Hair cortisol and dehydroepiandrosterone sulfate concentrations in healthy beef calves from birth to 6 months of age

Cortisol (C) and dehydroepiandrosterone (DHEA) are recognized as the main fetal steroids, they likely to influence development have long-term effects on newborn hypothalamic-pituitary-adrenal axis (HPA) function. DHEA is often measured its sulfates expressed DHEA-S. Hair analysis represents a promising methodological approach for non-invasive measurement of allowing retrospective total exposure steroids over time, avoiding acute events or circadian fluctuations. cortisol concentrations been investigated in cows, but no studies performed calves. The object this study was evaluate hair (HC) DHEA-S (HDHEA-S) beef calves from birth six months age. samples 12 (seven males, five females) were firstly collected at (T1) then every three weeks up age (T2-T10), collecting only re-grown hair. HC HDHEA-S analyzed by radioimmunoassay (RIA). Calves sex, weight APGAR score registered immediately after birth. Statistical revealed that both influenced sampling time (P < 0.001). higher T1 compared all subsequent samplings (T2-T10, P 0.01); T2 T4-T10 0.01), while further changes detected T3 onward. Higher T1, other 0.01). No correlation found between calf sex birthweight. negatively correlated with 0.05). These data demonstrate C quantifiable their probably reflects high serum present late pregnancy increased HPA axis, which parturition initiated cows. highest indicates largest amounts produced during development. Moreover, findings until birth, suggest secretion continues also beyond these could be involved occurring challenging first calf.