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Merino:  King of Sheep

The Merino is the most important breed of sheep in the world. It is is estimated that fine-wooled sheep account for more than 50% of the world’s sheep population. You can’t visit Australia and New Zealand (which I recently did) and not expect to see a lot of Merino sheep.

The modern Merino was developed in Australia, and Australia has the most advanced wool industry in the world. Though declining in numbers, Merinos still comprise more than 50 percent of the Australian national flock. New South Wales is the main wool-producing state. Australia is the world’s largest exporter of wool. Most of their clip is destined for China (~65%), but the best quality fiber goes directly to the (high) fashion industry in Italy.

While only 10% of New Zealand’s sheep are Merino, they are the third largest exporter of Merino wool. New Zealand’s Merinos are raised in the High Country, the elevated pastoral lands of the Southern Alps. The Icebreaker® brand is based in New Zealand.


So, what’s so special about Merinos and their wool? Where do I begin? Merino sheep originated in Spain during the Middle Ages. Spain’s wealth was based on fine-wooled Merino sheep. Merinos were a protected resource, so valuable that it was a capital offense to export a single sheep. It wasn’t until Napoleon invaded Spain that the world gained widespread access to these incredible sheep.

The first Merinos were imported to the US (to Vermont) in 1802. By 1837, Vermont’s flock had grown to more than a million head. The flock peaked at 1.68 million in 1840, but collapsed soon thereafter, due to the boom-bust cycle of the wool market. A second wave of “Merino mania” struck in 1860 during the Civil War, as wool was needed for military uniforms. But, by this time, Vermont faced tough competition from sheep farms further west. Today, Vermont has fewer than 20,000 sheep.


As a sheep, Merinos are medium in size: ewes, 125-180 lbs.; rams, 175-235 lbs. Merino rams have long spiral horns that curve around their faces. Horn growth is suppressed in ewes and wethers. Poll Merinos are gaining in popularity. There is also a trend to make Merinos more of a dual-purpose (wool + meat) breed.  The breed is known for its longevity and strong flocking instinct. Merinos breed out-of-season, and there is speculation that the aseasonality of Dorset sheep is derived from the Merino, as Merinos inhabited Southern England at the same time the Dorset evolved.



High Country Merinos, New Zealand

Merino wool is the softness, finest in the world. Fine means the wool fibers have a small diameter, usually less than 22 microns. Superfine and ultrafine Merino wool is even finer, less than 15 microns. The finer the wool is the less likely it is to itch. Clothing made from Merino wool can be worn close to the skin, though even Merino wool varies in its “comfort factor” (a measurable trait). Yes, it is possible to buy Merino underwear!


While Merino sheep are still raised in the US, the Rambouillet is more popular. In many respects, it is the American version of the Merino, having been derived entirely from the Spanish Merino, via exports to France and Germany. Compared to the Merino, the Rambouillet is a larger, more dual-purpose sheep. Rambouillet wool is similar to Merino wool.


The Rambouillet is the most important commercial breed of sheep in the US. The Rambouillet and its crosses (Columbia, Targhee, Polypay) are suitable for many different production environments. Sometimes, Merinos are crossed with Rambouillets to improve wool quality.

This article was written in 02.14.17 by Susan Schoenian.

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