7th World Congress on Genetics Applied to Livestock Production, August 19-23, 2002, Montpellier, France THE USE OF PROTEIN AND LIPID DEPOSITION TO DETERMINE SELECTION GOALS AND THEIR ASSOCIATION WITH CARCASS CUTS IN SWINE S. Landgraf 1 , R. Roehe 1 , A. Susenbeth 2 , U. Baulain 3 , P.W. Knap 4 , H. Looft 4 , G.S. Plastow 4 and E. Kalm 1 1 Institut für Tierzucht und Tierhaltung, Christian-Albrechts-Universität zu Kiel, D-24098 Kiel, Germany 2 Institut für Tierernährung und Stoffwechselphysiologie, Universität Kiel, D-24098 Kiel, Germany 3 Institut für Tierzucht und Tierverhalten, Bundesforschungsanstalt für Landwirtschaft (FAL), D-31535 Neustadt-Mariensee, Germany 4 PIC Deutschland, Ratsteich 31, D-24837 Schleswig, Germany INTRODUCTION Biological growth models are of increasing interest in animal breeding. For example, De Vries and Kanis (1992) developed a biological growth model to optimise selection for feed intake capacity. For this biological growth model the input parameters of maximum protein deposition rate and minimum lipid to protein deposition ratio have to be known. In order to optimise the feed intake curve based on this biological growth model, the input parameters have to be known for each stage of growth. Different methods can be used for measuring protein and lipid deposition rate on live animals (e.g. deuterium dilution technique, magnetic resonance tomography (MRT)) or on slaughter animals in a serial slaughter trial with the entire body chemically analysed. All these techniques are very expensive and can only be obtained in an experimental trial. Therefore, indicator cuts to estimate the protein and deposition in different stages of growth are of high interest. For selection of feed intake over the entire growth period, the maximum protein deposition rate and minimum lipid to protein deposition ratio have to be known. Knap (2000) showed that the Gompertz function can be used to estimate these parameters. The use of the Gompertz function is only possible when the animals were tested over a long period as in the present study. Therefore, the objectives of this study were to obtain indicator cuts for protein deposition and lipid deposition rate and to obtain parameters for maximum protein and lipid deposition estimated by using nonlinear Gompertz function, which can be used for selection to optimise feed intake curve based on a biological model. MATERIAL AND METHODS Data were obtained in a three generation full-sib design, which will be used finally to identify the genomic regulation of protein and lipid deposition rate. However, the first goal was to obtain protein, lipid and ash deposition during growth and its association with carcass characteristics. The base generation (F 0 ) consisted of 8 unrelated boars of a sire line and 32 unrelated sows of a dam line, which were mated to get the F 1 generation. Animals not used to create the F 2 generation were tested on station to obtain protein, lipid and ash deposition at 15, 30, 60, 90, 120, 140 kg. Protein and lipid deposition was measured on all tested animals by Session 11. Growth and meat quality Communication N° 11-08