A steer is a male bovine that has been castrated before reaching sexual maturity. Castration inhibits testosterone and aggression, making the males docile and safer to work with. Steers are raised for meat production and are less aggressive than bulls. They are normally less muscular than bulls, with smaller shoulders and heads. The weight of a steer varies depending on the breed, ranging from 450-1,360 kg (1,000-3,000 pounds). Steers may have horns, but some breeds are genetically polled (hornless), and others may be dehorned at a young age. Steers are trained to work as draft animals and are considered fully trained at the age of four.