In those times , crusteans listed where and are scavengers , shiteaters as it were ,capable of making one very ill . In addition one can be born with a allergy to shellfish which is deadly , and it is not uncommon today for adults in midlife to develop the same deadly allergy .There were no drugs to save the victim back then.in addition there are shellfish that sting and kill rather quickly .
Pigs ? -trichinosis .Pigs eat their own swill .
The ole’ milk and meat ban came from a civilised attitude towards animals, as boiling a cow pregnant with calf , the unborn calf being the delicacy was a common practice .

There was sound reason and logic based on experience and observation , regarding the dietary laws , in the age in which they were written .
Today of course methods of preparation and medicine has changed all that , making it really unneccessary to abide those laws except for sake of tradition . To this day the most humane way to slaughter an animal is with an extremely sharp knife severing the caratid artery , it is painless and fast .
As for the gay thing , well we should all know better by now .