The bull or bullock is the adult male of the genus Bos (Bos taurus or Bos taurus). In general, the bull is uncastrated and has a functional testis. On the other hand, a bullock is castrated and testicles are removed. Due to the absence of functional testicles, the testosterone level in the blood of bull is reduced. therefore, the bullock is docile compred the bull.
Bulls are fertile and can be used in the and due to the absence of functional testicles, They can breed and produce calves. On the other hand, oxen are castrated. They are infertile and cannot take part in breeding.