Angus has short horns, despite the fact that his cattle-breed, Scottish Highland-cattle, has long and wide horns.
When Ferdinand asks the hedgehogs what happened to Tres, the hedgehogs make the sign of the cross but Una the female hedgehog does it with her left hand. In the Catholic religion, the sign of the cross is always done with the right hand.
Ferdinand is given his name from birth, when he is being raised at the bull camp. He then runs away and is adopted by a new family, but how does this new family know that is name is Ferdinand? He was not wearing any identification tags, and he clearly couldn't speak to the humans to tell them this. But given that the bulls never spoke human in the first place, all their English lines are translated, Ferdinand is just the name given in translation.
Maquina has long and wide horns, despite the fact that his cattle-breed, Belted Galloway, is naturally polled (hornless). His horns may be a result of his presumed artificial genetic processes.
The trains are fitted with Janney couplers, which are not used in Spain. Instead, European trains in general use the buffers and chain couplers.