This study assessed the health and welfare implications of feeding pigs a dry or liquid diet when housed in either fully-slatted or straw-based accommodation. Between April and October 2002, 1024 (Large White × Landrace) × Large White pigs, housed in pens of 32, were fed ad libitum from 34 kg to slaughter at 104 kg liveweight. Data were collected on a range of welfare parameters. Feeding system affected only respiratory health losses. Lameness and tail-biting tended to be more prevalent health conditions in the fully-slatted system, while in the straw-based system pigs showed significantly more enteric and respiratory disease. There were no significant treatment effects on skin lesions or bursitis of the hock. Liquid fed pigs had poorer hygiene scores than dry fed pigs, especially in straw-based housing. Liquid feeding reduced activity level and investigatory behaviours directed towards other pigs. Pigs with straw spent a large proportion of their time manipulating it. Pigs without straw were less active and spent more time manipulating the pen hardware. In post-slaughter assessments, there were no systems differences in lung lesions or osteochondrosis, but other measures differed between housing or feeding systems; pigs with straw had more severe toe erosions on the foot, while pigs without straw had more severe heel erosions. Gastric lesions were more pronounced with dry feeding and in the fully-slatted system. The results highlight the relative health and welfare advantages and disadvantages of these systems for finishing pigs.

The nose-ringing of outdoor pigs (Sus scrofa), although commonly practiced as a means to inhibit rooting behaviour and therefore reduce pasture damage and soil erosion, has been questioned on ethical grounds and alternatives are being sought. In this experiment, the effect of overground environmental enrichment was assessed as a possible alternative. 12 multiparous sows were housed in groups of four and randomly allocated to one of three treatments in a 3 × 3 Latin square design. Treatments were: 1) no environmental enrichment, 2) edible overground enrichment in the form of grass silage, and 3) inedible overground enrichment in the form of branches and tyres. Sows that received silage as overground enrichment spent significantly less time rooting the paddock (P < 0.01) than did sows on the other two treatments. The absence of a significant difference between treatments in overall foraging time budgets suggests that the manipulation of edible substrates may substitute for rooting behaviour in outdoor sows.

The assessment of animal welfare is a complex subject which gives rise to divergent views and debate. It is generally accepted that scientific welfare assessment must involve multidisciplinary approaches, and that to interpret results unambiguously, a high level of control over the experimental conditions is required. Such considerations would appear to militate against attempts to measure welfare in a practical farm situation, where systems are relatively uncontrolled and contain many confounding factors to complicate interpretation. In consequence, fundamental welfare scientists sometimes consider that on-farm welfare assessment is of limited value. However, adherents emphasise that on-farm application is the final objective of all livestock welfare science endeavours, and also gives unique options for large-scale population studies and access to a diversity of environmental circumstances. On-farm welfare assessment not only provides an opportunity for extending knowledge on animal requirements, but is also a necessary tool in the growing requirement to assess and certify animal welfare status for legislators and consumers. However, the economic and time limitations, combined with difficulty of close access to individual animals, restrict the range and detail of possible measures. It is also essential that a consensus exists that the measurements taken are objective and meaningful to stakeholders. These constraints have tended to drive the techniques used in Farm Assurance schemes towards assessment of resource provision and management records. However, animal-based measures of health and behaviour are now being more widely explored, and the validation and standardisation of simple integrative measures for such approaches is an important future development.

A case control study with a questionnaire was carried out to compare feeding practices, diet composition, housing and management in 78 herds with or without a history of tail-biting in undocked pigs (Sus scrofa) in Finland. Tail-biting was measured as the mean annual prevalence score of tail-biting damage (TBD) for a farm. Logistic regression parameters were calculated separately for risk factors present in piglet (lactation), weaner, and finishing units. Risk factors found in piglet units for TBD were slatted floors and area of slats. In the weaner units, slatted floors, area of slats, use of whey or wheat in the diet, and use of purchased compound feeds were associated with a risk of TBD. In the finishing units, slatted floors, area of slats, increasing number of finisher pigs at the farm, absence of bedding, liquid feeding, several meals per day, specialised production type and a group size greater than nine pigs were found as risk factors for TBD. Increased farm size was connected to risk for TBD in the overall dataset. The nutritional risk factors seem to operate together with other risk factors, but with relatively lower odds. The risk factors of undocked herds in this study seem to be similar to the risk factors from earlier studies of docked pigs. This study provides information which can be used to refine decision-support tools for management of the potentially higher risk for tail-biting among long-tailed pigs, thus aiding compliance with EU law and enhancing pig welfare.

A single solution to promote higher animal welfare across the whole EU is unlikely due to significant regional differences and because what is most appropriate for each region depends on many factors. Based on analyses of eight member and candidate EU countries, this paper provides a conceptual framework, an ‘animal welfare roadmap’, which can be used to assess the stage of maturity of a country in farm animal welfare policy development and identify appropriate policy instruments and indicators to monitor progress towards higher animal welfare. The ‘roadmap’ consists of five sequential stages: increasing compliance with legislation; raising awareness; product development; mainstreaming; and integration of animal welfare with other issues. For each stage, specific policy instruments are identified alongside the category of stakeholders most likely to be influential in the implementation of each instrument. The policy instruments used to achieve these stages are those used by government departments/agencies, private enterprises, academic bodies or non-governmental organisations who formulate standards for animal welfare. These are supported by indicators best suited to document their effectiveness. Although we have emphasised how different situations and contexts within the EU mean that there is no single optimal policy instrument for the EU as a whole, but rather appropriate policy instruments should be selected according to the stage of development of a country or sector, we do propose a harmonised choice of indicators to allow benchmarking of changes at the EU level with regard to progress towards animal welfare.

Close collaboration between science and industry is essential for the formulation of evidence-based welfare policies. However, there is a need to recognise and manage potential challenges that may arise during collaborative projects. An applied animal welfare science project evaluating the inclusion of welfare outcome measures into UK pig farm assurance, with a view to industry implementation, is used as a case example to illustrate potential challenges. This project encountered difficulties associated with differences in understanding and expectations, discussion of controversial welfare issues, challenges to personal values and conflict between academic and industry outcomes. With the assistance of an independent review conducted during the project, potential solutions were developed and successfully implemented. It is proposed that similar science-industry partnerships should allow sufficient time for dialogue, distinguish between experimental and applied science, ensure sufficient involvement from interested parties and use facilitation techniques to develop consensus.

New livestock housing systems designed to improve animal welfare will only see large-scale commercial adoption if they improve profitability, or are at least cost neutral to the farm business. Economic evaluation of new system developments is therefore essential to determine their effect on cost of production and hence the extent of any market premium necessary to stimulate adoption. This paper describes such an evaluation in relation to high welfare farrowing systems for sows where any potential system needs to reconcile the behavioural needs of the sow with piglet survivability, acceptable capital and running costs, farm practicality and ease of management. In the Defra-sponsored PigSAFE project, a new farrowing system has been developed which comprises a loose, straw-bedded pen with embedded design features which promote piglet survival. Data on this and four other farrowing systems (new systems: 360° Farrower and a Danish pen; existing systems: crate and outdoor paddock) were used to populate a model of production cost taking account of both capital and running costs (feed, labour, bedding etc). Assuming equitable pig performance across all indoor farrowing systems, the model estimated a higher production cost for non-crate systems by 1.6, 1.7 and 3.5%, respectively, for 360° Farrower, Danish and PigSAFE systems on a per-sow basis. The outdoor production system had the lowest production cost. An online survey of pig producers confirmed that, whilst some producers would consider installing a non-crate system, the majority of producers remain cautious about considering alternatives to the farrowing crate. If pig performance in alternative indoor systems could be improved from the crate baseline (eg through reduced piglet mortality, improved weaning weight or sow re-breeding), then the differential cost of production could be reduced. Indeed, with further innovation by pig producers, management of alternative farrowing systems may evolve to a point where there can be improvements in both welfare and pig production. However, larger data sets of alternative systems on commercial farms will be needed to explore fully the welfare/production interface before such a relationship can be confirmed for those pig producers who will be replacing their units in the next ten years.

Increasing litter size has long been a goal of pig breeders and producers, and may have implications for pig (Sus scrofa domesticus) welfare. This paper reviews the scientific evidence on biological factors affecting sow and piglet welfare in relation to large litter size. It is concluded that, in a number of ways, large litter size is a risk factor for decreased animal welfare in pig production. Increased litter size is associated with increased piglet mortality, which is likely to be associated with significant negative animal welfare impacts. In surviving piglets, many of the causes of mortality can also occur in non-lethal forms that cause suffering. Intense teat competition may increase the likelihood that some piglets do not gain adequate access to milk, causing starvation in the short term and possibly long-term detriments to health. Also, increased litter size leads to more piglets with low birth weight which is associated with a variety of negative long-term effects. Finally, increased production pressure placed on sows bearing large litters may produce health and welfare concerns for the sow. However, possible biological approaches to mitigating health and welfare issues associated with large litters are being implemented. An important mitigation strategy is genetic selection encompassing traits that promote piglet survival, vitality and growth. Sow nutrition and the minimisation of stress during gestation could also contribute to improving outcomes in terms of piglet welfare. Awareness of the possible negative welfare consequences of large litter size in pigs should lead to further active measures being taken to mitigate the mentioned effects.

The effect of Farm Assurance (FA) assessors’ attitude to farm animal welfare on the inter-observer reliability of some welfare outcome measures achieved following training was investigated as part of a larger project examining the feasibility and benefits of the incorporation of some on-farm welfare outcome assessments into UK Pig Farm Assurance Schemes. A total of thirty-one FA assessors were trained in three training sessions to assess the following welfare outcome measures: body lesions, tail lesions, severe tail lesions, lameness and pigs requiring hospitalisation. Assessment of photographs, live observations of individual pigs and pens of pigs were used to generate inter-observer reliability data. A previously validated farm animal welfare questionnaire was used to assess the FA assessors’ attitudes to farm animal welfare. Principal Component Analysis of FA assessor scores for this questionnaire resulted in two major components, with component 1 termed ‘pigs have mental welfare’ and component 2 termed ‘people-centric, pigs as profit’. FA assessors demonstrated a range in attitudes to farm animal welfare and, when assessing the same pigs, recorded a range in prevalence of welfare outcome measures and degree of agreement with a gold standard following training. There were only seven out of a possible 98 significant correlations between the FA assessor scores for components 1 and 2 and their recorded prevalence of welfare measures and levels of agreement with a gold standard. In particular, FA assessors’ scores for component 1 were significantly positively correlated with the recorded prevalence for pigs requiring hospitalisation in two of the three training sessions although there was no effect on the agreement with a gold standard for this measure. These results indicate that training in welfare outcomes, defined by a standard protocol, is relatively unconfounded by observer attitudes to farm animal welfare. To obtain better levels of agreement between assessors, and therefore more reliable data, it is recommended that FA schemes concentrate their resources on providing good quality training in a well-defined protocol and reliability testing and that they do not need to attempt to account for the attitudes of the FA assessors to farm animal welfare.

Increasing litter size has long been a goal of pig (Sus scrofa domesticus) breeders and producers in many countries. Whilst this has economic and environmental benefits for the pig industry, there are also implications for pig welfare. Certain management interventions are used when litter size routinely exceeds the ability of individual sows to successfully rear all the piglets (ie viable piglets outnumber functional teats). Such interventions include: tooth reduction; split suckling; cross-fostering; use of nurse sow systems and early weaning, including split weaning; and use of artificial rearing systems. These practices raise welfare questions for both the piglets and sow and are described and discussed in this review. In addition, possible management approaches which might mitigate health and welfare issues associated with large litters are identified. These include early intervention to provide increased care for vulnerable neonates and improvements to farrowing accommodation to mitigate negative effects, particularly for nurse sows. An important concept is that management at all stages of the reproductive cycle, not simply in the farrowing accommodation, can impact on piglet outcomes. For example, poor stockhandling at earlier stages of the reproductive cycle can create fearful animals with increased likelihood of showing poor maternal behaviour. Benefits of good sow and litter management, including positive human-animal relationships, are discussed. Such practices apply to all production situations, not just those involving large litters. However, given that interventions for large litters involve increased handling of piglets and increased interaction with sows, there are likely to be even greater benefits for management of hyper-prolific herds.

In many countries, including the UK, the majority of domestic sows are housed in farrowing crates during the farrowing and lactation periods. Such systems raise welfare problems due to the close confinement of the sow. Despite the fact that many alternative housing systems have been developed, no commercially viable/feasible option has emerged for large scale units. Current scientific and practical knowledge of farrowing systems were reviewed in this study to identify alternative systems, their welfare and production potential. The aim was to establish acceptable trade-offs between profit and welfare within alternative farrowing systems. Linear programming (LP) was used to examine possible trade-offs and to support the design of welfare-friendly yet commercially viable alternatives. The objective of the LP was to optimise the economic performance of conventional crates, simple pens and designed pens subject to both managerial and animal welfare constraints. Quantitative values for constraints were derived from the literature. The potential effects of each welfare component on productivity were assessed by a group of animal welfare scientists and used in the model. The modelled welfare components (inputs) were extra space, substrate and temperature. Results showed that, when using piglet survival rate in the LP based on data drawn from the literature and incorporating costs of extra inputs in the model, the crates obtained the highest annual net margin and the designed pens and the pens were in second and third place, respectively. The designed pens and the pens were able to improve their annual net margin once alternative reference points, following expert-derived production functions, were used to adjust piglet survival rates in response to extra space, extra substrate and modified pen heating. The non-crate systems then provided higher welfare and higher net margin for sows and piglets than crates, implying the possibility of a win-win situation.

In this study, pig producers were identified whose practices exceeded the basic legal requirements and government recommendations for pig welfare. This novel approach was part of a larger project investigating the feasibility and benefits of the inclusion of some animal-based welfare outcome measures into the main UK pig-farm assurance schemes. A set of pig-keeping-system descriptor scores were devised through consultation with stakeholders, whereby a finishing pig farm would be classified on a scale of 1 (legislation compliance) to 5 (highest level of welfare provision) for six different elements of pig husbandry which can influence pig welfare (environmental enrichment, foraging behaviour, thermal comfort, physical comfort, tail docking and floor space provision). Animal-based observations were used to assess the welfare of a sample of between 67 and 220 pigs on 15 UK finishing pig farms, which were also classified according to the system descriptors. Scores achieved when assessing the environmental enrichment and physical comfort elements were significantly positively correlated with a qualitative assessment of good mood of the pigs and a measure of their oral manipulation and significantly negatively correlated with the prevalence of tail lesions and swollen bursae. However, there were wide variations in the prevalence of animal-based welfare outcome measures between farms with the same system descriptor score. These system descriptors are therefore not sufficient to be used alone to provide assurances on welfare. It is suggested that a combined approach of system descriptors and animal-based welfare outcome measures may be useful for providing assurances on higher levels of welfare.

In commercial pig production, piglets are often mixed after weaning which can result in severe aggression and lead to body damage, disruption of feeding behaviour and reduced growth. This experiment investigated whether application of a synthetic maternal pheromone to groups of weaned pigs in commercial housing would affect the level of aggression and skin lesions sustained after mixing. Two treatments (Pheromone and Control) were used with 16 replicate pens of pigs (20 pigs per pen). Treatments were applied on the day of weaning (average 28 days of age) on a per room basis in alternate weeks. In Pheromone pens, after routine washing and disinfection, the walls and feeders were treated one hour prior to occupation with a synthetic pheromone at a rate of 1.0 ml pig−1. Control pens were as for Pheromone except no product was applied. During the 24-h period, post mixing, pigs in pheromone-treated pens spent significantly less time fighting than those in control pens. This was reflected in reduced injury scores 24 h after mixing, with pigs in pheromone-treated pens having 39% fewer skin lesions on the front of the body compared to those in control pens. Treatment had no effect on growth rate or feed efficiency, although the feed intake for days 7–28 was significantly lower and feed efficiency tended to be lower in pheromone-treated pens. In conclusion, application of a synthetic maternal pheromone can be considered one of the arsenal of strategies to reduce aggression and safeguard the welfare of groups of weaned pigs where mixing is unavoidable.

The Welfare Quality® project aims to develop a European on-farm welfare assessment standard for pigs, amongst other species. A prototype monitoring system was developed for sows and piglets using predominantly animal-based measures of behaviour, health and physiology to assess welfare. The prototype monitoring system was evaluated on a total of 82 farms in the UK and The Netherlands, encompassing a wide variety of farming systems. Preliminary analysis of the data indicates that the incidence of clinical welfare problems were low, with 1.2, 0.8, 1.1 and 0.1%, respectively of pregnant and lactating sows recorded as having substantial skin lesions, bursitis and vulval lesions, and extremely poor body condition. Some clinical problems were more prevalent in certain types of feeding system than others, particularly the severity of vulval lesions with electronic sow feeding (ESF) systems. Fear of humans, assessed by the extent of withdrawal behaviour from an unknown human, was low, and median scores were similar for sows housed in groups indoors, outdoors and in stalls. Some form of stereotyped behaviour was observed on almost 75% of farms visited, with sham chewing the most commonly recorded stereotyped behaviour. System design affected the practicality of some measures, particularly on outdoor farms. Full investigation of the complete data set will enable a refined, final, on-farm monitoring system to be developed and benchmark standards established.

Reproductive performance of gilts/sows can be influenced by metabolic state at crucial points in the reproductive cycle and indeed at a crucial age. It has generally been found that moderate to severe protein restriction has no effect on litter size or embryo survival at day 28 (Pharazyn et al, 1991) when given to gilts over the gestation period. However protein quality and quantity can affect reproductive performance in gilts when imposed over the prepubertal period as indicated previously by lower ovulation rate at an induced puberty and poorer expression of a second oestrus (Cia et al, 1996). In the present experiment the effects of two diets differing in lysine:energy ratio on body composition and subsequent oestrus response, ovulation rate and early embryo development in gilts of two different ages were studied.