Categorizing sheep breeds in a useful manner is always a bit of a dilemma as sheep are such versatile animals who provide a lot of value for the worth we currently place on them.
Human opinion must also be accounted for and what you read here is merely that. You are the best judge of your goal and your place, always go with what your intuition is telling you will work for you, and with what will suit your needs, which will be as individualized as the sheep you buy.
Let's start by deciphering what animal characteristics lend themselves well to raising sheep on grass.
Hardiness - able to maintain good body condition on grass and hay feed, do not need supplemental feed rations and grains in order to maintain flesh and stay healthy. Providing supplemental feeds to these animals will be an option during times of adverse conditions or stress, not a necessity.
Efficient on feed - they eat and maintain condition versus eating to become obese
Lamb without assistance - their good physical condition leads to birthing ease and lambs with good vigor (get up and go). The ewes have good maternal skills, they know which lamb is theirs, are possessive of those lambs, tend to them and mother up quickly.
Raise a lamb on grass - the ewes are very capable of producing enough milk and raising their lambs without requiring supplemental feeds. The lambs grow well, begin to nibble grass early on and thrive on pasture as well.
Survival - will scent out water, will take themselves to shelter when ugly weather moves in, will be alert to the surroundings
Columbia, Rambouilett, Targhee, Katahdin, Clun Forest, North Country Cheviot, Corriedale
There is a reason that many of the sheep breeds noted as being good for grass based production also possess strong maternal traits. Animals with strong maternal traits are a very important facet of this style of management.
Columbia, Merino, Dorset, Polypay, Rambouillet, Targhee, Clun Forest, Corriedales
The maternal breeds will express characteristics such as strong bond
to lambs, will keep track of their lambs and keep them close by, lamb
easy, attend to newborn lamb immediately, good milkers (but not heavy
milkers necessarily), raise lambs with vigour.
It's probably fair to say that most fanciers of a breed of sheep will tell that their ewes are good mothers since a truly poor mother is no good in any style of management. However, it's also fair to say that ewes who lamb in jugs (small pens) are not really being tested for natural mothering ability.
Charlollais, Canadian Arcott, Hampshire, Suffolk, Texel, North Country Cheviot
These sheep breeds are noted for their beefier frames, carcass qualities and good rate of weight gain. Terminal sire animals are often used for the purpose of producing a market lamb. The female offspring from terminal sires are not usually kept on as replacement ewes as the qualities sought for replacement breeding animals are not those expressed by terminal sires.
If you are in the early
stages of building your flock you may wish to build up your maternal
qualities to grow the foundation of your ewe flock and then focus on
terminal sires for producing market animals.
You also have the option of splitting the flock and using different rams for the two purposes. You would place a ram of the maternal breeds with your best maternal ewes and keep the best replacements from this group. For the second group you would select a terminal sire breed for a ram and then market all the resulting offspring from this group.
our own flock we put emphasis on raising ewes. The ewes are who and
what we raise, they are who we work with day in and day out, and their
characteristics and qualities make our work easy or difficult. The lambs
are the offspring of the ewes, and/or a food product. It is our gut
feeling that if we place emphasis on maintaining healthy maternal ewes
of moderate but solid stature and frame size, the market lamb
characteristics will be there year after year, plus the continuation of
those good ewe qualities will continue with little work from us.
Our ewe flock is North Country Cheviot X Clun Forest. We also have a handful of purebred Corriedale ewes. In our ram flock are purebred Clun Forest rams, cross bred Clun Forest / North Country Cheviot rams and purebred Corriedales.
Storey's Illustrated Breed Guide to Sheep, Goats, Cattle and Pigs written by Carol Ekarius.
A great book of photos and quick facts about numerous breeds of livestock.