Feeding beaviour of slaughter pigs (Sus Scrofa) kept in a Swedish conventional system

Sammanfattning: The management and keeping of slaughter pigs are normally highly controlled and achieving a good feed effiency is one of the pork industriy’s main goals. When being kept in a conventional system the pigs do not have a good opportunity to perform natural feeding and foraging behaviours which could lead to frustration and a negative welfare. Pigs are as well commonly kept at a high density and therefor have difficulties keeping a distance to eachother. This could also lead to increased frustration and aggressive encounters during feeding. Twelve pens were liquid fed three times a day, with observations made during their lunch feeding. The actual feeding had a short duration in all pens with a maximum time of approximately five minutes. Results show that pigs were lying down and being inactive during the main time of the observations. Other commonly performed behaviours were substrate explore, fixtures explore, nosing pig, walking, eating and head throwing. In correlation with feeding the three latter behaviours increased, but only walking was significant (P<0.05, F=15.52). A delayed feeding did not seem to effect animals negatively as the pigs in the four latest pens were lying down (F=3.30, P=0.103) and seemed more calm in comparison with the four first fed. When comparing pens being mixed or not, mixed pens performed fixtures explore (F=13.28, P< 0,002) more often and lying (P<0.05, F=32.44) to a less extent. The mixed pens also had a higher average slaughter weight (P<0.05, T= 2.91). More research considering long-term effects of mixing pigs should therefore be prioritized. Belly nosing was performed frequently in all pens and since this behaviour could be an indicator of stress, it should be further analyzed. Inactive behaviour demonstrated to highest extent by all pigs could be a result of different causes. Though, the author believes that is caused by boredom and not having access to perform other behaviours. This is why more effort should be put into prolonging the feeding time and keeping the pigs occupied during a larger part of the day.