I bought two cows and now I have four. As far as I know I don’t have a bull. What happened? Does disable milking cause this?
it does not specify the gender of your cattle in game, it just generically calls them “cows”
if you have two or more it assumes you have at least one male
oooh I see! That’s useful then 
Um is there a way to select which gender you slaughter as I’d want to slaughter bulls rather than cows for obvious reasons. Or will the game assume I’ve managed to keep one of each right down to the final two?
Again, it doesn’t track the gender of your cattle. as long as you have 2 or more they will multiply.