Different roughages to organic growing/finishing pigs — Influence on activity behaviour and social interactions M. Høøk Presto a, ⁎, B. Algers b , E. Persson b , H.K. Andersson a a Dept. of Animal Nutrition and Management, Swedish University of Agricultural Sciences (SLU), PO Box 7024, SE-750 07 Uppsala, Sweden b Dept. of Animal Environment and Health, Swedish University of Agricultural Sciences (SLU), PO Box 234, SE-532 23 Skara, Sweden article info abstract Article history: Received 4 June 2008 Received in revised form 8 October 2008 Accepted 11 October 2008 The effect of roughage on pigs' activity behaviour and social interactions was investigated at four observation occasions in this study, which was performed during two years and included two experiments of organic growing/finishing pigs. In experiment 1, 377 pigs were allocated randomly to either a control treatment (C) or one of three treatments with access to additional roughages; hay (H), grass silage (GS) or whole crop barley silage (BS). In experiment 2, 138 pigs were randomly allocated to the C or the GS treatment. Pigs were housed indoors with straw in the lying area and with access to a concrete outdoor run, where H, GS and BS pigs were given roughages ad libitum in hedges. Pigs given roughage were staying outdoors significantly more frequently than control pigs (p =0.031 in experiment 1 and p = 0.002 in experiment 2) and were more active (p = 0.034 and p =0.006, respectively). C pigs were rooting in straw more often than GS pigs and tended to root more often than BS pigs, which suggests that pigs with additional roughage are motivated to use it to explore and forage. However, no difference in time spent on eating the different roughages was found. Indoors, the frequency of aggressive behaviour in the lying area was lower for pigs with access to roughage than for pigs in the control treatment in experiment 1 (p =0.009) and was lower, though not significantly, in experiment 2 (p =0.121). Our results confirm that access to additional roughage in the outdoor area significantly influences the pigs to go outdoors more frequently and to be more active, and reduces the aggressive behaviour among the pigs. © 2008 Elsevier B.V. All rights reserved. Keywords: Activity Behaviour Aggression Growing pigs Organic production Roughage 1. Introduction Pigs in organic production should be able to express their natural behaviour for rooting and grazing. Larger areas and outdoor runs occupy pigs giving them more possibilities to be active. Roughages such as grass (fresh or dried), silage or straw should be offered in unlimited amounts (EC, 1999). According to Swedish standards (KRAV, 2007), high quality hay or silage should be included in the diet. Pigs have a capacity to digest forage fibres in the hindgut (Andersson and Lindberg, 1997) and roughages might, due to high fibre content, be a way to improve the well-being of pigs because they positively affect the development of the micro flora and epithelium in the gut (Fernandez and Danielsen, 2002). Roughages also positively affect pigs by increasing their motivation to explore and forage (Roberts et al., 1993; Vestergaard, 1996). It has been shown that roughage can be included in the total diet up to 18–19% of dry matter without refusals (Carlsson et al., 1999) and that pigs with a live weight of 60 kg or more, are able to consume 10% of the energy from roughage (Jensen and Andersen, 2002). Danielsen et al. (1998) showed that when an amount of feed was replaced with roughage, higher meat content and better feed efficiency but slower growth rate was obtained. All aspects of animal production relate to the animals' behaviour (Broom et al., 2007) and the environment influences the well-being and the behaviour of pigs. Pigs are curious and have a well-developed exploratory behaviour (Wood-Gush and Vestergaard, 1991). Exploring, foraging and rooting behaviours are expressed largely in the pigs' general Livestock Science 123 (2009) 55–62 ⁎ Corresponding author. Tel.: +46 18 672044; fax: +46 18 672995. E-mail address: Magdalena.Presto@huv.slu.se (M. Høøk Presto). Contents lists available at ScienceDirect Livestock Science journal homepage: www.elsevier.com/locate/livsci 1871-1413/$ – see front matter © 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.livsci.2008.10.007