He looked at it the items on her plate thinking about it.  He'd had various kinds of sausage but figured most were pork.  "It's often pork, but could be beef or poultry."  He replied trying to remember what the cooks put in when they made sausages when he would bug them in the kitchen when he was a kid.  Along with salt, spices and other flavourings. Other ingredients such as grains or breadcrumbs may be included as fillers or extenders.  In the winter he could be a bother back then, but they had not seemed to mind as long as he didn't make a mess.  He was the son of the Earl after all.