The Nali race has been long enslaved and dominated by the Skaarj. A newly formed Nali faction has repented their pacifist ways and has rebelled against the Skaarj, and they're ready to prove their combat skills in the Tournament.
When the militant Nali were driven from their homeworld they brought the only domesticated beast they knew of- their local livestock. By using Pavlovian techniques and heavy cerebral modification they are training their cattle to fight instead of graze.