The concentrations of cortisol in the incubation medium mimic plasma cortisol levels seen in fish exposed to different types of stresses such as handling, confinement, high density, food-deprivation or air-exposure.
After weaning, all the lambs were individually exposed to 4 standardized behavioral tests combining social isolation, exposure to humans or handling, confinement and novelty (i.e. arena test, corridor test, isolation box test, shearing test).
In addition, the effect of handling and confinement on CORT levels was measured.
Finally, fish were subjected to a handling and confinement stress routinely used for rainbow trout stress response research [ 15, 43- 46].
Preliminary procedures (handling, loading, confinement and unloading) were undertaken by the same staff and blood sampling was always carried out by the same operator.
Handling and confinement has been investigated to ensure the well-being of the fish in our previous studies (Mothersill et al. 2009, 2007, 2006).
2012b), these gene expression patterns could indicate that the temperature stressor, in combination with handling and confinement stresses, resulted in a relatively more stressful holding period for the pink salmon.
Progeny of gilthead sea bream (Sparus aurata) from parents selected for low- or high-cortisol response also show divergent responses [ 10], although in this species low-cortisol responders can be more sensitive to handling and confinement [ 11].
To date, most studies have estimated the animal variation in CH4 production, either by using the traditional chamber technique or SF6 techniques, where handling and confinement of the animals is required.
In the case of gilthead sea bream, endocrine and metabolic responses to handling and confinement exposure have been analyzed in some detail [ 10, 33- 36], but this is the first attempt at an extensive transcriptional study to monitor the dynamics of the stress response.
