Trenchers and the trencher fed.
Trenchers were, for want of a better description, a kind of medieval "paper plate," and the uneaten bits of the trencher (along with gravy, grease, kitchen scraps, and unusable offal) were tossed out to the dogs to finish off.
In the "good old days," bones were boiled white for soup, hides were tanned, fat was turned into soap and lard, and every bit of the cow and pig was used, from intestines (sausage casings) and blood (pudding), to tails (soup), and brains (fried in butter).
Unidentified bits and pieces like snouts, udders and shin meat became sausage -- sold as bangers in one country, and shnitzels in another, and choritzos in a third.
The idea that dogs were commonly fed slabs of pure beef or uncooked poultry wings is a modern fantasy.
At best dogs were fed kitchens scraps, and these scraps were often heavy with salt and smoke (the most common preservatives prior to the advent of refrigeration), and therefore not particularly healthy.
The term "trencher fed," is often used in 19th Century literature to refer to the old hound management system in which hounds (and sometimes terriers) were kept by individual farmers at their home and then brought to a meet to form a pack with other hounds on a hunting day.
A "trencher fed pack," then, was a pack of dogs assembled on the day of the fox meet, and raised on a catch-as-catch-can diet of table scraps and kitchen waste.
Today, the most common food problem a dog is likely to face is that it is very likely to be overfed and given too many vitamins.
Modern foods are often calcium-rich and vitamin packed. The result, especially in large dogs, is very rapid growth which can exacerbate pre-existing tendencies to dysplasia.
Is the "natural" diet of the dog prime beef and chicken?
As I note in a previous post, entitled Feed Me Like a Wolf,
The preferred diet of the wolf is not cooked backstrap from the pride of the herd, but raw flesh ripped from the diseased rectum of a downer cow.
You want to know what the "natural diet" of a dog is?
It's garbage -- what Pariah dogs are eating right now, the world over.
My point is NOT to say anyone should be feeding their dog garbage or table scraps heavy with salt and smoke.
It IS to say that almost ANY bagged dog food sold in America today is going to be more nutritious and less toxic to dogs than what was fed "in the good old day."
As always, feed what you want and what your dog seems to thrive on. The said, the key to good canine health is weight control and excercise. With about 40 percent of all U.S. dogs obese, and about 80 percent having poor muscle tone, my default advice is always less food and more exercise.