The most extravagant venationes occurred at the dedication of the Colosseum by Titus, when there was a naumachia, gladiatorial combat, and the exhibition of "five thousand wild beasts of every kind in a single day" (Suetonius, Titus, VII.3), and in the games celebrated by Trajan, after his victories over the Dacians, "in the course of which some eleven thousand animals, both wild and tame, were slain, and ten thousand gladiators fought" (Dio, LXVIII.15).
The Historia Augusta records that, at the millennium of Rome's founding (AD 248), Philip I (the Arab) displayed thirty-two elephants, ten elk, ten tigers, sixty tame lions, thirty tame leopards, ten hyenas, a hippopotamus and a rhinoceros, ten "archoleontes," ten camelopards (giraffes), twenty onagri (wild asses), forty wild horses, and a variety of other animals (Gordian, XXXIII).
In AD 281, in venationes celebrating the victories of Probus, a thousand ostriches, a thousand stags, a thousand boars, as well as "deer, ibexes, wild sheep, and other grass-eating beasts, as many as could be reared or captured" were released in the Circus, which had been planted to look like a forest. The populace then was admitted and allowed to take whatever they could capture. Another day, in the Colosseum, one hundred male lions, their roars sounding like thunder, were released.
"All of these were slaughtered as they came out of the doors of their dens, and being killed in this way they afforded no great spectacle. For there was none of that rush on the part of the beasts which takes place when they are let loose from cages. Besides, many, unwilling to charge, were despatched with arrows."
One hundred Libyan and one hundred Syrian leopards, one hundred female lions, and three hundred bears then were killed, "all of which beasts, it is clear, made a spectacle more vast than enjoyable" (Probus, XIX).
"But what pleasure can it possibly be to a man of culture, when either a puny human being is mangled by a most powerful beast, or a splendid beast is transfixed with a hunting-spear?" (Cicero, Letters to Friends, VII.3). - http://penelope.uchicago.edu/~grout/encyclopaedia_romana/gladiators/venationes.html