You probably didn't know many mink farmers from back in those times. Sounds like a good use of waste fish. I'm sure that the wild mink of that time never checked the "ash" content of the fish, like they do today.

Some of the research on PCB's came from ranch mink being fed PCB contaminated fish from the great lakes. Mink are very intolerant of even low levels of PCB's.

Alewife’s and salmon are short termed fish in that lake. Not many if at all pcbs were found it those species. Those biologist really put a bad rap on 90 percent of the Great Lakes fisheries

I worked on a mink ranch for 4 years when a young guy. Owners son and I were good friends, we used to fish lake Erie 2-3 days per week for walleye and smallmouth. As usual, we'd catch a ton of sheepshead and we'd fill up 5 gal pails with them to throw in the grinder for mink. Was always funny pulling back into the boat launch and guys would as how we did...we'd say great and show them the buckets of sheepshead and act proud...man we got some looks...and we never had a sick mink.

Mink food was made by mixing dry pellets along with many other ingredients. We did a weekly run to the slaughter houses and purchase tripe and other cattle organs in 55 gal drums, go the the chicken farms and buy vats of cockrels that were blast frozen, along with wings...this before wings were a thing, at .05 a lb. We'd go to the cheese factory that made ricotta and cottage cheese, buy all their stuff that was store date expired for a couple bucks per case. All this got ground up, water added until you had a nice pasty consistency, then transfer to the feed tractor that had an auger to push this paste through a tube. Drive down through the pens plopping a pile on top of each cage, the mink would pull it through the wire.

Was a lot of work taking care of 3000 mink, cleaning poop piles, feeding, breeding (where I always got bit a few times as you are handling mink), and then the skinning season, usually 3rd week in November. During skinning time we'd hire 4-5 trappers we knew of as they knew something about skinning.

There were more than a few mink ranches along Lake of the Woods that used the bycatch from commercial fishing on said lake. They are all gone now. Unfortunate!

I might add that cooking devalues the food source and many ranchers would pass because it had to be cooked. Mink nutrition is science. Pretty fascinating industry all around imo. It is unfortunate that it no longer fits in today’s world.

Ranch mink have one of the shortest digiestive systems of any mammal and thus need very easily digested protein and protein with high fat and extremely low fiber. There is a real science to feeding, breeding and raising mink and keeping records for breeding stock is a huge job when you are dealing with thousands of animals and tracking history etc. One of the huge losses when mink are released and the animals don't have chips or tags is losing all those years of breeding records.

Bryce