Utility fowl: Egg laying, meat and dual purpose categories. Utility = useful and there are becoming less and less useful pure breed hens due to indiscriminate mating. Too many people can't tell you whether they've got the utility strain of a breed and there is a lot of crossing of show and utility which greatly reduces the utility value of the offspring.
Orpingtons which were once a fine old utility breed have been bred for size, shape and fluff for so long that their utility value has been lost.
The only Wyandottes that remain under the utility banner are the utility Whites.
Other utility strains exist in:
Leghorns, White, Brown and Black
Sussex, Light, Buff and White
Marans, Copper Tone and French
Barred Plymoth Rock
Welsummer, Standard and Silver Duckwing
There is even a utility strain of Ancona Bantams.
Some of the Rare Breeds had a fine utility history but the rarer a breed becomes, loss of stamina, loss of a large gene pool makes the utility value very poor in most cases. Eventually the breed is kept purely for it's rarity value.
The Sussex breed bred for many years as a dual purpose bird has lost much of it's meat producing qualities except for a very few strains which continue.
If you are willing to go that extra mile for your poultry - make sure you're going in the right direction !