We were watching 
Robert Schimmel on TV last night.  He did a quite hilarious routine which included a sketch about a man who had been convicted of "necrobestiality" - in his case, the suspect was discovered attempting sexual intercourse with a dead cat.
So what makes necrobestiality what it is?  While gunge involves sex play using food products, it is not considered illegal.  It would not be a crime to involve strips of bacon in sex or masturbation, but the intact corpse of a freshly-killed pig would be off-limits.  Where is the dividing line? 
Suppose you chopped the head off of a dead pig.  Would it be legal to involve it in sex play then?  Or what if you cleaned and roased a dead cat with Shake N' Bake?  Would it become food?  I am mystified by this problem.  While I considered questioning a local police desk sergeant over the phone (with anonymous precautions taken), it occured to me that perhaps the police are not the correct people to ask.  The answer a policeman will give indicates what he will or will not arrest people for - but it is prosecutors and judges who really control the law.  However, even legal authorities must turn to philosophy in order to interpret the legal question as to what makes a dead animal a dead animal and not food - and I request your opinion accordingly.