The relationship between duodenal myoelectric activity and liquid food intake was investigated in eight conscious piglets with bipolar electrodes implanted on the wall of the duodenum. Piglets were fed with commercial milk formula and the effects of volume and feed dry matter intake on duodenal myoelectric activity were measured by means of an analog-digital recording system. The cyclic pattern of duodenal myoelectric activity, i.e. the migrating myoelectric complex (MMC), was preserved when piglets received small meals at regular intervals. The duration of the whole MMC cycle, as well as the duration of phase II of the MMC, were only weakly correlated (r = 0.2, P <0.05 for both parameters, respectively) to the amount of ingested food. However, the increase of the amount of feed dry matter intake of a meal from 2.1 to 4.5 g kg(-1) of live body mass (LBM) as well as an increase of volume of a meal from 13 to 26 ml kg(-1) LBM significantly increased the duration of the MMC cycles (P <0.05) due to the elongation of phase II of the MMC (P <0.05). The present study shows that in piglets fed with a liquid diet the upper gut motility response to food is similar to that previously observed in adult animals. (c) 2007 Elsevier B.V. All rights reserved.