Lupe: I can't wait to show you to the rest of the guys! They're gonna fertilize the yard.
Una: I'm Una...
Dos: I'm Dos...
Cuatro: And I'm Cuatro.
Ferdinand: What happened to Tres?
Una: We do not speak of Tres.
Lupe: Look at your pecs! They're like two tiny bulls inside a bull.
Lupe: It's a dog-eat-dog, bull-fight-bull, everyone-hates-on-the-goat world.
Lupe: Holy Beefaroni! You're ginormous.
Answer: There could be any number of reasons. The owners may have felt that just letting the bulls go was the morally right thing to do without profiting from it.