Preweaning diet and stall weaning method influences on stress response in foals.

The research focuses on how different preweaning diets and stall weaning methods can affect the stress responses in foals during their weaning period.

Introduction and Methodology

• The research examined the effects of weaning stress on the behaviour and physiological status of foals. The parameters considered for stress measurement were behavioural protocol, plasma ascorbate levels, serum cortisol levels, and the serum cortisol response to an Artificial Corticotropic Hormone (ACTH) challenge.
• To comprehend this, a 2 x 2 factorial experimental plan was designed using two preweaning diets and two stall weaning methods.
• The two preweaning diets were: foals raised on a pasture which was supplemented with hay and a pelleted concentrate (PHC) and the second, foals raised on pasture supplemented with only hay (PH).
• Furthermore, the foals were either placed singly or in pairs during the stall weaning process. Potential influences of foal’s sex were also took into consideration.

Findings

• Foals demonstrated typical behavioural and physiological responses to weaning stress.
• The study revealed fewer outward signs of stress in foals weaned individually than those weaned in pairs.
• Trends indicated fewer signs of stress exhibited by foals on the PHC diet as compared to the ones on the PH diet, suggesting that supplementation with concentrate might help in better stress management.
• The plasma ascorbate concentrations, however, did not show a noticeable difference among the treatment groups.
• Interestingly, the serum cortisol response to ACTH challenge was lower in PH diet fed foals and in paired foals, suggesting adrenal depletion due to stress. This implies that these subsets experienced higher stress.
• A positive correlation was found between behaviour scores and serum cortisol response to the ACTH challenge, reinforcing that these are valid measures of stress.

Conclusion

• Both behavioural and ACTH response data suggested that foals might cope better with the weaning process when they are supplemented with concentrate before weaning and when they are placed in stalls individually rather than in pairs.