Effect of straw on the behaviour of growing pigs

Abstract

The effects of straw on the behaviour of young growing pigs were studied in two experiments. In Experiment 1, group of three pigs, aged about 7 weeks, were housed in raised decks with or without straw bedding. Time-lapse video recording showed no major differences between treatments in the amount or daily pattern of overall activity and feeding. Detailed observations showed that bedding reduced the incidence of rooting and chewing on pen-mates, but had little effect on other social activities such as mounting and aggressive biting. Experiment 2 compared groups of eight growing pigs aged about 10 weeks, housed in floor pens with or without a small amount of straw provided daily in a rack. Pigs with straw concentrated more of their daily activity into the period when straw was fresh, but the total amount of overall activity and time spent feeding were not affected. Rooting and chewing of pen-mates were the only social activities reduced by the provision of fresh straw. In these studies, where straw was not required to compensate for deficiencies such as low temperatures or hunger, the one major function of straw was to provide a stimulus and outlet for rooting and chewing, with a resulting reduction in such activities directed at pen-mates. lNTRODUCTION The provision of straw is widely considered to be beneficial for the comfort and well-being of pigs (Müller et al., 1979; van Putten, 1980). However, the actual effects of straw are complex and depend greatly on the type of pigs and the conditions under which they are raised (see e.g. Stephens, 1971; Schouten, 1986; Edwards and Furniss, 1988). For closely confined sows on a concrete floor and fed a restricted diet, straw is thought to have three distinct effects: (i) as bedding it improves the thermal comfort and perhaps the physical comfort of the floor; (ii) it is eaten in appreciable amounts and results in greater filling of the gut; (iii) it serves a "recreational'' function as a stimulus and outlet for the rooting and chewing activities that are natural to pigs (Fraser, 1975; Sambraus and Schunke, 1982). The situation is different for younger, growing-finishing pigs. Firstly, because these animals are often fed ad libitum or nearly so, any filling of the gut with straw is of questionable benefit. Secondly, the relationship of straw to floor comfort depends greatly on environmental temperatures: growing pigs prefer to lie on straw under cool conditions, but prefer bare floors at higher temperatures (Fraser, 1985; Marx and Mertz, 1989). This leaves the "recreational" effect of straw as the one major potential benefit that remains when feeding levels and environmental temperature do not create additional needs. Although several studies have reported apparent effects of straw on the behaviour of growing pigs, the research has generally involved a confounding of straw with other variables. For example, Buré (1981) reported that weaned pigs housed with straw performed less "abnormal" behaviour (tail-biting, rooting, massaging, and nibbling of pen-mates) than pigs rea...

Sanitary housing conditions modify the performance and behavioural response of weaned pigs to feed- and housing-related stressors

“…The poor sanitary conditions and the individually housed conditions may be related to a stressful environment, promoting redirected behaviours. Moreover, the housing in pens has been reported to result in a redirection of the exploratory behaviour towards the pen in individually housed piglets, or towards penmates in grouphoused piglets (Fraser et al, 1991).…”

Environmental enrichment in early life affects cortisol patterns in growing pigs

“…Enrichment of an otherwise poor environment with bedding material is believed to be a useful tool to limit stress in pigs. Straw provides several beneficial aspects due to use as a recreational stimulus, a nutritional substrate, bedding and insulation (Fraser et al, 1991).…”

“…Wood-Gush and Beilharz, 1983;Schouten, 1986;Beattie et al, 1995) and harmful social activities (Fraser et al, 1991;Arey, 1993;Beattie et al, 1995). Physiological indicators of environmental stress in pigs have, however, received relatively little attention.…”

Effects of fermentable starch and straw-enriched housing on energy partitioning of growing pigs

“…Environmental enrichment by providing 'rooting material', such as -E-mail: Liesbeth.Bolhuis@wur.nl straw bedding, strongly influences behaviour of pigs. Straw serves as an outlet for the motivation to perform foraging behaviours, such as chewing, rooting and digging, and in this way profoundly improves welfare (Fraser et al, 1991;Beattie et al, 1995;Tuyttens, 2005). The effects of straw bedding on energy partitioning in group-housed, growing pigs have not been studied so far.…”

“…Straw bedding could affect energy partitioning in different ways. Besides the influence of straw intake on energy utilisation, straw bedding may increase energy expenditure on activity, because pigs supplied with rooting material are generally more active than barren-housed pigs (Fraser et al, 1991;Beattie et al, 1995;Bolhuis et al, 2006). It is unknown whether and how these effects of straw bedding on activity and energy partitioning of pigs interact with the effects of dietary fermentable carbohydrates.…”