Chaka, the Frankenstein reference was just a colourful metaphor, lost on you sadly.
I don't read the tabloids, a pig (as I understand it) is genetically different to a human, pig organs are not transplantable to humans (as I understand it), therefore (as I understand it) it would have to be genetically modified, this incurs a risk.
Namely pig borne viruses and diseases that do not affect humans, which if they mutate would not neccessarily have a known or effective cure.
I'll be blunt, I would be loathe to accept a valve from from a modified pig, and would prefer to face death, that's how highly I view the risk.
There are better ways of farming to solve the problems (we've plenty of food if only we'd share it), we've plenty of organs, if we assumed consent with an opt out.
These (to me) are better solutions, scientists (to my mind) should be more gainfully employed finding out new treatments for diseases or better pesticides etc, more money it and less investment too I'd wager.
A field is an odd place for labarotory conditions, perhaps that's why they dissent.