Effects of dietary fibre on behaviour and satiety in pigs

During the past decades there has been considerable interest in the use of dietary fibre in both animal and human nutrition. In human subjects dietary fibre has been studied intensively for possible effects on body-weight management and health. In animal nutrition the interest in dietary fibre has increased because it can be used as a cheap source of energy and because of its potential to improve animal welfare and reduce abnormal (mainly stereotypic) behaviour. Animal welfare is impaired if the diet does not provide sufficient satiety, combined with an environment that does not meet specific behavioural requirements related to natural feeding habits (e.g. rooting in pigs). A considerable proportion of the behavioural effects of dietary fibre are thought to be related to reduced feeding motivation. It has been hypothesized that: (1) bulky fibres increase satiety and thereby decrease physical activity and stereotypic behaviours immediately following a meal in pigs; (2) fermentable fibres prolong postprandial satiety and thereby reduce physical activity and appetitive behaviours for many hours after a meal. The validity of these hypotheses is examined by considering published data. In sows dietary fibres (irrespective of source) reduce stereotypic self-directed behaviours and substrate-directed behaviours, and to a lesser extent overall physical activity, indicating enhanced satiety shortly after a meal. Furthermore, fermentable dietary fibre reduces substrate-directed behaviour in sows and physical activity in sows and growing pigs for many hours after a meal. Evidence of long-term effects of poorly-fermentable fibre sources is inconclusive. The findings suggest that highly-fermentable dietary fibres have a higher potential to prolong postprandial satiet

Vertrouwde geur geeft minder stress bij spenen

Varkens hechten zeer aan geur: de aroma’s die de ongeboren biggen al in de baarmoeder ‘opsnuiven’, hebben lange tijd een gunstig e…ffect op het dier. Bijvoorbeeld na het spenen. Biggen die dan de vertrouwde aroma’s kunnen ruiken, hebben daardoor minder stress. Dit blijkt uit onderzoek van Marije Oostindjer en Liesbeth Bolhuis, onderzoekers van de Leerstoelgroep Adaptatiefysiologie van Wageningen UR

Big wil hetzelfde brokje als zijn moeder

In de praktijk wordt veel geëxperimenteerd met geurige en lichtverteerbare biggenvoeders, aantrekkelijke voerbakjes en de inrichting van het kraamhok. Alles om de jonge big maar vlot aan het vreten te krijgen, zodat het dier het spenen straks goed doorstaat. Recent onderzoek van de Leerstoelgroep Adaptatiefysiologie van Wageningen UR toont aan dat de jonge big niet zit te wachten op een leuk bakje met een uitgekiende 'jongelingenmix'. De big wil gewoon hetzelfde brokje als zijn moeder. Hier kan handig gebruik van worden gemaakt om biggen te leren eten

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

Both dietary fermentable carbohydrates and the availability of straw bedding potentially affect activity patterns and energy utilisation in pigs. The present study aimed to investigate the combined effects of straw bedding and fermentable carbohydrates (native potato starch) on energy partitioning in growing pigs. In a 2 × 2 factorial arrangement, 16 groups of 12 pigs (approximately 25 kg) were assigned to either barren housing or housing on straw bedding, and to native or pregelatinised potato starch included in the diet. Pigs were fed at approximately 2.5 times maintenance. Nitrogen and energy balances were measured per group during a 7-day experimental period, which was preceded by a 30-day adaptation period. Heat production and physical activity were measured during 9-min intervals. The availability of straw bedding increased both metabolisable energy (ME) intake and total heat production (P <0.001). Housing conditions did not affect total energy retention, but pigs on straw bedding retained more energy as protein (P <0.01) and less as fat (P <0.05) than barren-housed pigs. Average daily gain (P <0.001), ME intake (P <0.001) and energy retention (P <0.01) were lower in pigs on the native potato starch diet compared to those on the pregelatinised potato starch diet. Pigs on the pregelatinised potato starch diet showed larger fluctuations in heat production and respiration quotient over the 24-h cycle than pigs on the native potato starch diet, and a higher activity-related energy expenditure. The effect of dietary starch type on activity-related heat production depended, however, on housing type (P <0.05). In barren housing, activity-related heat production was less affected by starch type (16.1% and 13.7% of total heat production on the pregelatinised and native potato starch diet, respectively) than in straw-enriched housing (21.1% and 15.0% of the total heat production on the pregelatinised and native potato starch diet, respectively). In conclusion, the present study shows that the availability both of straw bedding and of dietary starch type, fermentable or digestible, affects energy utilisation and physical activity of pigs. The effects of housing condition on protein and fat deposition suggest that environmental enrichment with long straw may result in leaner pigs. The lower energy expenditure on the physical activity of pigs on the native potato starch diet, which was the most obvious in straw-housed pigs, likely reflects a decrease in foraging behaviour related to a more gradual supply of energy from fermentation processes

Effects of loose housing and the provision of alternative nesting material on peri-partum sow behaviour and piglet survival

Sows are strongly motivated to perform nestbuilding behaviour before parturition. This behaviour is often restricted in commercial systems due to confinement of the sow and lack of suitable nesting material to be used on slatted floors. This study aimed to investigate effects of loose vs. crated housing and the provision of alternative nesting material on periparturient sow behaviour and piglet survival. In a 2 × 2 arrangement, sixty-eight sows were assigned to either loose housing or crates and were either or not provided with nesting material consisting of jute sacks and straw balls. All sows had a rope. Postures and manipulation of materials and pen were observed using 5 min scan sampling for the 12 h before and the 24 h after parturition. Behaviour during parturition was scored continuously and included nose-nose contact between sow and piglets and crushing incidences. No interactions between treatments were found. In the 12 h prepartum, loose housed sows showed less sitting (5 vs. 9%) and ventral lying (29 vs. 38%) and more lateral lying (33 vs. 23%) and floor manipulation (10 vs. 5%) than crated sows. During parturition, loose housed sows spent less time sitting (2 vs. 6%), had fewer postural changes (34 vs. 50), showed less fence manipulation (0.1 vs. 2%) and had more nose contact with piglets (56 vs. 19 times). Provision of nesting material increased pre-partum lying (63 vs. 57%), increased manipulation of materials (14 vs. 8%) and reduced manipulation of floor (5 vs. 10%) and fence (5 vs. 9%). During parturition, sows with nesting material showed less standing (6 vs. 10%) and more lying (90 vs. 84%). No effects were found on behaviour in the 24 h after parturition or on parturition duration (3.3 ± 0.1 h). During parturition, the times lying down and the number of piglets that died by crushing tended to be lower with provision of nesting material (0.1 vs. 0.3). In the 48 h after parturition, loose housed sows crushed more piglets. In conclusion, both loose housing and the provision of alternative nesting materials affected prepartum sow behaviour and resulted in less activity during parturition, with some tendencies for beneficial effects on (near-) crushing of piglets during this period. Thus, both loose housing and the provision of alternative nesting materials, likely particularly the jute sacks, have a beneficial effect on periparturient sow behaviour

Emotions on the loose: emotional contagion and the role of oxytocin in pigs

We studied emotional contagion, a simple form of empathy, and the role of oxytocin herein in pigs. Two training pigs per pen (n = 16 pens) were subjected to a positive treatment (pairwise access to a large compartment filled with peat, straw and some chocolate raisins) and a negative treatment (social isolation in a small compartment) in a test room using a within-subjects design. Thereafter, two naive pen mates joined the training pigs in the test room, but were not given access to the treatments. This allowed testing for emotional contagion. Subsequently, the naive pigs, serving as their own controls, were given 24 IU of oxytocin or a placebo intranasally 30 min before accompanying the training pigs, which were exposed to either the negative or positive treatment, to the test room. Behavioral differences found between the positive and negative treatments (e.g., play and “tail wagging” vs. standing alert, urinating, defecating and ears backward) show that the treatments induced a positive and negative emotional state in the training pigs, respectively. Changes in behaviors of the training pigs with and without naive pigs present (e.g., in ears backwards) and of the naive pigs with and without training pigs present (e.g., in standing alert) indicated that emotional contagion occurred, especially during the negative treatment. Oxytocin did not seem to affect the behavior of the treated naive pigs, but did affect behaviors (e.g., defecating) of the training pigs which had not received oxytocin. This suggests a role for oxytocin in pig communication, which merits further research

Tail Biting in Pigs: Blood Serotonin and Fearfulness as Pieces of the Puzzle?

Tail biting in pigs is a widespread problem in intensive pig farming. The tendency to develop this damaging behaviour has been suggested to relate to serotonergic functioning and personality characteristics of pigs. We investigated whether tail biting in pigs can be associated with blood serotonin and with their behavioural and physiological responses to novelty. Pigs (n = 480) were born in conventional farrowing pens and after weaning at four weeks of age they were either housed barren (B) or in straw-enriched (E) pens. Individual pigs were exposed to a back test and novel environment test before weaning, and after weaning to a novel object (i.e. bucket) test in an unfamiliar arena. A Principal Component Analysis on behaviours during the tests and salivary cortisol (novel object test only) revealed five factors for both housing systems, labeled ‘Early life exploration’, ‘Near bucket’, ‘Cortisol’, ‘Vocalizations & standing alert’, and ‘Back test activity’. Blood samples were taken at 8, 9 and 22 weeks of age to determine blood platelet serotonin. In different phases of life, pigs were classified as tail biter/non-tail biter based on tail biting behaviour, and as victim/non-victim based on tail wounds. A combination of both classifications resulted in four pig types: biters, victims, biter/victims, and neutrals. Generally, only in phases of life during which pigs were classified as tail biters, they seemed to have lower blood platelet serotonin storage and higher blood platelet uptake velocities. Victims also seemed to have lower blood serotonin storage. Additionally, in B housing, tail biters seemed to consistently have lower scores of the factor ‘Near bucket’, possibly indicating a higher fearfulness in tail biters. Further research is needed to elucidate the nature of the relationship between peripheral 5-HT, fearfulness and tail biting, and to develop successful strategies and interventions to prevent and reduce tail biting

Aggression and Affiliation during Social Conflict in Pigs

Social conflict is mostly studied in relation to aggression. A more integral approach, including aggressive and affiliative behaviour as well as physiology, may however give a better understanding of the animals' experience during social conflict. The experience of social conflict may also be reflected in the spatial distribution between conspecifics. The objective was to assess the relationship between behaviour, physiology, and spatial integration in pigs (Sus scrofa) during social conflict. Hereto, 64 groups of pigs (9 wk of age) were studied in a 24 h regrouping test whereby pairs of familiar pigs were grouped with 2 unfamiliar pairs, in either barren or straw-enriched housing. Data on aggressive and affiliative behaviour, skin lesions, body weight, and haptoglobin could be summarized into three principal component analysis factors. These three factors were analysed in relation to spatial integration, i.e. inter-individual distances and lying in body contact. Pigs stayed up to 24 h after encounter in closer proximity to the familiar pig than to unfamiliar pigs. Pigs with a high factor 1 score were more inactive, gave little social nosing, had many skin lesions and a high body weight. They tended to space further away from the familiar pig (b = 1.9 cm; P = 0.08) and unfamiliar ones (b = 0.7 cm; P = 0.05). Pigs that were involved in much aggression (factor 2), and that had a strong increase in haptoglobin (factor 3), tended to be relatively most far away from unfamiliar pigs (b = 0.03 times further; P = 0.08). Results on lying in body contact were coherent with results on distances. Pigs in enriched housing spaced further apart than pigs in barren housing (