Consequences for Piglet Performance of Group Housing Lactating Sows at One, Two, or Three Weeks Post-Farrowing.

Housing lactating sows with piglets in a multi-suckling pen from around 14 days post-farrowing is common practice in Swedish organic piglet production. However, nursing-suckling interaction is less frequent in multi-suckling pens than in individual farrowing pens, thus affecting piglet performance, e.g., piglet growth. Moreover, piglet mortality is higher in systems using multi-suckling pens. Three management routines whereby lactating sows with piglets were moved from individual farrowing pens to multi-suckling pens at one, two, or three weeks post-farrowing were compared in terms of nursing-suckling interaction and piglet performance. Correlations between nursing-suckling interaction, piglet performance, and piglet mortality were also examined. In total, 43 Yorkshire sows with piglets were included in the study. Nursing-suckling interaction and all piglet performance parameters except piglet mortality did not differ between management routines. Piglet mortality in the individual farrowing pens did not differ between management routines, but piglet mortality in the multi-suckling pen was lower (P<0.05) when piglets were group housed at three weeks compared with one week post-farrowing. Overall piglet mortality was positively correlated with mortality in the multi-suckling pen for piglets group housed at one week (r = 0.61: P<0.05) and at two weeks post-farrowing (r = 0.62: P<0.05) but not for piglets group housed at three weeks post-farrowing. In conclusion, overall piglet mortality could be reduced if sows and piglets are group housed at three weeks post-farrowing and piglet survival the first week post-farrowing is improved.