Locomotion Disorders and Skin and Claw Lesions in Gestating Sows Housed in Dynamic versus Static Groups

September Locomotion Disorders and Skin and Claw Lesions in Gestating Sows Housed in Dynamic versus Static Groups Emilie-Julie Bos 0 1 Dominiek Maes 1 Miriam M. J. van Riet 0 1 Sam Millet 0 1 Bart Ampe 0 1 Geert P. J. Janssens 1 Frank A. M. Tuyttens 0 1 0 Institute for Agricultural and Fisheries Research (ILVO), Animal Sciences Unit , Scheldeweg 68. 9090 Melle , Belgium , 2 Ghent University, Faculty of Veterinary Medicine, Department of Reproduction , Obstetrics and herd health, Salisburylaan 133, 9820 Merelbeke , Belgium , 3 Ghent University, Faculty of Veterinary Medicine, Department of Nutrition , Genetics and Ethology, Heidestraat 19, 9820 Merelbeke , Belgium 1 Editor: Dan Weary, University of British Columbia , CANADA Lameness and lesions to the skin and claws of sows in group housing are commonly occurring indicators of reduced welfare. Typically, these problems are more common in group housing than in individual housing systems. Group management type (dynamic versus static) and stage of gestation influence the behavior of the animals, which in turn influences the occurrence of these problems. The present study compared prevalence, incidence and mean scores of lameness and skin and claw lesions in static versus dynamic group housed sows at different stages of gestation during three consecutive reproductive cycles. A total of 10 Belgian sow herds were monitored; 5 in which dynamic groups and 5 in which static groups were utilized. All sows were visually assessed for lameness and skin lesions three times per cycle and the claws of the hind limbs were assessed once per cycle. Lameness and claw lesions were assessed using visual analogue scales. Static groups, in comparison with dynamic groups, demonstrated lower lameness scores (P<0.05) and decreased skin lesion prevalence (24.9 vs. 47.3%, P<0.05) at the end of gestation. There was no difference between treatment group regarding claw lesion prevalence with 75.5% of sows demonstrating claw lesions regardless of group management. Prevalences of lameness (22.4 vs. 8.9%, P<0.05) and skin lesions (46.6 vs. 4.4%, P<0.05) were highest during the grouphoused phase compared to the individually housed phases. Although the prevalence of lameness and skin lesions did not differ three days after grouping versus at the end of the group-housing phase, their incidence peaked during the first three days after moving from the insemination stalls to the group. In conclusion, the first three days after grouping was the most risky period for lameness incidence, but there was no significant difference between static or dynamic group management. - OPEN ACCESS Data Availability Statement: All relevant data are within the paper and its Supporting Information files. Funding: This study was funded by the Institute for Promotion of Innovation through Science and Technology in Flanders, Belgium (IWT, Grant Number 090938) and co-funded by Orffa, VDV Beton, Boerenbond, AVEVE, INVE, and Boehringer Ingelheim. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Introduction Since January 2013, all sows in the European Union must be group-housed from four weeks after service to one week before parturition (European Directive 2001/88/EC). Group housing allows for social contact and interactions between sows [1;2]. Moreover increased activity of group housed sows as compared to individually housed sows, has a positive effect on muscle and bone development [3;4]. However, the positive benefits to group housing of sows may also be accompanied by factors that negatively impact sow welfare. Depending on the feeding system, more feeding competition may occur, and aggression towards other sows increases, resulting in an increased risk for skin lesions, vulva biting, claw problems and lameness [1;5;6]. In commercial settings, sows will not only be housed in groups, but will also experience different types of housing through gestation including insemination and farrowing crates. Gestating sows are often housed in larger groups than feral pigs, with (somewhat to completely) unfamiliar animals and these group compositions are usually changed at least once per reproductive cycle [ 7 ]. When housing sows in groups, many aspects need to be considered, including group size, group density, pen design, floor type, bedding material, feeding system and group management (dynamic versus static) [ 8 ]. Commercial sow groups can be managed as either a static or a dynamic group. In static groups the group composition stays the same after formation, so only one breeding group is present per pen. sows experience one bout of mixing, and the associated aggression, at the beginning of gestation. If a sow recycles or is removed for some reason, no replacement sow is introduced. In dynamic groups, animals are introduced into and removed from the group throughout the gestating period, with the number of introductions and removals depen (...truncated)