The Journal of the American Oil Chemists Society, 1965, (Vol. 42, page 540) and in Lipid Metabolism of Animals Journal, 1977
100 grams of raw hog or cattle testicles contain the following: 3 grams fat, 375 mg cholesterol, 26 grams protein, 1 gram carbohydrate and 135 calories.
Certainly the other guts and offal in animals are very nutritious, I see no reason why testicles would be any different. Sweetbreads, liver, kidneys, stomach, stomach lining, and hearts and gizzards are all pretty common these days. What else would you use to make thanksgiving gravy, if not the giblets?
Sausages are often bound in cleaned intestines, the "caseless" sausage is a recent invention. Brain tacos are a favorite of mine from good taquerias, and one has not lived until they have consumed a fiery hot bowl of freshly made menudo, laden with ribbons of tripe. Tete au veau is a whole calves face, braised until mouthwateringly tender, and the best part about Pho soup is the stuff that they don't sell in the mouldering refrigerator at safeway. I'd imagine that cock's comb is a lot like chicken feet - something that always perks me up when I am out for dim sum.
seems to me like the richer and more wasteful we become, the more we move towards homogenized, pre-packaged, frozen otrocities that may or may not have come from an actual farm. I think a slaughter-to-the-table experience is a really good one too - and proves that nothing is more delicious than a meal that you really understand.
sorry for the rant, i'm getting hungry and all this talk about food makes me want to talk more about food :-) Besides, I'm a professional chef so food is something I'm known to get a little passionate about.