The objective of this study was the development of a genetic statistical method for longitudinal data of daily feed intake in growing pigs using random regression models (RRM) in order to change the pattern of feed intake by selection. Besides a quadratic RRM for additive genetic effects, different combinations of covariance structures for permanent environmental effects using RRM and for temporary residual effects were fitted to individual information from 5245 boars (2938 of line 3, 2307 of line 4) in order to obtain the best fitting model for daily feed intake recorded during a test period of 10 weeks. Based on Akaike’s Information Criterion, the parsimonious model included a constant diagonal covariance structure for the permanent environmental effects and a heterogeneous autoregressive-moving-average structure of order (1,1) for temporary residual effects. Estimates of the autocorrelation were 0.80 (line 3) and 0.81 (line 4) and estimates of the moving-average components were 0.15 (line 3) and 0.11 (line 4). Estimates of heritabilities were low and increased from 0.02 to 0.06 during the test, with the highest estimates in the seventh week on test. The low heritabilities were only due to a higher residual variance when using individual daily records of feed intake, whereas additive genetic variances (0.01 to 0.04 kg 2) were similar to estimates using average records of feed intake. Genetic correlations between intercept and linear regression coefficients were positive within 0.57 and 0.55, those between intercept and quadratic regression coefficients were negative within −0.77 and −0.89, and those between linear and quadratic coefficients were within −0.48 and −0.61 for lines 3 and 4, respectively, indicating the opportunity for changing the feed intake pattern. Additionally, eigenfunctions obtained from the additive genetic (co)variance matrix indicated that a genetic change in feed intake pattern is achievable, e.g. the second major eigenfunction, which explained about 10% of the additive genetic variation, allowed selection for a high increase in feed intake at the beginning of the test period and for reduced feed intake at the end of the test period in order to improve feed efficiency.