Original sentence: Critics contend these 'lost' horses are killed.Proponents of the support claim that they are used in breeding, sold to hunters who ride horseback, and for point-to-pointing (another horse sport)
Edited sentence: Critics, based on rumour, contend these 'lost' horses are killed, but in actuality they are used in breeding, sold to hunters who ride horseback, and for point-to-pointing (another horse sport)