Q: I love game meats, and many of them are better for you than beef and pork. So I’m curious why so few Texas pitmasters are doing bison ribs, venison sausage, elk roasts, and chicken-fried duck. Greg Day, LakewayA: The foundation of real-deal barbecue, as any carnivore worth his or her salty rub can tell you, is the tasty triumvirate known as the Texas trinity, i.e., beef brisket, pork ribs, and sausage. Barbecue menus will, of course, also often feature chicken, turkey, pork butt, perhaps some pulled pork, and maybe a smoked pork belly, prime rib, or thick-cut pork-chop special. That’s just how it is here in Texas, Mr. Day. But why, you have asked, does the classic three-meat plate prevail when we could avail ourselves of…