Changes in blood catecholamine levels in neonatal and growing lambs

Area of Science:

• Animal Physiology
• Endocrinology
• Neonatal Metabolism

Background:

• Catecholamines, including adrenaline (A) and noradrenaline (NA), play crucial roles in physiological adaptation.
• Free fatty acid (FFA) metabolism is vital for energy supply, particularly in neonates.
• Understanding developmental changes in these parameters is essential for assessing lamb health and stress responses.

Purpose of the Study:

• To investigate the developmental trajectories of plasma catecholamine (A and NA) and FFA concentrations in lambs from birth to 6 months of age.
• To assess the impact of physiological transitions, such as suckling and weaning, on these metabolic markers.
• To determine any potential correlations between catecholamine and FFA levels during lamb growth.

Main Methods:

• Longitudinal study design tracking 12 lambs from birth to 6 months.
• Regular blood sampling to measure plasma concentrations of adrenaline, noradrenaline, and FFA.
• Analysis of hormonal and metabolic changes in response to developmental stages and weaning stress.

Main Results:

• Plasma A, NA, and FFA levels were highest at birth and decreased by 6 months.
• A transient increase in plasma A and decrease in NA occurred within the first 3 days, returning to baseline by day 10 post-suckling, coinciding with an FFA decline.
• Noradrenaline stabilized at a higher level up to 100 days, increasing total catecholamines and the NA/A ratio; weaning induced a significant rise in catecholamines and FFA, with no observed relationship between them.

Conclusions:

• Lamb plasma catecholamine and FFA levels exhibit dynamic changes during early development, influenced by suckling and weaning.
• Noradrenaline plays a significant role in maintaining elevated catecholamine levels in later stages of early life.
• Weaning represents a notable physiological stressor impacting both catecholamine and FFA dynamics in lambs.