INFLUENCE OF DIFFERENT HANDLING METHODS AND CRATING PERIODS ON PLASMA-CORTICOSTERONE CONCENTRATIONS IN BROILERS

1. Experiments were conducted to determine whether different handling methods and crating periods differentially affect plasma corticosteron e (CS) concentrations in 6 to 7-week-old broilers. 2. Broilers were su bjected to 1 of 3 handling methods for 2 min: (i) 3 birds held in an i nverted position in one hand (multiple inverted, MI), (ii) 1 bird held in an inverted position (single inverted, SI), or (iii) upright handl ing (U), which consisted of holding a bird gently with both hands in a n upright position. 3. In experiment I birds were returned to their re spective pens after handling and in experiment 2 they were crated for up to 4 h after the imposition of handling. In experiment 2 food depri ved (FD) and fully fed (FF) uncrated birds were also sampled as contro ls. Blood samples were collected immediately after handling and at l-h intervals after handling or handling and crating. 4. In experiment 1, MI and SI birds had higher CS concentrations than U birds. 5. In expe riment 2, there were no significant differences in CS concentrations o f crated birds despite the different handling treatments. FD birds had higher mean CS concentrations than FF birds, although not as high as those of crated birds. CS concentrations peaked at 3 h after crating. Birds showed predominantly resting behaviour after crating. 6. These r esults suggest that handling stress can be reduced in broilers by the use of upright handling. However, the methods of handling is not impor tant in influencing CS concentrations if the birds are crated after ha ndling, either because crating is a more potent stressor than handling or due to stressor additivity.