The Australian rural landscape is uniquely suited to sheep, with our relatively mild climate extending over vast areas of natural grassland. The Australian sheep flock is the world's biggest. Apart from its size, the outstanding feature of the Australian sheep flock is the overwhelming influence feature of a single breed - The Australian Merino - which is grazed primarily for its heavy fleece of fine quality wool. Almost 70 percent of all Australian sheep are pure Merino with most of the remainder at least part Merino blood.

Though the Australian Merino derives its name and basic appearance from the famed Royal Flocks of Spain, it is in every way a distinct breed in its own right, developed and adapted to the specific conditions in Australia.

Australian Merino is not a single homogenous breed but a number of "strains" of sheep. The four basic strains are:

• PEPPIN
• SOUTH AUSTRALIAN
• SAXON
• SPANISH

Most popular cross breed of sheep in Australia is the "Border Merino" Crossbred and comprises the ewe progeny from Border Leicester rams mated to Merinos ewes. The vast majority of Australian lambs slaughtered for meat are from "Border/Merino" ewes mated "Downs" breed rams (e.g. Poll Dorset or Southdown).

A number of breeds have been developed and "fixed" genetically by breeders in Australia and New Zealand. Foremost of these are the Corriedale and Polwarth, though the Perendale, Tukidale and Drysdale are also important.

This breed was produced by crossing the Lincoln and Merino and then carefully selecting the progeny to fix a desirable type. The Corriedale was developed simultaneously in New Zealand and Australia and it is now one of the world's most successful dual purpose (wool and meat) breeds.

This breed was developed in Victoria, by starting with a Lincoln/Merino first cross and then crossing back to the Merino again. Some Polwarths are to be found in New Zealand and South America but they are principally confined to Southern Australia and in particular Tasmania and Victoria.
While Corriedale thrives in diversity of climates - on saltbush country or highly improved pastures, Polwarth are mainly raised in higher rainfall areas where it is more tolerant of prolonged periods of wet weather than Merino.
 

There are a large number of breeds which came to Australia from England and are used primarily in the production of sheep meats.
The commercially important amoung these breeds are:
 

• Border Leicester
• Southdown
• Romney
• Dorsethorn
• Poll Dorset

A number of other breeds are found in Australia but at present are of little commercial importance. These breeds are:

Longwools:

• Lincoln
• Cheviot
• English Leicester

Shortwools:

• Shorpshire
• Suffolk
• Ryeland
• South Suffolk
• Hampshire Down
• Wiltshire