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The impact of gestation housing system (Individual vs. Group) on the reproductive performance of sows
The objective of the study was to evaluate the effect of gestation sow housing system on sow performance under commercial conditions. The study was carried out on a commercial breed-to-wean facility using a RCBD to compare 2 treatments, Individual vs. Group (8 females/pen) housing. Sows on the Individual treatment were housed in gestation stalls (dimensions 0.54 m x 2.07 m; floor space 1.12 m²/female). The Group housing was created in the same building by combining 8 stalls by removing the backs and part of the side divisions of the stall. Pens dimensions were 2.20 m x 4.71 m, providing a total floor space of 1.30 m²/female. A replicate was 16 females (8 in 1 Group and 8 Individually-housed); a total of 1325 pregnant females were allotted to treatments in 106 replicates at approximately 35 d post-mating after pregnancy checking. Sows on both treatments were housed in individual stalls from weaning to d 35 of gestation. Management of females in pregnancy and lactation was in line with standard commercial practice. Data were available for 955 females that completed a first parity and 370 females that completed first and second parity. The experimental unit was the individual sow and data were analyzed using PROC MIXED of SAS; the model included the fixed effects of treatment and parity and the random effect of replicate. There was no effect (P > 0.05) of treatment on number of piglets born (alive, dead, mummified, total), piglet and litter weights (birth, weaning), weaning to rebreeding interval, or female BW and body condition. However, females housed in Groups had lower (P < 0.05) farrowing rate (3.9 % units) and higher (P < 0.05) sow removal rate (5.7 % units), and piglet pre-weaning mortality (1.2 % units) than those housed in individual stalls. This study suggests that housing first and second parity females in groups in pens converted from gestation stalls can have a negative effect on reproductive performance.
Keywords: sow, gestation, group housing, stalls