Mangle from another druidFollow

I recently started Kara runs and sometimes I'm the main tank and sometimes I'm dps. When I am dps usually the MT is another druid. Maybe I'm wrong but I assume that mangle from the other druid still provides 30% additional damage from shred and bleed effects from me, correct? So would it be best to just continue to shred a mob til 5 points as long as threat is not factor and the MT keeps hitting with mangle?

I wasn't certain about that, but thank you for answering a question I never asked :)