Impact of group housing of pregnant sows on health

Abstract

Group housing of sows during gestation is mandatory in the EU since 2013. Compared to housing in individual crates, group housing allows the animals to express normal activity and behavior. The present paper discusses the impact of group housing on health, with emphasis on lameness, aggression and possible spread of infectious diseases. The prevalence of lameness is generally higher in sows housed in group than in sows housed individually. Floor space per sow, group size, pen design and flooring are the main factors of group housing involved in lameness development. Especially floor characteristics are important, and particular attention should be paid to the type, building material and quality of the floor, hygiene and the use of bedding such as straw or rubber mats. Aggression between sows is another critical issue in group housing systems. It occurs predominantly because of competition for access to a limited resource, or to establish a social hierarchy. Key factors to prevent aggression in group housing include gradual familiarization of unfamiliar animals, sufficient space and pen structure during initial mixing, minimizing opportunities for dominant sows to steal food from subordinates, provision of a good quality floor, environmental enrichment and use of straw bedding. Very scarce evidence-based information is available on the relationship between group housing and infectious disease. Compared to individual housing, sows in group housing have more nose-to-nose contact, and they have more oral contact with feces and urine. These factors could contribute to a higher or faster transmission of pathogens, but so far, there is no evidence showing more disease problems in group housing systems. In conclusion, in group housing systems, particular attention should be paid to prevention of lameness and aggression. Management is crucial but also feeding strategies, floor and bedding, and design of housing are very important as relatively minor adjustments may exert major effects on the animals.

Factors associated with specific health, welfare and reproductive performance indicators in pig herds from five EU countries

“…In accordance with the EU animal welfare requirements that were introduced via various EU Directives (91/630/EEC, 2001/88/EC, 2001/93/EC), group housing in sow farms became mandatory since (Maes et al, 2016). To reduce aggressiveness, lameness incidents and stress of the pregnant sows, the presence of individual resting areas in these units has been proposed with beneficial results (Verdon et al, 2015;Peltoniemi et al, 2016).…”

Review: Early life predisposing factors for biting in pigs

“…Indirectly, biting behaviour can result in injuries such as lameness due to slipping during fights (e.g. Anil et al, 2005;Maes et al, 2016) (sometimes lethal), infections due to wounds caused by biting (Schroëder- Petersen and Simonsen, 2001), immunosuppression (de Groot et al, 2001), reduced growth (e.g. Stookey and Gonyou, 1994) and, in some extreme cases, death (Sinisalo et al, 2012).…”

Sow housing associated with reproductive performance in breeding herds

“…Stall housing is commonly used in the United States during the gestation phase (McGlone, ), which can be divided into early and mid‐to‐late stages. Since 2013, group housing in European Union countries was deemed mandatory from 4 weeks after breeding to 1 week before the due date (European Commission, ), and floor space allowances in pen housing for pregnant gilts only and for sows combined with gilts, in groups of 6–40 pigs, are required to be 1.64 and 2.25 m 2 per pig, respectively (Maes, Pluym, & Peltoniemi, ).…”

“…Lame sows also have a higher risk of culling from the herds within 350 days of diagnosis (Anil, Anil, & Deen, ) and more mummified fetuses than non‐lame sows (Pluym, Van Nuffel, Van Weyenberg, & Maes, ). Therefore, prevention of lameness is critical for group housing because it severely compromise female pigs’ health (Maes et al, ) as well as subsequent longevity and lifetime performance.…”

“…European scientists warned that pregnant pigs group housed on either slatted floors or concrete floors with no bedding or in a poor‐hygiene environment tend to have more lameness than sows on solid floors with bedding or in environments with good hygiene (Maes et al, ). In a cross‐sectional study on 108 farms (Cador et al, ), concrete slat flooring was found to be a major risk factor for lameness, with a relative risk of 9.9% compared to straw bedding.…”