Genetic find helps herds
Anovel scientific approach that’s pinpointed several genetic variants affecting New Zealand dairy cows has been published in scientific journal Nature Genetics. Scientists from LIC have leveraged the herd improvement co-op’s extensive animal database to identify genes responsible for major losses in production, some of which were found to be due to previously unknown genetic disorders in dairy cows. The newly discovered genetic variants impact animal health and milk production to the tune of up to $10 million in lost production each year across the national dairy herd. LIC chief scientist Richard Spelman says the finds reinforce the importance of continued investment in gene discovery and genetic analysis technology to help farmers breed healthier, more efficient dairy herds. “By supporting farmers to identify and minimise the number of animals that are susceptible to particular ‘negative’ genes, we can breed cows that are more resilient, speed up the rate of genetic gain and help ensure the sustainability of New Zealand’s pastoral industries for years to come.” From spring this year, all farmers using LIC’S Genemark DNA parentage testing service will have their calves screened for six genetic variants that have a significant impact on animal health and milk production and be notified if any of them are affected. This information will be provided free of charge alongside parentage results so farmers can make an informed decision on whether to retain these animals in their herd. Although affected animals are rare, about 0.5 per cent of calves born will be affected by one of these variants. Spelman highlights the value this knowledge will deliver to farmers. The “simple, convenient service” for farmer shareholders could save millions in lost production, he said. “Knowing what calves have these genetic variations will help ensure farmers rear only the healthiest, highest performing animals.” Traditionally the discovery of variants that cause genetic disorders has relied on farmers notifying LIC of affected animals before scientists can try to find the cause. Spelman says LIC is now able to take a more proactive approach which will allow them to discover rare disorders that might not have obvious physical signs. “Our approach starts with identifying significant drops in milk production or liveweight which may give a clue the animal is impacted by some underlying genetic disorder. If further investigation confirms this is the case, we can leverage diagnostic tests to manage the variant frequency.” Spelman says Nature Genetics’ publication of LIC’S research reinforces the farmerowned co-op as a world leader in pastoral dairy genetics. “Nature Genetics publishes the very highest quality research in genetics globally, in animal and human research alike. We were delighted to hear they had accepted our research paper on the production variant discoveries, further validating the cuttingedge genetic discovery work our R&D team is carrying out.” The discoveries were made possible by genetic mapping studies on LIC’S large DNA sequencing and animal production datasets, as well MBIE Endeavour funding. “Our Next Generation Genomic Selection programme has enabled a detailed understanding of the effects of the variants identified and will enhance future discovery, as data and methods continue to develop to identify new variants at lower frequencies in New Zealand dairy animals.” LIC is one of the biggest investors in research and development for the primary sector, spending $16m in 2019/20.