A large crossbred sheep breeding project (LS2202), funded by Defra and MLC set up in 1997 involved IRS at Aberystwyth, ADAS at Pwllpeiran and Rosemaund and SAC at Edinburgh. The objective of the project was to provide essential information for the development of a multi-trait selection index for improving carcass quality of crossing sire sheep and their crossbred progeny without compromising their reproductive performance and maternal ability. The project consisted of two overlapping phases, namely; a ‘production’ (1997-2000) and an ‘evaluation’ phase (1999-2003). This project had an initial duration of six years, and has recently been extended for a further 3.5 years until December 2006 to complete the ewe ‘evaluation’ phase and to collect longevity information on this unique resource of crossbred ewes. Because of the constraint on resources, it was not possible to involve all the main hill ewe breeds at the outset, and a ‘bolt-on’ demonstration project was set up at Newton Rigg College of Agriculture, involving the Swaledale breed, to aid the technology transfer process. A request is now made to extend this demonstration project for a further three years to run in synchrony with the main project which finishes in December 2006. In the ‘production’ phase, during three production years (2003/04 – 2005/06), 150 Swaledale hill ewes will be naturally mated with performance-indexed Bluefaced Leicester rams sourced from the Sire Reference Scheme. This phase should produce around 200 lambs per year which will be closely monitored for growth. Of these, the male lambs will be finished and carcass information collected. Around 75 ewe lambs per year will be retained for further evaluation as breeding females. During the ‘evaluation’ phase, approximately 75, 150 and 180 Mule ewes in 2003/04, 2004/05 and 2005/06 respectively, will be mated to high index terminal sire rams and their reproductive performance assessed. Over three years, a total of around 700 crossbred lambs will be assessed for growth and carcass attributes. An Open Day will be held at Newton Rigg each year, to demonstrate the progeny being produced and to provide a focus for presenting results from the main project to a wide audience of farmers. Because Newton Rigg is now one of the three ‘focus farms’ of the Northern Uplands Sheep Strategy (NUSS) initiative, it is planned to link our promotional activity with that of NUSS, as we began to do during 2003. In this connection, it is envisaged that project results will also be presented at one or two other NUSS events each year. These promotional activities will be designed to encourage rapid uptake of the emerging technology by the leading sheep breeders in the industry, and will complement other promotional activities already planned as part of the main project.