im going to add a caveat to that.
the general rule of single-target tanking is to always keep mangle and FF(feral) on cooldown. if your rage gen seems to be "ok" (as in you can keep mangle on cooldown but never seem to have more than say, 30 or 40 rage) then add in swipes periodically (assuming they wont break CC). swipe costs less than maul because maul uses up your next white hit, so any rage gained from that hit (unless you crit, which is an automatic +5 rage gain) is lost. therefore, if youre in a low-rage environment, using maul may hinder your ability to generate rage, which may hinder your mangle usage (and mangle is your biggest threat move).
should your rage gen exceed your ability to use swipe periodically plus mangle every time its up, then begin adding mauls in. should your rage gen outpace your ability to spend it by spamming maul, swipe and mangle, then youre probably going to die.