Nest building and farrowing in sows: relation to the reaction pattern during stress farrowing environment and experience

Nest building and farrowing behaviour of 40 Landrace/Yorkshire (L/Y) sows was studied in their first and second parity. In the first parity the gilts were either housed in a crate or a "get-away-pen" (GAP) and in the second parity either the same farrowing environment was used again or the sow was housed in the alternative system. The behaviour was compared with the behavioural reaction pattern of the same individuals in prepubertal tests (open field test, human-test, food competition test) and the reactivity in the HPA-axis during the open field test. Nest building behaviour was in both parities found to be more elaborated in the GAPs, where the prepartum rooting period started significantly sooner (32.5 +/- 3.0 h versus 41.3 +/- 3.0 h, F-1,F-27 = 5.72; P < 0.05 and 27.4 +/- 3.3 h versus 35.6 +/- 3.1 h, F-1,F-27 = 4.33; P < 0.05, respectively) and had a longer duration (21.5 +/- 3.1 h versus 32.6 +/- 3.1 h, F-1,F-27 = 8.33; P < 0.01 and 27.9 +/- 3.6 versus 38.7 +/- 3.4 h, F-1,F-27 = 6.57; P < 0.05, respectively). Farrowing behaviour was in the first parity strongly dependent upon the environment, e.g. the mean piglet birth interval was significantly longer in the crates (30 +/- 14 min versus 19 +/- 3 min, F-1,F-21 = 5.55; P < 0.05), indicating an increased environmental sensitivity in gilts as compared to the second parity sows, where no environmental effect was found. Both farrowing and nest building behaviour, especially in the first parity, was connected to the prepubertal behavioural and physiological reaction pattern (1st parity-immobility in human-test similar to activity during farrowing: r(s) = -0.49; P < 0.01, N = 38 and the quantity of postural changes in nest building period similar to rise in cortisol during open field test: r(s) = 0.44; P < 0.01, N = 35). Furthermore, there was a strong repeatability across parities in parameters describing activity during nest building and farrowing. The prepubertal gilts reacting behaviourally calm in a stressful situation were timing their nest building more optimally than the more actively responding individuals. Behavioural activity during prepubertal tests was also correlated with being active during farrowing. We therefore conclude that behaviour during nest building and farrowing is related to the general reaction pattern during stress, especially in inexperienced gilts, and that the performance reflects an innate pattern of reaction in the individual, that can be modified by the environment and previous experience. (C) 2002 Elsevier Science B.V. All rights reserved.