B+LNZ Genetics operates both a sheep and a beef progeny test. The Central Progeny Test is a long-standing and critical component of New Zealand’s sheep genetics system, while the beef progeny test was launched in 2014.
A progeny test is used to benchmark the performance of a ram by comparing how his progeny perform relative to progeny from other rams in the same environment. In this way, rams can be compared across different flocks.
B+LNZ Genetics Central Progeny Test (CPT) currently involves 180 rams, across nine sites (including six commercial properties and three cadet-training bases).
The benchmarks created by this test underpin NZGE – the weekly large-scale across-flock and across-breed evaluation.
The B+LNZ Genetics CPT was launched in 2002 and ran across three lowland sites.
In 2013, the test added a comparison of performance on two hill sites, compared to the existing lowland sites. The same year, it also added a “genetics by environment” element, by testing the rams’ progeny generated in different environments in the same year. Progeny were produced through AI, with reference rams used between years and between sites to provide benchmarks for ranking rams.
In 2016, the test’s focus was adjusted further towards more commercial hill country environments (where most of New Zealand’s sheep flock are now farmed) and – in partnership with industry – “Next Generation” flocks were introduced.
These 2016 changes allowed:
Hub sites focus on flock connectedness between the Next Generation flocks. This connectedness underpins across-industry genetic evaluation. Hub flocks also provide a resource for add-on innovative projects.
Next Generation sites build stronger connections with ram breeding flocks in the industry. Each Next Generation site focuses on either a breed type or specialist challenge relevant to the land type and geographical location.
Next Generation sites
Horizon Farming’s Maraetotara block, Hawke’s Bay
- Focus on terminal breeds
- Partnership with Progressive Meats Ltd.
Smedley Station, Hawke’s Bay
- Focus on maternal traits in hill country environment
- Partnership with Perendale Society – room for other breeds, in future.
- Focus on terminal breeds and genomic calibration for meat traits
- Partnership with Silver Fern Farms.
- Focus on best practice use of existing genomic and RamGuardTM tools to identify rams that
produce FE-tolerant progeny
- Innovative use of ewe hoggets as dams, so prior use of submitted rams at the home stud farm can
occur for best practice connectedness
- Partnership with FE breeders.
- Focus on connectedness for Southdown breed and meat quality
- Partnership with Southdown Sheep Society
Traditionally, about 20 new rams were tested, with lists published annually of the top 25 rams for each of several meat (terminal) and dual-purpose (maternal) production traits. Once fully implemented, the 2016 changes will increase the number of rams tested by seven-fold.
Genetic merit is established by comparing the performance of offspring of different sires run together. Sires are chosen for entry firstly on the basis of high genetic merit, then on how they help flock connectedness across the industry.
The test compares the lambs of terminal rams using a growth index, which considers the genetic merit for weaning and carcass weight, and a meat value index, derived using VIAscan predictions of the meat in the loin, leg and shoulder provided by Alliance Group Ltd. It is likely this will be expanded to include use of commercial carcass value from other meat companies. Lambs of maternal rams will be compared across a range of production traits focused on the lamb and the ewe, together with important health traits.
The B+LNZ Genetics Beef Progeny Test compare bulls under New Zealand commercial farming conditions. The test is being run over two years and involves about 2200 cows and heifers on five large properties across New Zealand.
A mix of both internationally-sourced and New Zealand semen is being used. Steers and cull heifers will be assessed on their carcase traits, while replacement heifers will be tracked for their maternal characteristics.
Alongside the core Beef Progeny Test, a four-year dairy-beef test is being carried out at Limestone Downs. Its goal is to calculate the additional value that can be added by using high-genetic-merit beef bulls, versus the unrecorded bulls traditionally used as “follow-on bulls” in most New Zealand dairy systems.