Central Progeny Test

central progeny test

The Beef + Lamb New Zealand Central Progeny Test helps sheep farmers identify the best genetics across sheep breeds. For farmers, this means valuable information for informing breeding stock selection.

The Central Progeny Test provides vital genetic connections that broaden the world's largest across-flock, across-breed genetic evaluation service – SIL-Advanced Central Evaluation.

Our service helps ram buyers identify the source of superior rams for the traits they want, regardless of breed or flock of origin.

Identifying new traits

The test also provides information on new traits to increase industry awareness of breeding values like meat yield and eating quality.

The wide range of breeding groups represented makes the test a valuable resource for projects that scan for traits that may be of interest in the future, such as low methane-producing sheep.

Central Progeny Test Results 2014-15 (PDF, 1MB)


The B+LNZ Central Progeny Test was established in 2002. Tests were originally undertaken at three lowland sites: Poukawa in Hawke's Bay, Woodlands in Southland, and Ashley Dene in Canterbury. Now two new hill country sites have been added to the programme: Koromiko Station in the Wairarapa and Onslow View in Central Otago.

Each year about 20 new rams are tested. Lists published annually record the top 25 rams for each of several meat and dual purpose production traits (breeding values).

Identifying genetic merit

Genetic merit is established by comparing the performance of the offspring of the chosen sires under the same conditions. Most rams are tested at one site with link sires tested at three sites across several years, allowing comparisons of rams across all sites and years.

The sires are chosen to provide connections to flocks in breeding groups that aren’t well connected in industry flocks. In this way, the test provides connections between flocks, strains and breeds that are not normally bred together.

The test compares the lambs of terminal rams using a growth index (calculated from weaning and carcass weight breeding values) and a meat value index (derived using VIAscan predictions of the meat in the loin, leg and shoulder provided by Alliance Group Ltd).

Breeding values

A number of breeding values are produced, including weaning weight and eye muscle area. Some meat quality measurements (pH and colour) are also studied to monitor the effect of selecting rams for growth and meat production on these traits.

Lambs of dual purpose rams are also compared using the meat value index. Some ewe lambs are retained for breeding and measurement of breeding values for the number of lambs born, fleece weight, worm faecal egg count and facial eczema resistance.