Steroid precursors, steroids, neuroactive steroids, and neurosteroids concentrations in serum and saliva of healthy neonatal heifer Holstein calves.

Abstract

BACKGROUND: Persistence of high neurosteroid concentrations in blood is associated with neonatal encephalopathy and septicemia in foals. This has not been investigated in calves. OBJECTIVES: To determine concentrations of steroid compounds in serum and saliva within the first 48&#x2009;hours after birth in healthy neonatal calves, identify potential markers for disease, and investigate the association between serum steroid compounds concentrations in calves and their respective dams within 2 hours after birth. ANIMALS: Twelve healthy neonatal heifer Holstein calves and their dams. METHODS: Prospective study. Serum and saliva were collected from calves at 2, 6, 24, and 48&#x2009;hours after birth. Steroid compounds were analyzed using liquid chromatography-mass spectrometry. A nonlinear regression model was used to determine half-lives of the neurosteroids. Serum concentrations of neurosteroids between the cows and calves were compared using the Wilcoxon signed rank test. RESULTS: Half-lives (95% confidence intervals) of dehydroepiandrosterone (DHEA) and 17&#x3b1;,20&#x3b1;-dihydroxyprogesterone in calf serum were 2.9 (2.1, 4.3), and 2.1 (1.3, 3.0) hours, respectively. Pregnanediol in saliva had a half-life (95% confidence interval) of 24.5 (14.2, 66.5) hours. Serum DHEA (1718.7 &#xb1;&#x2009;2313 vs 57.7 &#xb1;&#x2009;44) and 17&#x3b1;,20&#x3b1;-dihydroxyprogesterone (207.8 &#xb1;&#x2009;198.2 vs 43.5 &#xb1;&#x2009;33.5) concentrations respectively were higher (P <&#x2009;.05) in calves compared to cows. CONCLUSIONS AND CLINICAL IMPORTANCE: Dehydroepiandrosterone, 17&#x3b1;,20&#x3b1;-dihydroxyprogesterone, and pregnanediol could be potential markers of disease in neonatal heifer calves with unexplained failure to thrive or encephalopathy. However, because of the wide 95% confidence interval of the half-life, pregnanediol in saliva might not be a potential marker.