When you are entering culls and deaths of sows and gilts there is an exit type box you use this to register if the sow/gilt has been for example sold (culled), slaughtered or euthanizedWhen entering the date, it is possible to choose which type of exit happened for the given sow/gilt.  

Then under "Analysis sows" you can make a "Customized analysis" about "Removal reasons sows" and see if one of the exit types is seen more often than others.