Rocco Green Beef Tripe

My dog loves green tripe but refused to eat this one "Rocco" brand. Can't blame him as it smells awful, old unfresh odour. The expiry date is all right on the package but I suspect that product is unfresh. I also bought the same 'Rocco' make Beef Scalps Skins and it's same old odd smell. My dog doesn't want to eat it. A waste of money.