Within-flock selection to reduce fibre diameter and increase fleece weightin Merinos - Response to the first round of selection in the Trangie QPLU$lines

Profits from Merino wool production can be substantially and permanently im proved by selective breeding. Given that fleece weight and fibre diameter a ccount for around ninety percent of the value of individual fleeces, they a re logical breeding objectives for Merino breeding programs focused on maxi mising improvement in profit. Because fleece weight and fibre diameter are both moderately to highly heritable and exhibit considerable between-sheep, within-flock variation, they are also ideal selection criteria to achieve that objective. This paper presents the first estimates of response in mean fibre diameter and clean fleece weight in a number of selection lines crea ted in fine, medium-Peppin and broad wool Merino strains selected on variou s indexes of measured fleece weight and measured fibre diameter.