Shorter nursing duration and more nursing terminations by the sow were observed in loose housing than in farrowing crates.
Sows confined to farrowing crates are restricted in performing natural behaviour such as maternal behaviour. Loose-housing farrowing pens and farrowing pens with crates were compared regarding sows’ nursing behaviour via video analyses over four weeks per batch (one day per week).
Nursing frequency was similar in loose-housing farrowing pens and farrowing pens with crates (1.25 ± 0.82 vs. 1.19 ± 0.75 nursings/sow/hour). However, nursing duration differed between the two systems (loose housing: 5.7 ± 4.6 min vs. farrowing crates: 7.0 ± 5.0 min). In loose housing pens, more nursing bouts were sow-terminated than in farrowing pens with crates. The probability of sow-terminated nursing occurring increased from week 1 to week 4, while that of observing unnursed piglets decreased from week 1 to week 4 and rose with increasing litter size.
We conclude that nursing behaviour was affected by the farrowing system, with shorter nursing duration and more nursing terminations by the sow in loose housing than in farrowing crates. Since this corresponds to the nursing behaviour of sows in semi-natural conditions, it can be assumed that sows in loose housing pens are more likely to exhibit natural nursing behaviour.