The Coopworth breed of sheep was developed by a team of scientists at Lincoln College (now Lincoln University) in Canterbury, New Zealand, to increase lambing percentages of Romney ewes when mated with Border Leicester rams. The breed makes up the second-largest flock in New Zealand. It is also bred in Australia, parts of Europe, and the United States. The Coopworth is used for both meat and wool. An average fleece weighs 5 kg, with a fibre diameter of about 30 to 35 microns being in the coarser range of wools with a staple length of between 125 and 200 mm. The life weight of an adult is about 55 kg.

History

The first scientific study of the Border Leicester cross ewe was initiated in 1950 on the Ashley Dene property of Lincoln College. Further extensive investigations were carried out at the Whatawhata Hill Country Research Station, to be followed by an intensive study of interbreeding the Border Leicester x Romney at the Lincoln College Research Farm. The purpose behind these experiments was the realisation by research workers and some farmers at that time that the New Zealand lambing percentages were not high enough. Raising the percentage must be one of the prime objectives of sheep research in the future, and crossing existing breeds with the Border Leicester, which was known to be of high fertility, might offer at least one solution to the problem.

Experiments showed that the first cross ewe by the Border Leicester ram gave a lambing percentage which was 15–30% above that of the parent ewe breed. Favourable results raised the question of whether Border cross sheep and Border-Romney in particular, could be interbred to fix a stabilised pure breeding sheep having the desirable characteristics which the first cross sheep undoubtedly had.

The breeding policy at Lincoln was to select for fertility as the interbreeding went on and to make comparisons with the original F1 ewes and a Romney flock. The comparison suggested that there was a slight decline in fertility from the F1 to the F2 and F3, but there remained a very substantial advantage over the Romney. Meanwhile, some interested sheep breeders continued to interbreed and select very strongly for fertility. Although they had no control flock, their lambing percentages have shown no decline with interbreeding they claim that it has increased, and their percentage has remained very much higher than their neighbours’ or their district average. Encouraged by the results several flocks commenced selling interbred rams throughout New Zealand. The breeders concerned believed by the late 1960s that they had third generation (F3) sheep which were of high performance, retaining the desirable characteristics of the first-cross Border-Romney. A small meeting of those concerned called a general meeting of interested persons in November 1963, at which a Society was formed and after a vote on possible names, the name Coopworth was adopted. The New Zealand Coopworth Sheep Society controls the selection standards based on recorded performance standards.

Breed characteristics

Coopworth sheep are a medium-sized, dual-purpose, longwool breed, with an alert but quiet disposition. The long face is usually clean with a small topknot or bare head and a slightly Roman nose. They stand a bit taller than the NZ Romney and exhibit heavier muscling than the Border Leicester. The body is long with a good loin and hindquarter, light forequarter and a wide pelvis. The fleece, with pointed locks, has a well-defined crimp with bright lustre and spinning count of 44–48 (35–39 micrometres) and a staple length of 6–8 inches. While only white Coopworths may be registered in New Zealand and Australia, both white and natural coloured Coopworths are accepted for registration in the United States and Canada.

The ewes lamb easily and very few indeed have to be assisted as there is little or no bearing trouble. It is these characteristics that derive from the better shape of the pelvis of the ewe and the narrower head and shoulders of the lamb. While easy lambing is the main feature of easy-care, two other features are significant. Coopworths are open-faced and require no eye wigging. At shearing the points are clear but this makes for the extra weight of the ewes.

In addition, the Coopworth are excellent mothers. The Coopworth ewe has a highly developed mothering instinct and does not run off when disturbed. Its milk production is very good, all of which makes for easier lambing management, less labour, and a higher lamb survival rate despite a higher proportion of twins. It is the considered and conservative opinion of those who have Coopworths that the shepherding required at lambing is less than half of that required for Romneys and Corriedales. As an alternative to using less labour, hill county farmers are finding that they can shift Coopworth ewes and lambs at an early age without mismothering and so move into an intensive shepherding and shedding-off system on hill country.

Another feature is their ease of mustering especially in the broken or scrubby country. This may well result from their clear face and longer leg. A third feature is that as young sheep they grow rapidly, and present fewer difficulties in hogget rearing.

It is important to note that it is not unusual to see differences in appearance between individual animals because selection based on measured performance, rather than phenotype, has traditionally been the basis for registration. For this reason, several wool styles are considered acceptable. These would be similar to Border Leicester and NZ Romney wool types.