Coopworth Genetics (formerly Sheep Society) of New Zealand


The name of the Society is "Coopworth Genetics of New Zealand" (formerly "The Coopworth Sheep Society of New Zealand").


The Registered Office of the Society shall be at the address of the Secretary from time to time or such other place as may from time to time be decided by the Council.

Technical Secretary C.M. Logan
P.O.Box 169
Lincoln University
Ph: 03 3252811      Fax: 03 3253851
Web page:


The objects for which the Society is established are -

  1. To promote and encourage by emphasis on the measurement and recording of productive characters the breeding of sheep most profitable in terms of both meat and wool.
  2. To accept for registration such sheep as shall from time to time meet the breeding standards of the Society.
  3. To draw up regulations to control breeding selection and culling designed to promote and encourage the objectives of high lambing percentages, long productive life, high growth rates, good weight and quality of wool and easy shepherding in the breed.
  4. To promote the continued improvement of the breed.
  5. To establish and publish a Flock Book of the Society listing with details, the registered flocks and such other information as the Council may from time to time decide.
  6. To appoint Inspectors to examine members' sheep and records and to recommend flocks for registration or otherwise.
  7. To collect subscriptions, fees or charges, accept gifts, invest and borrow money with or without security, provide facilities for the conduct of the Society's business, arrange exhibitions, arrange extension and publicity activities, to employ and dismiss staff and perform and carry on all such other lawful acts and things which are deemed conducive to the attainment of the objectives of the Society.
  8. To engage in or subsidise any branch of scientific research to further the productivity and profitability of sheep fanning.
  9. To investigate the use of any genetic material which may be available and to form associated Flock Books incorporating this material if in the opinion of the Council of the day this action would be of national benefit.


The Coopworth breed had its origins in the 1950's and 1960's in the crossing of the Romney ewe with the Border Leicester ram to produce the F1 Border-Romney and the subsequent inter-breeding of them to give F2 and F3 generation progeny, which were then eligible to be known and registered as Coopworths.

Since the 1970's the base of the Coopworth breed has been widened to include sheep bred from white faced breeds other than the Romney, by continued topcrossing with Coopworth rams.

Definition of a Coopworth

The present recommended breeding programme to produce a Coopworth, is two (2) topcrossings by Coopworth Single Entered (S.E.) rams over any other white faced wool breed or wool breed cross ewe. Alternatively registered or screened Coopworth ewes may be mated to any other white faced white wooled ram to produce F1 female stock that then must be mated to a Single Entry Coopworth sire to produce eligible foundation stock under sub section 3 following.

Coopworth Definition

F2 Ewes and F3 Rams are acceptable for entry to Registered Flocks.

Eligibility for Registration

  1. The foundation stock may be either registered (pedigree) or commercial. The Regulations require that the sheep presented for registration shall have come from foundation stock with a good breeding history and have already been subjected to a high degree of selection based on recorded measurements. The breeder shall currently be recording on a Society approved performance recording scheme and applying Ewe and Sire Summary and selection List data to a progressive breeding policy.
  2. Sheep presented for inspection and registration must be within DEFINITION (2). They must also have been recorded on a Society approved scheme for a minimum of one lambing, or be the progeny of parents recorded on the scheme, i.e. accompanied by a Two Tooth Selection List. Minimum acceptable performance requirement will be that a ewe has reared a reasonable set of twins or have positive Index for maiden ewes on a Two Tooth Selection List.
  3. The degree of eligibility may vary according to the known breeding history of the foundation stock and the degree of selectivity applied. Sheep submitted for inspection for registration shall represent the top 20% of their age group based on a recorded performance of fertility, growth rate, fleece weight and be physically sound, growing quality wool and be acceptable representatives of the breed.
  4. Stock into which the Booroola "B" gene has been introduced, are not acceptable for registration.
  5. All flocks must hold current Brucella Ovis accreditation.
  6. Council may from time to time progressively raise the standards required for the registration of new flocks originating from Definition 2.

3:1 Composite Breed Flocks

The Society will recognise, inspect and separately accept under the title of Composite Breed Flocks, sheep falling outside Definition of a Coopworth, Section II.

Flocks applying for entry to the Composite Breed Flocks section must have applied Coopworth Society regulations specifically 4 to 11 following, for a minimum period of 3 years

To retain registration as a composite breed flock, subsequent generations must be maintained:

  1. Subject to Coopworth Society performance and selection requirements.
  2. Be White faced-white wooled.

Deregistration of Ewes

In order to improve early conception, lambing percentage, lamb growth rate and wool weight and quality, the following sheep shall be deregistered, their ear tags removed and positive identification applied.

  1. Any ewe (other than a hogget) which is barren.
  2. Any ewe which on more than one occasion fails to lamb in the first 38 days.
  3. Any ewe which does not rear a set of her own twins at or before her four tooth lambing.
  4. Any ewe which does not lamb naturally, has a faulty udder, or has bearing trouble.
  5. Any ewe which prematurely develops poor wool or loses constitution, or develops foot faults or defects.
  6. Any two tooth ewe which does not rank in the top 75% of latest selection list based on NLW.

Inclusive of the above, the culling at the hogget stage and after the two tooth lambing shall be such that 40% of that age group must be culled between weaning as ewe lambs and mating as four tooths.

Flock Prefix

Flock owners are required to submit to the Council for approval and registration, a prefix for their flock. The Registered prefix shall be reserved for the use of the flock owner and shall be used for all sheep born in his flock. The purchaser of a registered flock shall have no right to the previous owners prefix or flock number without his written consent and the approval of the Council.

Deregistration of Flock

The Council reserves the right to inspect any flock and the records kept, and a whole flock can be deregistered if in the opinion of the Council, on the advice of any three inspectors, the standard of the flock, recording, or any acts prejudicial to the breed, make the flock unacceptable to the Council, or if the rules and regulations of the Society are not being carried out both in spirit or in letter.

Every year a number of flocks will be balloted by Council and subjected to an inspection of records and/or sheep. The owner of flocks not meeting Society requirements, may receive assistance and guidance from Council. If Society requirements are not met the flock may be deregistered at any time.

Eligibility for Single Entry Rams

AH rams and ram lambs mated in Registered Flocks must be Single Entered. To qualify for Single Entry a Ram must:

  1. Be at least F3 and be born in a registered flock.
  2. Be in the top 25% of Index (based on NLW) as shown on the most recent Selection List (Flock Summary - Rams).
  3. Rams for Transfer or use under Certificate of Service must be inspected. Rams for "home" use are not required to be inspected.
  4. Rams whose teeth are not fully erupted may be passed by Inspectors, providing this is noted on the S.E. Ram Card.
  5. All Single Entered Rams and Ram Lambs used or sold must be accompanied by a Single Entered Ram Form, signed by the Breeder and countersigned by an Inspector in the case of a ram subject to Transfer. The SE card must be fully completed and show all required information as presented by a Society approved performance recording scheme.
  6. Be from a ewe which will not be deregistered under Rule 4.

Society Standard REVs:

SIL Dual Purpose Overall (* DPO) = SIL Dual Purpose Growth (with Meat) + SIL Dual Purpose Meat (with Growth) + SIL Dual Purpose Reproduction + SIL Dual Purpose
Survival + SIL Dual Purpose Wool
SIL Dual Purpose Growth (with Meat) (* DPGM) = 36 * WWTBV + 106 * CVJBV - 10 * EWTBVV
SIL Dual Purpose Meat (with Growth) (* DPMG) = 1 58 * LLANBV - 132 * FATBV
SIL Dual Purpose Reproduction (* DPR) = 1720 * NLBBV
SIL Dual Purpose Survival (* DPS) = 3400 * SURBV
SIL Dual Purpose Wool (* DPW) = 126 * FW 12BV + 378 * LFWBV + 350 * EFWBV
CW13V = carcass weight BV; EFWBV = ewe fleece weight BV; EWTBV = ewe live weight BV; FATBV = fat weight BV; FW12BV = fleece weight 12 BV; LEANBV = lean weight BV; LFWBV = lamb fleece weight BV; LWBBV = live weight 8 BV; NLBBV = number of lambs born BV; SUR

N.B. When presenting Rams for Single Entry registrations, the most recent fertility record of the Dam must be included in the assessment of fertility. Dots over fertility records indicate that one or more of the lambs born in a particular year was not reared to weaning. Should the ewe have died or been removed from the flock that fact must be indicated by an X.

Certificate of Service

The owner of any ewes mated with registered rams not his own, must return to the Secretary, the Society's Certificate of Service signed by the owner of the rams.

Flock Book

A Flock Book shall be published annually giving a list of all flock owners and all rams Single Entered. For every flock a history will be given, also listed will be the number of ewes mated, number of ewe and ram lambs weaned the previous season, the prefix and eartag numbers of Single Entered sires used.

Presentation of Sheep for Sale

Sheep offered for sale may be dipped, (not bloom dipped, covered, trimmed, locked, oiled, plucked, singed or washed), but otherwise wool must be in natural condition.

Ram hoggets, including potential Single Entry, shall in the North Island not be shorn before 20 June, and shall in the South Island not be shorn before 20 July, nor any ram hogget be grazed preferentially until after last hogget input.

Purchasers of ALL rams or ram hoggets must receive a Society performance card, showing Index and all required BVs. Rams sold at Auction must have cards displayed on the pens, unless a catalogue adequately covering the Society requirements is available.

ALL sheep offered for sale shall be accompanied by performance information.

Single Entry rams failing Society inspections or adjudicated against at auction sales will not be eligible for transfer, except that rams injured or unwell on the day may be subsequently inspected.

The Society reserves the right to remove a sample of wool for microscopic examination to detect practices contrary to Society Regulations.


Registered sheep offered for transfer must pass inspection within the three months prior to leaving the vendor's property. Pedigree and Transfer Forms must be signed by the vendor and the purchaser. Transfer Forms to be forwarded to the Secretary before closing date for Flock Returns.

Two tooth ewes sold for transfer must be in the top 75% of latest selection list based or No of Lambs Weaned (NLW).

Sheep inspected for transfer and rejected shall no longer retain registration in the breeder's flock.

Following purchase, further transfers will not be permitted within twelve months, without prior consent of Council. Females purchased by other than a registered or intentions.

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