Welfare and performance of sows and piglets in farrowing pens with temporary crating system on a Spanish commercial farm

The study aimed to compare the welfare and performance of sows and piglets in three different farrowing systems (farrowing crate (FC) and farrowing pen with temporary crating (TC): SWAP and JLF15). One batch of crossbred Duroc was followed in every season. There were 18 sows (183 piglets) in FC, 23 sows (243 piglets) in SWAP, and 23 sows (237 piglets) in JLF15. Farrowing day was Day (D) 0 and weaning occurred on D24. Crating period was from entry to weaning in FC, and from 1-day pre-expected farrowing day to D3 in TC. Social interactions between littermates, between sows and piglets, and exploration by sows and piglets were observed on D2, D4, D12, and D23. Video recordings of crushing events which led to piglets' death were studied. Piglets were weighed on D3 and D19, and foreleg abrasions were assessed on D19. Sow saliva samples were collected on 1 day before and after temporary confinement, D2, D4, D12, and D23 to evaluate cortisol (CORT) and chromogranin A (CgA) levels. TC piglets initiated naso-naso contacts with sows more frequently than FC on D2 (P <= 0.01). TC sows interacted with piglets more frequently than FC on D12 (P <= 0.05). TC sows explored the pens more frequently than FC on D4 (P <= 0.05). Crushing rate (i.e. number of piglets per sow) of SWAP (1.2 +/- 0.3) was higher than those of JLF15 (0.6 +/- 0.2) and FC (0.3 +/- 0.1) (P < 0.02), and crushing rate of JLF15 was higher than that of FC (P < 0.0001). Autumn batch showed the lowest crushing rate amongst different batches (P < 0.001). Number of crushing incidents was similar when TC sows were crated or loose (P = 0.54). The percentage of occasions when sows used a support from the pen when changing posture but still crushed the piglets was higher in FC than in TC (P = 0.05). No difference of growth and foreleg abrasion in piglets were found between systems. CORT in SWAP peaked on D2 (P = 0.02), and CgA in JLF15 peaked on D4 and remained elevated on D12 (P <= 0.05). CORT and CgA in FC remained similar during lactation. Our results suggested that TC facilitated mother young interactions; TC showed a higher crushing rate; sows changed their posture differently between systems and batches; the practice of temporary crating did not alter the level of stress biomarkers in sows.