carbon would be underground. If there were no fossil fuels dug out of the ground and burned, there are no amount of cows that could cause a problem with warming.

ALL ruminant animals produce methane. Deer, moose, elk, antelope all do. It is part of fermentation.

A cow eating grass is more carbon neutral than other things people try to pass off like biodiesel.

True, although research is ongoing into minimising this[1] and a product based on the above research is being prepared for the market.

[1]: https://journals.plos.org/plosone/article?id=10.1371/journal...