The Coopworth Breed
The Coopworth is a new breed of sheep developed from crossing the Border Leicester and the Romney and then interbreeding the progeny of this cross.
There are accounts of Border Leicesters having been used for crossing in the early days of the sheep industry but there is little recorded information about their virtues.
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 percent 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 purebreeding 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 sheepbreeders continued to interbreed and select very strongly for fertility. Although they had no control flock, their lambing percentages have shown no decline with interbreeding, in fact 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 a number of 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 characteristicss 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 effect of higher growth rates is that drafting percentages are not lowered by the increased number of twins. If higher lambing percentages are not accompanied by increased lamb growth rate the percentage of fats goes down and of stores goes up. This does not happen with the Coopworth.
Another advantage derived from this higher fertility and growth rate is that the ewe hoggets may be mated in circumstances where other breeds would not. Where 40-50 per cent of Romney ewe hoggets can be got in lamb in May, 70 per cent or more of Coopworths can and this difference makes the mating of hoggets doubtful in the one and worthwhile in the other.
The ewes lamb easily. Very few indeed have to be assisted. There is little or no bearing trouble. These characteristics probably derive from the better shape of the pelvis of the ewe and the narrower head and shoulders of the lamb.
In addition, the Coopworth is also an excellent mother. It has a highly developed mothering instinct and does not run off when disturbed. Its milk production is very good. All of these attributes mean easier lambing management, much less labour, and a higher lamb survival in spite of a higher proportion of twins and these differences are not noticeable in the younger ewes. 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 mis-mothering and so move into an intensive shepherding and shedding-off system on hill country.
While easy lambing is the main feature of easy-care, two other features are significant. Coopworths are open faced and require no eyewigging. At shearing the points are clear but against this shearer's comment on the extra weight of the ewes.
Another feature is their ease of mustering especially on 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.
Use of Records
Deregistration of Ewes
Culling at the hogget stage and after the two tooth lambing shall be such that 40 per cent of any age group must be culled between weaning as ewe lambs and mating as four tooths.
Single Entry Rams
Records of Use to the Owners of Flock Ewes
Date of document unknown
Rose M. Woodsmall September 13, 2003
For more information, see
Jim and Martha McGrath
178 Lough Rd.
Franklin, WV, 26807