Investigations on feed intake and social behaviour of fattening pigs fed at an electronic feeding station

For the study from a total of 679 female pigs kept in a progeny test station in 64 groups mostly with 12 pigs each, the data from all visits at an electronic feeding station (EFS) were analysed. In 93 pigs (8 groups) all agonistic interactions at the EFS were recorded in continuous observations using infrared video technique during 3× 48 h at the beginning, in the middle and at the end of the fattening period and registered in a 12 × 12-matrix in order to calculate the rank index (from −1 to +1) and rank place (from 1 to 12) for each animal. All EFS visits, the duration of each stay at EFS (MDS) and the recorded amount of feed at each EFS visit (MFI) were downloaded from the Compident EFS for the 3× 48 h periods during the whole observation period. Means were calculated for pigs with high (1–6) or low rank position (7–12) and for pigs according to their individual rank places (1–12). The pigs with the fewest EFS visits had a significantly longer MDS (5.1 min) and a significantly higher MFI (176.7 g) than pigs which came to the EFS most frequently (MDS = 3.4 min, MFI = 109.8 g). At all stages of the fattening period, high ranking pigs had less EFS visits during 48 h, a longer MDS and a higher MFI compared with low ranking group-members. The two pigs with the highest rank places of each group had significantly less visits at the EFS (745) during the whole observation period than subdominant pigs (1637). Dominant pigs occupying the first three places in the social hierarchy of the group had a longer MDS (6.6 min on average) and in tendency a higher MFI (228 g) compared with subdominant pen-mates (3.2 min, 101 g). The routinely collected and stored data (EFS visits, MDS and MFI) of the Compident EFS could be used as a tool for phenotyping the behaviour of fattening pigs, especially the feed intake and social behaviour which might be leading to long-term breeding decisions.