I'm sorry Beleg813 but that is not correct. There was a test done in Europe a few years ago and they found that Cow sinew was the best, I have to say I disagree though. Some Horn bowyers use Moose sinew for their hornbows and I prefer it to Deer but mainly because of its length not because it is "better". I have used Deer, Moose, Cow and Ostrich sinew in very high stress bows and all have worked equally well, Ostrich sinew is weird stuff though. I have also mixed sinews, in some cases having a mix of 3 different ones, with as good a result as just using one type. It really doesn't matter what kind of sinew you use as long as it's applied properly and used to its full potential.