Dan, my friend James Parker requested domestic cow sinew for the Asiatic Horn Bows he builds. I really think sinew is sinew, some is longer than others, some seperated better than others, some are greasier than others but sinew is sinew. d;^)
I really like how this cow sinew is to work with. I got it already shreaded and clean so I don't know what it takes to get to that point but as far as working with it it is up there with any other I've used.