The impact of weaning age and/or supplemental liquid feed in the farrowing pen on pre- and post-weaning feed intake was investigated. The supplemental feed systems consisted of a milk replacer from day 2, changed to a cereal-based liquid feed 12 days after birth. By continuing with the same feed post-weaning, but in dry form, we hypothesised that the feed change would be less abrupt and would increase feed intake post-weaning. The study consisted of 24 sows and their litters in a 2 × 2 factorial design. The design factors were weaning age (WeaningAge) at either 24 days (D24) or 35 days (D35) and with or without access to supplementary liquid milk replacer/feed (+SupFeed/-SupFeed). Individual eating behaviour pre- and post-weaning was observed on video recordings. Results of this study showed that the transition from milk replacer to liquid feed during lactation (on day 12) caused a drop in number of bouts observed per piglet of ingesting supplemental feed (day 11 compared to days 12 and 13) (p < 0.05). Independent of WeaningAge, more bouts of ingesting supplemental feed per piglet were seen the day before weaning in piglets with lower suckling success (p < 0.05). WeaningAge D35 compared to D24 shortened the latency to the first observation of solid feed consumption and drinking water, and litters weaned at D35 had more eating and drinking bouts per piglet the first 12 h post-weaning (p < 0.05). WeaningAge D35 also increased eating bouts the day after weaning (24 to 36 h post-weaning) (p < 0.05), 6 days after weaning (p < 0.05) and the daily amount of feed consumed per pen the first week post-weaning. Access to supplemental feed shortened the latency to the first feed consumption but increased the latency to water consumption within 12 h of weaning (p < 0.05). Access to supplemental feed and the mean frequency of feed intake pre-weaning (days 11-13) did not affect the frequency of feed or water consumption per piglet post-weaning (p > 0.1). Nor did access to supplemental feed affect the daily amount of feed consumed per pen from weaning to 6 days after (p > 0.1). The results of the present study show that later weaning, to a greater extent than supplemental feed pre-weaning, could increase feed intake post-weaning. However, the effect on gut health and diarrhoea needs to be investigated to evaluate whether it is an effective alternative to antibiotics and medical zinc.
