PSX-22 Evaluation of average fiber diameter measurements by FibreLux micron meter and OFDA2000

Abstract Average fiber diameter (AFD) of wool is one of the most important measurements for determining the value of wool and for improving its quality through selective breeding. A new instrument the FibreLux Micron Meter™ (FL) was compared to the OFDA2000, both of which are meant for on-farm measurement of AFD. Mid-side samples were collected, a staple removed and measured on the OFDA2000 and then on the FL. Measurements with the OFDA2000 and FL were made on-farm prior to shearing. The same staple was taken to the laboratory and measured on the Laser Scan (LS) a reference method for AFD. All measurements were compared using the IWTO-0 Appendix B (2002) procedure for comparison of methods. The OFDA2000 compared favorably to the LS. The slope did not differ from 1 (P = 0.44), there was no level dependent bias(P = 0.46), and r = 0.94. Compared to the LS the FL slope (1.15) differed from 1 (P = 0.03), and there was level dependent bias (P = 0.03), and r = 0.77. The FL underpredicted AFD in fine wools and overpredicted AFD on coarse wools. Samples that measured 15 µm by the reference method would be expected to measure 14.3 µm on the FL and samples that measured 25 µm on the LS would measure 25.7 µm on the FL. A comparison between the FL and the OFDA2000 showed that the results were similar to previously reported results from our laboratory that were conducted on samples in the lab. The FL is suitable for on-farm testing of AFD for selecting animals to improve AFD and for classing wool.