title: Diurnal variation of plasma testosterone in wild stallions.
mesh_terms: D000818:Animals; D002940:Circadian Rhythm; D006736:Horses / Q000097:blood*; D008297:Male; D009009:Montana; D012726:Sexual Behavior, Animal; D013045:Species Specificity; D013739:Testosterone / Q000097:blood*
chemical_list: D013739:Testosterone