Science of Merino: MERINOSELECT brings worlds largest genetic evaluation into producers’ hands

Merinos represent more than 70 per cent of the national breeding flock in Australia. MERINOSELECT is the world leading genetic evaluation for Merinos, consisting of 4 million animals, with 74 traits to use for genetic selection and 465,000 genotypes. Within the Merino breed, there is an incredibly diverse range of production systems and animal types, from fine wool flocks located in areas of high rainfall to flocks focusing on wool cut and a self-replacing breeding system or more dual purpose and reproduction focused flocks. Genetics research and development is unique in that large scale data collection over many years is required to capture variation and genetic trends. MERINOSLEECT is underpinned by leading research and revelopment and is the largest sheep genetic evaluation of its type in the world. One key element is the use of genomic information. The use of genomics within the evaluation is underpinned by what are known as reference populations — a group of animals that are measured for a trait and those same animals are also genotyped. Reference populations contributing to MERINOSELECT include the Meat and Livestock Australia Resource Flock and the Australian Wool Innovation Merino Lifetime Productivity Project, each seeing large scale recording of hard-to-measure traits ranging from lifetime wool productivity, to eating quality and reproduction. The MLA Resource Flock sees head-to-head comparison of different breeds and industry sires across Australia, including a site managed by DPIRD in Katanning.. This project aims to record progeny for eating quality, methane and feed intake on progeny from 150 industry sires annually. All progeny are also genotyped, forming a valuable genomic reference population for the Sheep Genetics LAMBPLAN and MERINOSELECT evaluations. Historically there has been great success in using the MLA Resource Flock to drive new developments and capture information on emerging traits of interest, allowing faster implementation into industry than if relying on breeder recording alone. Ram breeders are able to annually nominate sires into the MLA Resource Flock. Sires are selected based on diversity to other animals that currently exist within the genomic reference population. Nominations open in September-October annually. Ram breeders are strongly encouraged to nominate sires from their breeding program. A reference population is any animal within MERINOSELECT that has a genotype and phenotypic measurement taken for a trait. Some traits, such as weaning weight, have very large genomic reference populations as it is a trait that is easy to measure. Others, like eating quality, have a smaller reference population as it is a trait that is only typically recorded in research projects like the MLA Resource Flock. Genomic selection has seen the rate of genetic progress increase across many industries around the world, and the sheep industry in Australia is no exception. It accelerates genetic progress by increasing the accuracy of traits that are typically deemed as “hard to measure” or are measured later in an animal’s life like reproduction and adult wool traits. Genotyping young animals allows these selection decisions to be made earlier in life, more accurately, which ultimately leads to greater genetic progress. Utilising genomics technologies for parentage assignment and increased accuracy of Australian Sheep Breeding Values has led to the MERINOSELECT analysis approaching half a million genotypes that are routinely used in its evaluation. Industry benefits from the large genomic reference population available within Merinos through development of commercial flock-based tools of selection such as the Flock Profile. Drawing on the large amount of phenotypic and genomic recording within the MERINOSELECT analysis, commercial producers can benchmark their flock average against industry to get a better picture of genetically where they sit for traits of interest to their production system. Producers are provided a report comparable to MERINOSEELECT percentile bands to assist when purchasing rams to ensure they are selecting genetics to drive genetic progress towards their breeding objective. Merinos are in a great position to capitalise on the work and recording being carried out within industry. More data, more phenotypes, more genotypes contributing to the analysis has seen an increase in selection accuracy, pedigree accuracy, earlier selection and genetic gain being made on hard-to-measure traits of importance. This has placed ram breeders and buyers in a position to make the most of the science behind MERINOSELECT within their flocks. Chloe Bunter is the development officer for MERINOSELECT.