Throughout much of the novel, Loyd is a self-identified rooster-fighting man. In the one and only conversation we get to witness between Codi and J.T, who is Loyd's best friend, Loyd explains exactly why cockfights are so important to a laid-back guy like him.
Basically, it's his one inheritance from his father. Loyd's dad was a legendary cockfighter in Apache country, and because he was also a drunk and a ne'er-do-well, "Loyd's old man didn't have one damn thing to give him but cockfighting" (11.18). Later, when we actually get to see a cockfight, it's useful to remember that the sport is understood as something that is passed from father to son. Codi describes the fight as "frankly sexual. Each time the men's hips rocked forward, the cocks dutifully bit each other's faces" (16.135).
Whoa, hey there. Tone it down, okay? We've got students here.
In addition to being bizarre and hilarious, this image magnifies the way that cockfighting stands in for a masculine tradition. We think it's fair to say that that tradition is undermined in Animal Dreams, where it comes to be seen as a violent, shortsighted, and ultimately inadequate inheritance.
Loyd gives up the sport because he sees a link between its violence and his twin brother's early death. Instead of an inheritance from his father, Loyd opts for the inheritance of a peach orchard from his aunt. Symbolically, the rejection of cockfighting in Animal Dreams seems to be a rejection of patriarchal inheritance as a whole in favor of a kind of matriarchy.