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Beyond the Bale : Aug 07 - Sep 07 Supplement
BREEDING FOR PROFIT SUPPLEMENT BEYOND THE BALE 13 By Fiona Conroy Photo by Tim Dub Within a decade Tasmanian woolgrower Richard Gardner has cut the average fibre diameter of his clip by four microns. The dramatic shift has been made possible by using on-farm fibre measurement (OFFM) as an integral part of his sheep selection program. The technology has allowed Mr Gardner to accelerate his genetic improvement by culling any 1.5-year-old ewes outside his target micron and fleece weight range. Mr Gardner began using objective measurements in his commercial Merino flock on 'Annandale' at Turnbridge in the Midlands in 1996. "In the first two years we took mid-side samples from several hundred randomly selected young ewes to gauge the micron spread and average," he says. "The result in the first year showed we had an average micron of 21.7 with fleece values for individual animals ranging from $12.21 to $30.11 based on prices at the time. "The range demonstrated the potential to improve sheep profitability through selecting for micron and fleece weight, so we decided to start testing the entire drop of young ewes in subsequent years." The next year a Fleecescan unit was used when the young ewes were being shorn so that each animal could be measured for micron and fleece weight. A couple of years later Mr Gardner switched to using the OFDA2000 because of its smaller size. Micron and weight for each fleece are linked to each animal's individual tag number. Two extra staff are required in the shed when the young ewes are being shorn. The costs involved include $1.30 per head for the OFDA and two extra labour units for one and a half days. Tasmanian-based Roberts Ltd carries out all the measurements and is accredited under AWI's OFFM uality Assurance program. Roberts then uses each animal's data for fleece weight, micron and coefficient of variation (CV) for fibre diameter to rank each young ewe using the 12 per cent micron premium (MP) breeding index. FIBRE MEASUREMENT CRITICAL TO TASMANIAN GROWER Using on-farm fibre measurement has cut the average fibre diameter of the clip by four microns here?' now that we have reached our target micron. I think we will probably aim to put more selection pressure on increasing fleece weight and less on reducing fibre diameter." AWI program manager for sheep productivity Dr Troy Fischer says OFFM is important for growers wanting to assess their flock's performance and as a breeding and selection tool. Woolgrowers wanting to explore their options using the technology can access a free web-based software program called the OFFM calculator. The calculator, developed by AWI and the Sheep Industry Cooperative Research Centre (CRC), sets out the expected benefits of using OFFM to change flock structure and breeding and selection criteria over time. The program also links into current wool prices to show the economic return of using OFFM results in clip preparation. The OFFM website includes a list of ON-FARM FIBRE MEASUREMENT 16 17 18 19 20 21 22 23 FIBRE DIAMETER 1 2 3 4 5 6 GREASY FLEECE WEIGHT YEAR 1997 1998 1996 2000 2001 2002 1999 2003 2004 2005 2006 Fibre diameter Greasy fleece weight 'Annandale' 1.5-year ewes' fibre diameter, greasy fleece weight Within a decade Tasmanian woolgrower Richard Gardner has cut the average fibre diameter of his clip by four microns. Mr Gardner has so much confidence in this index that he uses it to make 95 per cent of his culling decisions, with just five per cent of young ewes culled on visual appearance. "After 10 years the micron of our clip has dropped and our sheep still look good visually," he says. "We've been able to use objective measurement to put some fairly dramatic selection pressure on our sheep in terms of lowering micron. The next challenge will be 'where do we go from accredited OFFM service providers who have undergone quality assurance training, an annual proficiency trial and random auditing. Using a quality-assured OFFM provider ensures the most accurate data is provided, so that correct decisions are made using that information. Dr Fischer adds that testing using an accredited OFFM provider is a requirement for ram breeders supplying measurements to Sheep Genetic Australia's database. ú More information: www.wooloffm.com.au
Oct 07 - Nov 07
Aug 07 - Sep 07