AN APPROACH TO PREDICTION OF FEED-INTAKE IN GROWING PIGS USING SIMPLEBODY MEASUREMENTS

Several data sets were used to test the proposition that feed intakes can be predicted from knowledge of simple measurements of pig live wei ght and fatness. Key equations are the prediction of lipid mass (Lt) a nd protein mass (Pt) from P2 fat depth and live weight (Wt); Lt = 1.12 (0.19Wt + 0.78P2 - 9.2), Pt = 0.439(0.41Wt -0.52P2 + 2.4), and the pr ediction of daily metabolisable energy intake (EIp) as the sum of the needs for protein retention (Pr), lipid retention (Lr) and maintenance , EIp = 52Pr + 53Lr + 0.44Wt(0.75). The approach is found to be sound for the prediction of the average daily intake of groups of pigs over a given weight range; but was less accurate in the prediction of the f eed intake of individual pigs in some, but not all, of the populations examined. For the 10 groups of pigs tested, mean actual and predicted feed intakes (kg/day) were respectively: 2.31 and 2.35; 2.14 and 2.18 ; 3.15 and 3.03; 2.81 and 2.80; 1.87 and 2.08; 1.96 and 2.24; 2.01 and 2.04; 2.03 and 2.06; 2.20 and 2.12, 1.88 and 1.78.