Feed intake behaviour of piglets in single and group suckling pens

Early contact to plant-based feed (creep feed) should stimulate the adaption of the gastrointestinal system and promote gut development, with the desired effect of less physiological stress at weaning, lower incidence of diarrhoea and higher growth rates due to better feed efficiency. From May 2013 to July 2015 we studied the feed intake behaviour of piglets during a 6-week suckling period (93 farrowings, 917 weaned piglets). The piglets were born in one of two different free farrowing systems for one sow, after two weeks half of the farrowing batches were transferred to a group suckling system from their initial housing system (2x2 factorial design: initial housing organic or conventional and subsequent grouping or not). We observed the time the piglets began to consume relevant amounts of creep feed, the quantities they consumed, their growth rates and the frequency and length of their visits at two locations for feeding (piglet area, trough of sow). Additionally, we tested whether intervisibility between the two feeding areas influenced feed intake of the piglets. Piglets that remained in the single suckling systems consumed 18.6±4 g piglet-1 (organic) and 26.1±4 g piglet-1 (conventional) on days 7-9 after the beginning of the creep feeding period. In the same time period, piglets transferred to the group suckling system from organic pens consumed 7.1±4 g piglet-1 and piglets from conventional pens 16.2±4 g piglet-1. Piglets that remained in the organic single suckling pen were heaviest at weaning (11.9±0.2 kg) but consumed only 43.6±19 g piglet-1 on days 22-24 after beginning of the creep feeding period. Piglets in the group suckling system consumed 125.0 g piglet-1 (conventional) and 236.4 g piglet-1 (organic), but weighed only 10.6 kg (conventional) and 11.0 kg (organic).Subsequent grouping and the interaction of initial housing, grouping and day had a statistically significant effect on feed intake (grouping: p=0.03; interaction: p<0.001) and body weight of piglets (grouping: p=0.01; interaction: p<0.001). Influence of birthpen was significant only for body weight (p<0.001).Within the four hours observed (11:00-13:00; 16:00-18:00), the piglets visited the feeding places on average 4 times a day, with one peak at the beginning of the feeding phase and another one close to weaning. Piglets in the group suckling system spent most of the time at the creep feeding place (organic: 9.9±1 min, conventional: 9.6±1 min) and less than one minute at the sow’s trough. Piglets in the organic system spent the least amount of time at the feeding place (2.5±1 min, statistically significant) and most of it at the sow’s trough (4.6±1 min). Piglets in conventional pens were observed for 7.2±1 min at the creep feeding place and 8.2±1 min at the sow’s trough. Piglets consumed more at feeding places when provided intervisibility with the sow’s trough, but the difference was not statistically significant. Overall, the prevalence of pigs visiting the creep feeding area was as high as of pigs visiting the trough of the sow.The results suggest that to promote feed intake at the creep feeding place, group suckling is preferable to single litter suckling systems.