| 67 Faster genetic progress being made Richard Loader Genotype, measure and select is the way to make faster genetic progress through more accurate breeding values, says Shannon Clarke, AgResearch’s principal scientist. “This is how the terminal sire breeders within the meat quality progeny test programme, known as the South Island Genomic Calibration (SIGC) project, have continued to produce rams with increased meat quality. Specifically, they have been staying ahead with the use of the latest genomic profiling tools from GenomNZ (genomnz@agresearch.co.nz), coupled with early selection of the best rams.” The rams submitted to the SIGC have their progeny evaluated, however, it is the genotyping within their home flock that enables the genetic linkages to disseminate the genomic information further. Genomically enhanced breeding values are delivered to all young lambs from flocks submitting rams to the SIGC prior to weaning. The flock, now located at Pamu Freestone Farm, consists of ewes that have been mated to ~300 terminal breed rams from around the country over the past seven years, whose DNA has been profiled. “Industry implementation of genomic predictions for growth, yield and meat quality in terminal sheep sires requires continued testing in the training flock (SIGC) to maintain accuracy and validation of the meat quality traits,” explains Shannon. “Lambing dates and weights are recorded to determine exact growth rates, each lamb is tissue sampled at docking and genotyped.” When the lambs are processed, the team at AgResearch work with the processor to capture a series of measurements to determine the tenderness and IMF (Intermuscular Fat) of each lamb, along with pH, meat and fat colour and visual marbling. Shannon says the ground-breaking work being done in the SIGC flock has resulted in the ability to predict a lamb’s eating quality via a DNA test, using the AgResearch Sheep Genomic 60Kplus SNP chip (genomnz@agresearch.co.nz). “This has been achieved without affecting genetic progress for other terminal traits, as evidenced in the graph, with the New Zealand Terminal Worth with Meat Quality indexes increasing as a result of the industry implementation of meat quality genomic breeding values over the past seven years. The collection of detailed meat quality measures in the SIGC progeny underpins the meat quality index and enables predictions to the terminal sire industry through their flocks’ genetic linkage to the SIGC flock. This will enable commercial farmers to breed lambs with better quality meat through buying rams selected for better eating quality. RURAL SERVICES » AgResearch (Invermay) Ultimately the end result is the breeding of a consistently better and more enjoyable eating experience for the consumer.” This AgResearch Sheep Genomic chip has been developed by AgResearch scientists who strive to deliver leading-edge technologies to NZ breeders, ensuring the NZ sheep meat industry can meet the expectations of our international markets. The SIGC is a partnership of researchers and industry groups; Beef + Lamb New Zealand (B+LNZ) Genetics, Pamu Farms of New Zealand , Focus Genetics, AgResearch, along with a number of breeders representing SufTex, Suffolk, Texel, Wiltshire, Charollais, Hampshire, and terminal composites. SIGC also acknowledges those that have been with the project since establishment including Focus Genetics, Kelso Genetics, The Premier Suftex group and the Southern Suffolk group.
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