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.
The B+LNZ Genetics Central Progeny Test was launched in 2002 and helps sheep farmers identify the best genetics across sheep breeds, by comparing the performance of rams’ offspring under the same conditions. The test results provide vital information that underpins B+LNZ Genetics’ SIL-ACE (Advanced Central Evaluation) – the world’s largest across-flock, across-breed genetic evaluation.
There are three lowland sites – Poukawa (Hawke’s Bay), Ashley Dene (Canterbury) and Woodlands (Southland) – and two hill country sites – Onslow View (Central Otago) and Koromiko Station (Wairarapa).
The focus of the test was recently adjusted towards hill country, which is where most of New Zealand’s sheep flock are now farmed. Testing at Poukawa and Ashley Dene is being phased out. At the same time, however, testing on purely commercial farms will be introduced.
Traditionally, about 20 new rams have been 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 programme will increase the number of rams 4-5 fold.
Genetic merit is established by comparing the performance of offspring of different sires run together. Sires are chosen 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, based on 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 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.