YMMV, but it's much more than 2.6% in the US. Livestock is 40% of of ag's GHG emissions.

https://cfpub.epa.gov/ghgdata/inventoryexplorer/#agriculture...

And ag is ~10% of US emissions

https://cfpub.epa.gov/ghgdata/inventoryexplorer/#allsectors/...

So eliminating livestock would reduce emissions by 4%.

With that said, 4% is still low, but it doesn't account for all the GHG emissions needed to grow feed for livestock, nor does it account for other things like transportation of that feed, energy used in processing by the industrial sector, and so on.