The Avestan word pasu
Word pasu
Meaning cattle, livestock
See also Proto-Indo-European: *pék̂u ‘livestock’

Other words that might be of interest
spa(n) ‘dog’, aspa ‘horse’, gauu- ‘cow, bull’, vəhrka- ‘wolf’, sūn- ‘dog’, uštra- ‘camel’, būza ‘male goat, goat’