PSVI-6 Effect of season on the feeding behaviour and kinetics of daily feed intake of high-prolific sows during lactation

Heat stress can cause changes in the feeding behaviour of lactating sows. The present study aimed to evaluate the impacts of season on the feeding behavior and kinetics of daily feed intake of modern high prolific sows under tropical conditions. A total of 80 high-prolific mixed parity sows divided into 10 batches of 8 sows each were used. Individual feeding behaviour was recorded during the ad libitum period (between d 1 and 23 of lactation), using an Automated Intelligent Feeder (AIF; Gestal Solo, Jyga Technology, Canada). Daily feed intake during lactation was affected by season (P < 0.001), and the feed intake was less during the hot season (5.66 vs. 7.23 g/d; Figure 1a). The daily ingestion time was less in the hot season (36.8 vs. 72.3 min/ d; P< 0.01) and the ingestion time per meal was also lower in the hot compared to the cool season (5.7 vs. 7.5 min/ meal; P < 0.05). The hot season showed a lower (P < 0.01) rate of daily intake when compared to the cool season (36.8 vs. 72.3 g/ min). Sows showed a higher diurnal feed intake (3,546 vs. 2,901 g/ d), whereas meal frequency was not affected (4.2 meals/ d, on average). Irrespective of the season, the nycthemeral pattern of feed intake peaked twice daily: between 0200 and 0900 h and between 1600 and 2000 h (Figure 1b).The present study confirms that lactating sows do not change much their feeding pattern according to season, meaning that they tend to keep the same feeding behaviour during both seasons, with a more pronounced intake between 0200 and 0900 am, approximately 80% of their total daily intake. Sows may not change feeding pattern according to season, but reduce significantly voluntary feed intake under hot climate conditions in order to reduce the thermal effect of feed.