Can we measure chronic stress in broilers?

Leonie Jacobs - Commercial housing conditions may contribute to chronic negative stress in broiler chickens, reducing their animal welfare. 

The aim of this study was to examine the impact of environmental complexity and stocking density on the levels of immunoglobulin-A (IgA) in fast-growing broiler chickens. IgA might provide insights in the chronic stress experienced.
IgA levels decrease when the body is subjected to physiological or physical stress. On the other hand, these levels increase when individuals have positive experiences.

This study revealed that broiler chickens housed in complex environments exhibited higher concentrations of plasma IgA, suggesting a lower level of chronic stress compared to those in simpler environments. Moreover, birds raised in low-density environments displayed increased concentrations of secretory IgA, indicating reduced chronic stress compared to birds in high-density environments. These results demonstrate that the concentrations of plasma and secretory IgA in broiler chickens are influenced by their housing conditions. It is worth noting that these measures effectively differentiate levels of chronic stress when statistical power is high. However, further research is required to validate these outcomes under similar and diverse conditions before these measures can be widely adopted for assessing chronic stress in broiler chickens.

You can read the study here

Campbell, A.M., Anderson, M.G., Jacobs, L. Measuring Chronic Stress in Broiler Chickens: Effects of Environmental Complexity and Stocking Density on Immunoglobulin-A Levels. Animals 2023, 13, 2058. https://doi.org/10.3390/ani13132058 

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