In Sri Caitanya Caritamrita adi lila, chapter 17 verse 166 Caitanya Mahaprabhu confirms:



go-ange yata loma tata sahasra vatsara

go-vadhi raurava-madhye pace nirantar

Cow killers and cow eaters are condemned to rot in hell for as many thousands of years as there are for each hair on the body of every cow they eat from.



�chaitanya-mangala’ shune yadi pashandi, yavana

seha maha-vaishnava haya tatakshana



If even a great atheist hears Shri Chaitanya-mangala (previous name for Shri Chaitanya-bhagavata), he immediately becomes a great devotee.