Relationship between plasma cortisol and stereotypic activities in pigs.

Area of Science:

• Animal Behavior
• Animal Physiology
• Stress Endocrinology

Background:

• Stereotypic behaviors are common in intensively farmed animals, often linked to poor welfare.
• The physiological underpinnings, particularly the relationship with stress hormones like cortisol, require further investigation.

Purpose of the Study:

• To investigate the relationship between stereotypic behaviors (chain manipulation, drinking) and plasma cortisol levels in chronically restrained sows.
• To determine if preventing stereotypic behaviors affects plasma cortisol concentrations.

Main Methods:

• Sows were classified as high or low stereotypers based on chain manipulation and drinking behaviors.
• Plasma cortisol levels were measured.
• Chain and nipple drinkers were removed to assess the impact on behavior and cortisol levels.
• Automatic logging systems recorded detailed behavioral data.

Main Results:

• No significant difference in plasma cortisol levels was found between high and low stereotypers.
• Removal of chains and nipple drinkers did not alter cortisol concentrations.
• Chain manipulation was not correlated with plasma cortisol levels, even after removal.
• Drinking behavior showed a tendency towards a negative correlation with cortisol levels.

Conclusions:

• Chain manipulation in chronically restrained sows does not appear to reduce plasma cortisol levels.
• The observed relationship between drinking and cortisol may be a physiological consequence of water intake rather than a coping mechanism.