ARS | Publication request: The Effect of Alleyway Width on Gestating Sow Welfare in a Free-Access Stall System

Submitted to: Journal of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: March 1, 2010
Publication Date: July 11, 2010
Citation: Mack, L.A., Elischer, M.F., Eicher, S.D., Johnson, A.K., Lay Jr, D.C., Richert, B.T., Pajor, E.A. 2010. The Effect of Alleyway Width on Gestating Sow Welfare in a Free-Access Stall System [abstract]. Journal of Animal Science. 88:T4(E-Suppl. 2).

Technical Abstract: Free-access stalls allow sows to choose the protection of a stall or use of a shared alleyway. This study investigated the effect of the alleyway width on production and physiological parameters in gestating sows. At approximately d 30 of gestation, 8 replicates of 21 pregnant sows (n=168) were equally assigned to 3 pens each comprising 7 free-access stalls and a shared alleyway of either 0.91m, 2.13m, or 3.05m where they remained until farrowing. Basal measures of all parameters were taken before the sows were mixed. Back fat (BF), BW, BCS, and lameness (LM) were measured on d 35, 65, and 101 after pen assignment. Sows were lesion scored weekly. Blood samples were taken on d 30, 66, and 100. Data were analyzed in SAS using a mixed model with a post-hoc Tukey adjustment. Although similar initially, the overall BF was greater in the 0.91m sows than the 2.13m (P < 0.05) and increased in all groups over time (P < 0.05). Weight increased over time (P < 0.0001) but did not differ by treatment. BCS showed no overall treatment or time differences, but on d 35 the 0.91m sows had a higher BCS than the 3.05m sows (P < 0.05). Lameness increased slightly in the 2.13m and 3.05m sows after mixing and decreased steadily afterward in the 3.05m sows (P < 0.05). Upper body lesions increased after mixing and then decreased in all treatments (P < 0.0001). Lower leg and hoof lesions showed no differences by treatment or time. Cortisol increased after mixing and then decreased (P < 0.01), but no treatment difference was observed. The percentage of neutrophils was greater (P < 0.05) and the neutrophil: lymphocyte ratio, indicating stress, tended to be higher (P < 0.10) in the 0.91m sows than the 3.05m sows. Neither the percentage of monocytes nor lymphocytes differed by time or treatment. The differences between treatments were slight, but, overall, the data suggest reduced welfare, especially near the end of gestation, in the 0.91m alleyway due to space restrictions.