I personally do not recommend feeding pigs solely - they are very fatty and it isn't the best source of protein. Yes, it is meat and it is protein, but the quality of the protein isn't as great. I've heard that retics fed pigs only tend to run into lower fertility down the line, more females slugging out, etc. Also heard a lot about the stinky runny stool :ack:
I think feeding them occasionally, or right after a female lays is perfectly fine - I just wouldn't recommend feeding pigs every meal. Of course I have no double blind scientific studies to link ya to, sorry