In the Samyuta Nikaya (111,1-9) we have another description of a Yajna performed by Pasenadi, king of Kosala. It is said that five hundred bulls, five hundred calves and many heifers, goats and rams were led to the pillar to be sacrificed. Also see...Ramayana 2:20, Ramayana 4:17:34., Visnusmrti 51:6, Rigveda (10/85/13) , Rigveda (6/17/1)