Beasts of burden is the name given to animals 动物 that
are exploited (used) by humans 人类 to do their
work. Examples of such animals are the donkey 驴, the camel骆驼
and the buffalo. They carry and pull loads for humans.
They also carry and pull humans. Humans domesticate
and train them so that these animals 动物
can do the heavy work and, thus, taking the burden off
humans.
Beasts of burden therefore have, among others, these
traits - they are strong and tough. They are also
easily "manageable".
Interestingly, the donkey 驴 is mentioned more than 80
times in the Bible. For example, as a mode of
transport, the donkey 驴 was ridden by
Jesus, Mary and Moses.
(Some scholars say that Jesus opted for the
donkey 驴
because the horse was perceived as a beast of
war.)