|
THE ORIGIN OF
THE COOPWORTH BREED OF SHEEP The Coopworth breed was developed in New Zealand in the 1950's and 1960's by Professor I.E. Coop at Lincoln University. He wanted to produce a sheep that used grass more efficiently and was more productive than the Romney. He chose the Border Leicester as the cross due to its higher fertility rate and superior mothering instinct. Since Romney sheep were the numerically superior breed in New Zealand at the time, he crossed Border Leicester rams onto Romney ewes. From the original cross he bred F1 to F1, F2 to F2, etc. Submitted by:
Marcia Adams |
Professor Coop found that the initial gains in fertility,
live weight and fleece weight that one could expect as a result
of hybrid vigor were lost in subsequent interbreeding. This loss,
however, could be overcome by careful and analytical selection
so that the following generations could actually exceed the original
F1 in performance. Rams were selected on the basis of their dam's
lambing performance including number of lambs born and weaned and
mothering ability. The rams were also above average in fleece weight
and grade. Ewe lambs were culled initially on the basis of their
wool production, but subsequent culling was based entirely on
reproductive performance. Thus, through careful analytical selection
for performance, the interbred sheep became superior to the foundation
breeds and became known as the "Coopworth".
In the United States today, the Coopworth Sheep Society of
NA promotes breed standards designed to maintain and improve
upon the integrity of the breed started by Professor Coop. Only
25% of a flock's top ram lambs may be registered in a single year.
Every registered ram must come from a multiple birth and be conceived
within the first 21 days of the dam's exposure to the sire. He
must be of above average growth and free of any physical defects.
The Coopworth ewe has been selected for her ability to produce multiple
births and for her ability to birth and raise her lambs with minimum
assistance. Only 70% of a flock's top ewe lambs can be registered.
Any ewe or ram that fails to produce up to the breed standards
is deregistered. Non-registered purebred sheep are known as commercial
Coopworths.
Because the Coopworth breed is a performance-based sheep the
Coopworth Sheep Society does not sanction competitive showing
of registered animals that select winners on the basis of appearance.
The Coopworth sheep represents years of careful selection and
culling based on measurable performance. Today, breeders continue
to strive for a productive, easily managed sheep to utilize forage
for the most economical growth.