Although often described as “welfare-friendly”, the greater freedom of movement and choice of environments offered by communal farrowing systems does have potential welfare risks, primarily for the piglets. The maternal qualities of the sow will have a greater influence on the survival and growth of piglets in this communal farrowing system, than in a conventional farrowing crate and may be influenced by genotype. The objectives of this study were to compare the welfare of sows and piglets housed in farrowing crates and a communal farrowing system and to investigate whether sow genotype influences the quantity and quality of maternal behaviour and subsequent litter performance.

The objectives of this study were to establish what changes in posture by sows carried a high risk of piglet crushing in a group farrowing system during early lactation and also to determine what factors influenced the risk of crushing during lying down. A total lf 24 Large White x Landrace sows were studied during the first 7 days of lactation in a group farrowing system. Cross-fostering was not carried out so as not to influence behaviour. Dead piglets were removed and cause of death ascertained from external observation and post-mortem examination. Sow and piglet behaviour was video-recorded continuously. A total of 268 piglets were born alive, with 67 liveborn piglets subsequently dying during the 7-day experimental period, 50 as a result of crushing. A total of 7425 posture changes were analysed and 11 types of posture change were identified, the most dangerous being lying down from standing and those involving swapping sides, or rolling over, whilst lying.Dangerous events during lying down were more likely to occur (1) in the first 24 h after farrowing, (2) when the sow lay down in the middle of the pen, (3) when the sow lay down without carrying out much piglet-directed pre-lying behaviour and (4) when the piglets were spread out but near to the sow. the amount of pre-lying behaviour decreased over time and crushing mortality also decreased. The results confirm that he piglets are most vulnerable to crushing during the first 24 h of life, when they are spending much of their time near the udder and have relatively poor mobility. co-ordination of behaviour between the sow and her litter is important to reduce the risk of crushing. It is also important that the design of open farrowing systems incorporates knowledge about how crushing deaths occur in order to improve piglet welfare.

Comparative data on housing systems may facilitate the producer's ability to choose, but are often confounded by farm effects. The present study aimed to provide information on production and labour input, as well as indicators of health and welfare in three different finishing pig systems, on one farm. The three systems were a Sloping Floor (S), a Kennelled (K) and a Part-slatted (P) system. Average Daily Gains tended to be different between housing systems (e.g. Summer data: 862, 885 and 844 g day(-1), for S, K and P respectively, F-2,F-17=2.94; P=0.080). Food intakes showed corresponding differences, such that Food Conversion Ratio did not differ. The percentage of rejections for health reasons in K was nearly half that of S and P (1.9, 3.9 and 3.6% respectively) but the difference was not significant (chi (2)=0.679; P>0.05). The number of skin lesions was greater in S compared to P, with K intermediate. However, this may have been confounded by pig cleanliness. The incidence of stomachs with lesions and / or parakeratosis did not differ significantly. Systems S and K required an average of 175 and 283 kg straw pig place(-1) year(-1). Significantly more electricity was required to run P compared to the other systems (e.g. Summer: 0.07, 0.06 and 17.1 kWh week(-1) for S, K and P respectively; F-5.54=893.5; P<0.001). However, P required the least labour input per pig place (e.g. Summer: 2.1, 2.4 and 0.9 min pig place(-1) week(-1) for S, K and P respectively). It was concluded that pig performance was similar for the three systems, and that health and welfare parameters are influenced differently by the various elements that make up housing systems. Overall running costs were highest for the part slatted system during the Summer, but during the Winter period they did not differ.

As a part of a study investigating the extent to which ad libitum feeding of a high fibre diet could mitigate behavioural problems associated with food restriction, the performance of sows given food at restricted or ad libitum levels was compared. Ten subgroups of five were allocated to each of the restricted (R) and ad libitum (A) feeding regimes. Five weeks after service, subgroups were introduced into one of two dynamic groups of sows housed in adjacent straw-bedded pens. R sows received a fixed daily ration (parity 1: 2.2 kg; parity 2: 2.4 kg) of a conventional pregnancy diet (13.1 MJ digestible energy per kg)from an electronic sow feeder. Sows on the A regime had unrestricted access to five single-space hoppers dispensing a high fibre diet (containing 600 g unmolassed sugar beet pulp per kg). Subgroups were maintained on these gestation feeding regimes for two consecutive parities. During both parities, A sows were heavier by day 50 of gestation (parity 1: P < 0.05; parity 2: P < 0.01) and at farrowing (parity 1: P < 0.001; parity 2: P < 0.001) than R sows. No difference was found between feeding regime in sow weight at weaning, due to a greater weight loss during lactation of A (parity 1: P < 0.001; parity 2: P < 0.001) than R sows. No difference was found between feeding regime in sow backfat thickness, sow reproductive performance or litter performance in either parity. This suggests that unmolassed sugar beet pulp diets may be used to feed sows on an ad libitum basis during gestation without compromising productivity. However, food intakes may be too high (estimated at 4.1 kg per sow per day) to make ad libitum feeding of pregnant sows an attractive option for producers.

The causes and timing of piglet mortality were studied in different farrowing systems. In the first experiment 198 litters were recorded in three systems, two of which allowed the sows to move freely, and the third restricted them in conventional crates. More piglets were weaned from the conventional crates than from the open systems and they grew more quickly. More than half the liveborn mortality occurred during the first four days after parturition. In the open systems, 17 per cent and 14 per cent of the piglets born alive were crushed, compared with only 8 per cent in the crates. In the second experiment, 29 sows and litters were studied in detail in a communal pen system during the first seven days of lactation. Three-quarters of the liveborn mortality was due to crushing. The total number of piglets dying per litter, including stillbirths, was significantly associated with the total litter size and the sow's parity. The percentage liveborn mortality was significantly associated with the parity and body length of the sows and with the within-litter variation in the birth weight of the piglets. Individual birth weight was closely associated with percentage survival. Only 28 per cent of piglets weighing less than 1.1 kg at birth survived to seven days.

This study examines the interactive effects of mixing and the provision of kennels to finishing pigs on agonistic behaviour. Pigs were housed either in naturally ventilated kennelled accommodation, or in an unkennelled sloping floor accommodation with automatically controlled natural ventilation (ACNV). Under each of these two housing conditions, three groups of 10 pigs were subjected to one of the following four mixing/moving treatments: no mixing (control), mixing and moving at 55 kg only, mixing and moving at 75 kg only and mixing and moving on both occasions. Groups which were not mixed at 55 kg or at 75 kg were moved to a novel pen at the time that the others were mixed. Mixing and moving pigs resulted in higher levels of aggression and skin damage compared to moving only. Levels of skin lesions were lower when mixing at 55 kg compared to mixing at 75 kg. The duration and frequency of fights in the immediate post mixing period and skin damage measured on day 1 after mixing correlated well when mixing pigs at 75 kg, but not when mixing at 55 kg. This suggests that the hierarchy takes longer to be established in younger pigs than it does in older heavier pigs, or that skin damage inflicted by heavier pigs during fights is more severe. Previous mixing at 55 kg had minimal effects on mixing at 75 kg in terms of behaviour immediately post mixing and skin lesions in the following two days. The presence of a kennel appeared to have a positive effect on the average duration of fights, but the effect on the proportion of fights which involved location changes (lying to dunging area or vice versa) was not significant. Performance data suggested that food conversion ratios were poorer in the first two weeks after mixing in the kennelled building, but not in the sloping floor building. Increased social and thermal stress after mixing in the kennelled, naturally ventilated accommodation may have been the cause of this. Over the whole of the finishing period, daily live weight gains and food conversion ratios did not differ measurably between treatments.

EU Council Directive 91/630/EEC specifies a banded system of increasing space allowance for finishing pigs, which imposes a degree of inflexibility on housing management. The study presented in this paper investigated whether there are measurable differences in welfare when pigs are kept at the minimum stocking densities described by the bands of the regulations (B), compared to those calculated using an equation (E) relating space allowance and live weight; Area (m2)=0.030×Live weight0.67 (kg). Furthermore, the study compared different floor types [fully slatted (F), solid without straw (N) or solid with straw bedding (S)] at these stocking densities. Eighteen groups of 12 pigs were allocated to this 2×3 factorial experiment, between 29 and 110 kg live weight. Data were collected on a range of welfare parameters. No effects of the space allowance treatments or interactive effects between space allowance and floor type were found. S pigs showed higher levels of manipulative behaviours than N pigs (47 vs. 57% of time spent active, N vs. S; P<0.01), with S pigs manipulating straw approximately 45% of active time. Observed skin damage was less in N pigs compared to S pigs, but this may have been confounded by their pens being more soiled (59 vs. 77% clean floor area, N vs. S; P<0.001). Post slaughter assessments did not show differences between treatments. It was concluded that straw provision may provide welfare benefits in terms of pen cleanliness and its properties as a foraging substrate. The results indicated that the equation method of specifying minimum space requirements, which offers practical advantages compared with the banded method, provides a similar degree of welfare. This conclusion may help to form the basis for future European welfare legislation.

The farrowing crate was designed to make sow management easier, allow higher stocking densities and reduce piglet mortality. Recently, concerns about sow welfare within farrowing crates have lead to a reappraisal of open farrowing systems. However, more freedom of movement for the sow places greater influence on the quality of maternal care, if piglet welfare is to be safeguarded. The aims of this study were to compare the behaviour of gilts housed in different farrowing systems and to determine any differences in behaviour, that may affect piglet survival.After service, 38 LW x Landrace gilts (PIC, Abingdon, UK) were formed into groups of 3-5 and were assigned to either farrowing crates or a communal farrowing system. Each crate room housed six conventional crates with sow feeders, nipple drinkers and forward piglet creeps. Each pen room contained five individual strawed pens (2.7m x 1.9m) with a rectangular piglet creep at the rear, sloping walls along both sides and piglet and sow drinkers.

In group feeding systems, competition over access to food may be heightened by food restriction, as hungry sows remain active and motivated to feed. The behavioural effects of food restriction may be mitigated by satisfying feeding motivation more effectively or by providing sows with a substrate with which to express their foraging behaviour. Twenty groups of seven multiparous sows were used in a 2×2 factorial design to investigate the effects on behaviour of floor feeding sows the same daily weight of iso-energetic conventional (C) or high fibre (H; containing 600 g of unmolassed sugar beet pulp per kilogram of diet) pregnancy diets in strawed (S) or un-strawed (N) pens. Observations were conducted from the start of feeding for 2 h (0900–1100 h) and for 2 h in the afternoon (1300–1500 h). Sows on S treatments received more aggressive interactions (P<0.01) and were displaced from the feeding area more frequently (P<0.001) than sows on N treatments. S sows also spent more time standing during the feeding period (P<0.001) than N sows, which appeared to account for the difference in the level of aggression observed. No improvement was found, in overall levels of aggression, in feeding sows the H diet, although damage to the vulva was significantly lower in H (P<0.05) than C-fed sows. The presence of straw in the pen reduced the level of pen component manipulation and non-manipulative oral behaviours, during both observation periods. H-fed sows spent less time manipulating substrates during the afternoon observation period (P<0.05) than C-fed sows, due to an increase in the time spent inactive (P<0.05). While feeding sows in un-strawed pens may limit aggression in competitive feeding systems, providing sows with access to straw may reduce excessive levels of pen-directed behaviours. Feeding sows diets which are high in dietary fibre may reduce behaviours associated with a lack of satisfaction of feeding motivation, suggesting that there may be welfare benefits associated with feeding sows high fibre diets, although not necessarily in competitive feeding systems.

An abstract is not available for this content so a preview has been provided. As you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Compared with small groups, housing in large groups offers the pig more total available space, resulting potentially in an increased degree of control over its (micro) environment. For the producer, large groups require fewer pen divisions and offer more possibilities for the sharing of resources such as feeders and drinkers. However, whilst large groups may offer benefits to higher ranking animals in the group, there may be serious disadvantages for those further down the social hierarchy, who also need to compete for access to resources. This study investigated the interactive effects on welfare of food availability (one single space hopper per 20 or per 10 pigs) and group size (20, 40 or 80 pigs per pen), at constant stocking density (0.55 m(2) per pig) in part-slatted pens. Groups provided with two feeding spaces per 20 pigs were less active than,groups with one feeding space per 20 pigs. The number of aggressive interactions per pig at the food trough was not affected by group size but decreased with number of feeder spaces per 20 pigs. The number of skin lesions increased with group size. Average daily gain in the first half of the finishing period was negatively influenced by group size and positively by number of feeding spaces. No effect on weight gain was found subsequently. Within-group variation in growth was not affected by group size or number of feeder spaces. No differences between treatments were found in the number of pigs removed for health reasons. Interactive effects of the two treatments were found on some behaviours but not on any of the performance variables measured. It is concluded that, from a welfare point of view, the number of pigs per feeder spare should be lower than 20, although performance levels appear acceptable at 20 pigs per feeder. Further research will have to identify whether the effects of group size on general aggression is common to all finishing pig systems, or whether the presence of straw can serve as a mitigating factor.

The Codes of Recommendation for the Welfare of Livestock (pigs) recommends “Pigs should be kept in stable groups with as little mixing as possible”. In practice, mixing can not always be avoided, particularly towards the end of the finishing period. The present study investigated welfare aspects of mixing finishing pigs in two different types of accommodation.A total of 240 finishing pigs (weight: 29.0 kg, SD=2.6 kg), housed in groups of ten, were subjected to a 2 x 4 factorial designed study. The factors were housing (two treatments) and mixing / moving (four treatments). The mixing treatments were applied at 55 and 75 kg average group weight, by either mixing half the group with half the pigs from another group in a pen unknown to both groups (MIX), or moving the pigs to a new pen (MOVE). The four mixing treatments therefore were: A (control). MOVE at 55 and 75 kg, B: MIX at 55 and MOVE at 75 kg, C: MOVE at 55 and MIX at 75 kg and D: MIX at 55 and 75 kg. The housing treatments were: scrape-through dunging area with strawed kennel (KEN) and strawed sloping floor without kennel (NO). Agonistic behaviour was recorded during the first two hours after MIX or MOVE, of four focal pigs in each group.

The inability of sows to appropriately express feeding motivation has been identified as one of the major contributory factors in the development of stereotypic behaviour. It has been proposed that the development of these repetitive behaviours may be mitigated either by reducing feeding motivation, for example by feeding sows bulky diets which increase gut fill, or by providing sows with a foraging substrate. Forty-eight nulliparous sows were used in a 2×2 factorial design comparing the interactive effects of a high fibre diet and the provision of straw on the behaviour of food restricted pregnant sows. Sows were fed the same daily weight of iso-energetic conventional (C) or high fibre (H; containing 600 g of unmolassed sugar beet pulp per kg of food) diets during gestation and were housed in pens with straw (S) or without straw (N). Behaviour was recorded by direct observation and video during their second gestation. Levels of chain and bar-directed behaviour were highest in the hour immediately following food presentation. Although no difference was found in activity levels or levels of chain and bar manipulation between dietary treatments, sows fed the high fibre diet spent less time manipulating straw (C vs. H; 46.3 vs. 37.0%, P<0.05) than sows fed the conventional diet, after adjustment for the time spent feeding (C vs. H; 20.0 vs. 29.4%, P<0.001). In addition, increasing dietary fibre tended to reduce the level of manipulation of substrates other than straw, but only in the final hour of observation. This suggests that fermentation of sugar beet pulp may play a role in maintaining levels of satiety later in the day, when the satiety levels of conventionally fed sows are starting to decline. The provision of straw significantly reduced levels of chains and bar manipulation (S vs. N; 14.4 vs. 35.3%, P<0.01), and levels of non-manipulative oral behaviour (S vs. N; 0.4 vs. 3.8%, P<0.05). Although the daily provision of fresh straw may provide a reliable way of reducing pen component manipulation and the development of stereotypic behaviour, it is unclear to what extent welfare is improved by exchanging excessive pen component manipulation with the excessive manipulation of straw.

In competitive feeding systems in which sows are group rather than individually fed, aggression can arise as sows compete for limited supplies of food (Csermely and Wood-Gush, 1990). Aggression may also occur as a result of sows’ motivation to feed remaining unsatisfied due to restricted access to food (Buré, 1991). Feeding sows a high fibre diet which will rapidly increase gastric distention (Brouns et al., 1997) may reduce both the motivation to compete for food and aggression associated with sustained feeding motivation. Sows provided with straw bedding may use straw as a foraging substrate with which to express their foraging behaviour. The aim of this experiment was to investigate the interactive effects of a high fibre diet and straw bedding on levels of aggression in floor fed sows.

Previous work has identified crushing to be the major cause of early piglet mortality (up to 80%) in a group farrowing system, with approximately half of the crushing deaths occurring when the sow lay down from a standing position (Marchant et al., 1996). The objectives of this study were to establish what other posture changes carried a high risk of piglet injury in a communal farrowing system during early lactation and also to determine what factors influenced the risk of piglet crushing during lying down.

The Welfare of Livestock Regulations 1994 specify a system of increasing space allowance for finishing pigs based on a series of weight bands (Figure 1). The width of the bands in the regulations, especially at the higher weights, impose a certain degree of inflexibility on the management of finishing pig accommodation. An alternative approach to specifying space allowance is to relate it to average pig live weight at any given time using an allometric equation (Petherick and Baxter, 1981). Based on this, Edwards et al. (1988) proposed A(m2)=0.030*M0.67(kg), to optimise performance on slats. The present study compares space allowance increments following this equation with the bands of the regulations, and its interactive effects with floor type and bedding on the welfare of finishing pigs.

Food restriction appears to be a contributory factor in the development of stereotypic behaviour in sows. The sustained feeding motivation following the ingestion of a small meal of concentrated food results in high levels of foraging in the post-prandial period. In the absence of a suitable foraging substrate to facilitate the expression of complex behaviours, foraging may be channelled into a limited number of highly repetitive behavioural sequences (Lawrence and Terlouw 1993). High fibre diets may mitigate the development of such behaviours (Brouns, Edwards and English 1994) by providing increased gut fill in the post-prandial period, thereby reducing foraging motivation and consequently the need for a foraging substrate. The aim of this study was to examine the interactive effects of a high fibre diet and the provision of straw on levels of stereotypic behaviour in sows.

With the advent of the stall and tether ban in the UK it is now a requirement to house dry sows in groups throughout their pregnancy which necessitates their being mixed with other sows at some point after service. It is generally recommended that mixing sows during the embryo implantation period should be avoided as this is thought to effect embryo survival rates. The object of this experiment was to demonstrate the aggression that occurs between sows after mixing and determine the effect on reproductive performance when mixing sows at different times during the 42 days post-service.294 sows were mixed at six different times during early pregnancy: 0 to 7(T1), 8 to 14,(T2) 15 to 21(T3), 22 to 28(T4), 29 to 35(T5) and 36 to 42(T6) days post service. Six groups of sows from six consecutive weeks weanings were served at the first post-weaning oestrus and kept in stable weekly treatment groups until the sixth group was served.

Community lactating systems offer a number of potential welfare benefits to the sow and her litter. However, giving the sow greater freedom of movement and choice of environments also has potential risks. With less restriction, the maternal qualities of the sow will have a greater influence on the survival and growth of her litter. The objectives of this experiment were to determine what behaviours of the sow influenced piglet mortality in an open communal farrowing system

Ad libitum feeding of a high fibre diet may be instrumental in reducing the development of abnormal behaviours in group housed sows (Brouns et al.1994). However, although there may be welfare benefits associated with feeding sows in this way, such a feeding practice is unlikely to be adopted unless it is commercially viable. This study compared the reproductive performance of gilts fed a high fibre diet ad libitum throughout gestation, with gilts fed a commercial diet on a restricted level.