Great Britain has developed a unique way of producing prime lamb, a.k.a market lamb. The process is traditionally called a Three-tier
system. This Stratified or Three-tier breeding system has been perfected over hundreds of years in the United Kingdom. It works because
the breeds involved have been fine tuned to genetically mesh with each other during each step of the system.
It all starts at
the top with what is sometimes referred to as a “hill or upland sheep”. These hill and upland sheep are typically the local or endemic
breed to a given area or region that survives well in its environment. Examples of a few regional breeds are: Scottish Blackface inScotland,
Swaledale in Northern England, Welsh Mountain in Wales, and the Clun Forest in Shropshire.
These hill and upland ewes are then
bred to a Bluefaced Leicester ram to produce crossbred progeny referred to as “Mules”, Scotch Mules, North of England Mules, Welsh
Mules, Clun Mules, Cheviot Mules, and more recently from the lowlands the Dorset Mule. The Mule is the backbone of the UK’s prime
lamb production system. Fifty percent of all UK crossbred (commercial) ewes are Mules. These Mules inherit the vigor and hardiness
of its dam with the added benefit of an improved wool clip, increased body size and capacity, higher prolificy (some flocks exceed
200%), early maturity (it is common to breed the Mule ewe lamb in her first year) and milkiness from her Bluefaced Leicester sire.
Mule ewe lambs are either retained for the next step of the system, or sold off the farm in the fall at the livestock markets by the
thousands. They are purchased to make-up large commercial flocks for the UK’s “prime” lamb production. In the final tier of the scheme
the Mule ewes are bred to terminal sires, renowned for their heavy carcass genetics; the preferred ones being either a “British” Suffolk or
the Texel. This third step in the system produces a carcass lamb that easily reaches market weights off milk and grass.
in the States there has been an increased interest to replicate the UK’s 3-tier system. Breeders of hill and upland type ewes have
acquired Bluefaced Leicester rams for Mule ewe production. They then either market the Mule ewe lambs, or in some cases complete the
system by breeding the Mules to either a UK genetically improved Suffolk, or a Texel sire. This type of prime lamb is filling a growing
niche in the specialty trade to restaurants, internet and catalog orders, the ethnic market, and the ever growing demand by consumers
for wholesome, healthy, grass fed lamb.