Tail biting is a common problem in intensive pig farming, affecting both welfare and production. Although routine tail docking is banned within the EU, it remains a common practice to prevent tail biting. Straw as environmental enrichment has been proposed as an alternative to tail docking, but its effectiveness against tail biting and function in manure handling systems have to be considered. The aim of the study was to survey how pigs with intact tails are raised and how tail biting is handled in Sweden, where tail docking is banned through national legislation. The study emphasises straw usage and its association with tail biting pigs and problems in the manure handling system. The expectation is that this information could be conveyed to the rest of the EU to reduce the need for tail docking. In a telephone survey of randomly selected Swedish pig farmers (46 nursery and 43 finishing pig units) with at least 50 sows or 300 finishing places, it was found that straw was used by 98% of the farmers. The median daily straw ration provided was 29 g/pig for nursery and 50 g/pig for finishing pigs in systems with partly slatted flooring. The reported prevalence of tail biting was 1.6% at slaughter. The majority of farmers reported that they never had manure handling problems caused by straw (56% of nursery units and 81% of finishing pig units). A proportion of farmers (37%) also provided with additional material apart from straw on some occasions, which may have affected tail biting prevalence and manure handling problems. Swedish farmers rear undocked pigs without large problems with tail biting. Straw is the main manipulable material used, and additional manipulable material is used to various extents. The low incidence of straw obstructing the manure handling systems implies that it is indeed possible to use straw in partly slatted flooring systems, reducing the need for tail docking. The impact of using additional manipulable material is unknown and requires more investigation to separate the impact of such material from the impact of straw.

Tail posture (i.e., hanging or curled) has been suggested to be an indicator of tail biting, and hanging tails predisposed to damage. The aim of this study was to investigate if tail posture was feasible as a tail damage indicator in a commercial setting. The study was carried out on one batch of 459 undocked finishing pigs (30–120 kg in weight). Weekly scoring of tail posture was combined with the scoring of tail lesions. Tail posture was observed at feeding to facilitate the usage of the method in commercial settings. A curly tail was observed in 94% of the observations. Pigs with tails scored with “wound” were 4.15 (p < 0.0001) times more likely to have hanging tails, and pigs scored with “inflamed wounds” were 14.24 (p < 0.0001) times more likely to have hanging tails, compared to pigs with nondamaged tails. Tail posture correctly classified tails with “wound” or “inflamed wound” 67.5% of the time, with 55.2% sensitivity and 79.7% specificity, respectively. The method of observing the tail position at feeding seems useful as a complement to normal inspection for detecting tail biting before tail wounds are visible to the caretaker.

Tail biting is a common issue within commercial pig production. It is mainly an indicator of inadequate housing environment and results in reduced health welfare and production. To reduce the impact of tail biting, pigs are commonly tail docked, without pain relief, within the first week of life. EU Council Directive 2008/120/EC prohibits routine tail docking, but the practice is still widely used in many Member States. Sweden has banned tail docking since 1988 and all pigs have intact tails, yet tail biting is a minor problem. This paper summarises and synthesises experimental findings and practical expertise in production of undocked pigs in Sweden and describes solutions to facilitate a transition to producing pigs with intact tails within intensive pig production in the EU. Swedish pig housing conditions and management differ in many aspects from those in other EU Member States. Swedish experiences show that lower stocking density, provision of sufficient feeding space, no fully slatted flooring, strict maximum levels for noxious gases and regular provision of litter material are crucial for success when rearing pigs with intact tails. To prevent tail biting and to eliminate the need for tail docking, we strongly recommend that EU legislation should more clearly match the biological needs of pigs, as is done in Swedish legislation.

We systematically mapped the scientific literature on the sustainability of pig production at farm-level. Sustainability was considered holistically, covering its economic, environmental, and social dimensions, each consisting of a broad range of different aspects that may contradict or reinforce each other. Literature published between January 2000 and March 2020 with a geographical focus on Europe, North America, Australia, and New Zealand was included. A standard template with predefined keywords was used to summarise aspects of each sustainability dimension covered in identified papers. We found that papers analysing environmental sustainability were more frequent than papers analysing economic or social sustainability. However, there are many different aspects within each dimension of sustainability, hampering comparisons between studies. In addition, each dimension of sustainability has many sides, making it difficult to compare different studies, and different dimensions and aspects may have complex interrelations. Our systematic literature review revealed that these interrelations are not well understood and that possible trade-offs or synergies between different aspects of sustainability dimensions remain unidentified. This systematic mapping of the current literature on farm-level sustainability in pig production can support a more informed discussion on knowledge gaps and help prioritise future research at farm-level to enhance sustainability in pig production.

Unfulfilled exploratory behavior in pigs has been linked to tail biting, which causes reduced performance and welfare. Provision of straw can reduce tail biting, but large straw rations can cause poor hygiene in pens. This study examined whether provision of straw in racks, rather than on the pen floor, can enable larger straw rations without compromising hygiene. The study was conducted on a commercial farm with 458 undocked pigs in 42 pens provided with straw in racks or on the floor. Available straw and manual cleaning requirement were assessed daily, and presence of tail lesions was assessed weekly. Both treatments had a low requirement for manual cleaning (Floor: 1.7%, Rack: 1.8%). Pigs in the rack treatment had a higher incidence of lesions early in the production period, which coincided with these pigs initially not consuming straw from the rack, leading to low straw access. Late in the production period, these pigs had learned how to use the rack and had a lower incidence of lesions than pigs in the floor treatment. Delayed use of the rack may have been linked to undeveloped spatial skills in the pigs, which needs further research.