"Donkey", "Donkey" is a symbol of people, their obedience, endurance, unpretentiousness, lack of pride, aggressiveness, militancy, people who tolerate everything from those rulers who "ride" on them, exploit their intellectual and physical capabilities and features.
"Donkey" is a characteristic of man - uncomplaining, enslaved by religious, political and other fanaticism, staying under the oppression of false religious leaders, predatory political rulers.
"Donkey" also symbolizes the sinfully enslaved state of man, who is "bound" to the sinful desires of the flesh, stubborn, indomitable in lusts.