WA woolgrowers could boost profitability with in-shed testing, according to latest research by Agriculture WA. Research officer Andrew Peterson said dividing wool into fine, medium and broad lines after in-shed testing allowed growers to capitalise on higher returns for fine wool, while using the same information to select sheep based on wool diameter. "Growers with an average fibre diameter of 20 to 22 microns would make the most gains from accurate sorting of their wool using in-shed testing," Mr Peterson said. "Broader and finer clips also gain, but not as much. "In-shed testing also makes it easy to cull sheep with lower fleece value, by removing those with low fleece weights and broader micron wool." Mr Peterson said Agwest's Wool Program had been evaluating the economics of in-shed testing on several commercial properties in the the past few months. Participating woolgrowers included Colin, Lyn and Dougal Young at Brookton, Nils Blumann at Esperance and Nepowie stud at Narrogin. Mr Peterson said the greatest advantage came from testing younger breeding stock to identify the poorest performers. Extra profit from more accurate sorting of wools helped to subsidise the cost of testing every animal. Dougal Young said about 1000 ewe hoggets were tested before shearing on their property with the fine lines averaging 17.4 microns, medium at 18.9 and broad at 19.8 microns. "We were particularly amazed at the huge variation among our sheep where value of individual fleeces varied from $7 to $78 and averaged $29," he said. "On this experience, we believe the system could benefit many growers by both improving prices and helping to remove the poorer performing sheep."