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A complex environment makes chicks stress tolerant

Last changed: 18 May 2021

Exposure to stress early in life can affect birds kept in commercial production systems in ways which alter the development of different morphological, immunological and behavioural indicators. Researchers from the Swedish University of Agricultural Sciences, in collaboration with several international partner institutes, have studied if a complex environment during early life better prepares birds to cope with stressful events as well as buffers them against future unpredictable stressful episodes.

In this study, 96 one day old pullets were randomly distributed to two groups, where one was assigned to a Simple Environment, and the other to a Complex Environment. Half of the birds from each group were assigned to either a No Stress or to an acute Cold Stress treatment on their second day of life. At four weeks of age, chicks with these four different backgrounds were exposed to an Intermittent Stressful Challenges Protocol. Immunological tests showed that the immune competence in birds reared in a Complex Environment were least affected by the stress tests, maybe because they rested more and thus recovered better than birds from the Simple Environment. Cold-stressed birds had lower humoral immune responses after the stress tests, and started their use of elevated structures later in the Complex Environment. These results reflect the importance of a complex rearing environment to reduce negative stress-related effects. Within the context of the theory of adaptive plasticity, our results suggest that the early experience of the birds had long lasting effects on the modulation of their phenotypes.

Link to publication

doi.org/10.1371/journal.pone.0210270

Reference

Campderrich, I., Nazar, F.N., Wichman, A., Marin, R.H., Estevez, I., Keeling, L.J. (2019) Environmental complexity: A buffer against stress in the domestic chick. PLoS ONE 14(1): e0210270.