Plasma corticoid changes during diarrhea in neonatal calves

Area of Science:

• Veterinary Medicine
• Endocrinology
• Neonatal Calf Health

Background:

• Neonatal calf diarrhea is a significant cause of mortality.
• Diarrhea leads to severe fluid and electrolyte imbalances.
• The adrenal cortex's response to such stress in calves is not fully understood.

Purpose of the Study:

• To investigate the adrenal cortex's response to experimentally induced diarrhea in neonatal dairy calves.
• To compare plasma corticoid levels between healthy, diarrheic, and treated calves.

Main Methods:

• Experimentally induced acute diarrhea in 11 neonatal dairy calves using a viral inoculum.
• Administered fluid and electrolyte therapy to some affected calves.
• Measured plasma corticoid levels (aldosterone, hydrocortisone, progesterone, corticosterone) using radio-immunoassay and competitive protein-binding assay.

Main Results:

• Significantly elevated plasma aldosterone levels were observed in non-surviving diarrheic calves before death.
• Higher plasma hydrocortisone and progesterone were noted in untreated diarrheic calves prior to death.
• Increased plasma corticosterone was observed throughout the disease in recovering calves.

Conclusions:

• The adrenal cortex of neonatal calves demonstrates a responsive capacity to the physiological stress of diarrhea.
• Fluid-electrolyte loss and stress associated with calf diarrhea influence key adrenal steroid hormones.
• These findings highlight the role of the adrenal cortex in the stress response during neonatal calf diarrhea.