This really has to do with Eastman in Rochester, but the key fob and key ring were found at a flea here, so let’s check it out.
The patent office shows that Eastman was granted a patent for this ISO Plus Nutritional Supplement, apparently for those of the bovine persuasion, in 1983, the first known date for the commercial use of this product. As of 1992, however, the patent is shown as “Continued use not filed within grace period, un-revivable”.
Perhaps it just didn’t work out.
Bob Lawrence's Kingsport 
I was in the animal nutrition business when this product was released. According to the stories told at the time, the basic ingredients were by-products of manufacturing something else but some researcher in dairy nutrition showed that if you could get cows to eat it, they would produce more milk up to 5 lbs. more per day on average. A dairyman getting $12/cwt. could increase income by about 60 cents per cow per day for a cost of about 25 cents per cow per day. Of course the price of production for Eastman was essentially nil plus packaging and marketing. It wasn’t very successful – it smelled like puke so getting cows to eat it was a problem. And about that time, Monsanto started selling Posilac (rDNA Bovine Growth Hormone) which was more effective and Iso-Plus disappeared.
Thank you for the information! It’s a highly competitive market out there and if you have trouble even getting cows to eat your product, well…