Neoformation of boldenone and related steroids in faeces of veal calves

Conflicting findings regarding the boldenone content of bovine faeces suggest it may be synthesized de novo in emitted faeces. We tested this hypothesis by analysing uncontaminated urine, fresh and various forms of dried faeces from 10 calves (not given boldenone) by liquid chromatography/tandem mass spectrometry for 17(alpha)- and 17(beta)-boldenone ((alpha) and (beta) BOL); 1,4-androstadiene-3,17-dione (ADD); 4-androstene-3,17-dione (AED), testosterone (T) and epitestosterone (ET). Urine contained no (alpha) BOL, (beta) BOL or ADD. The analysed substances were variably present in the rectal faeces, and at generally higher levels in faeces scraped from skin or stall floor. In pooled rectal faeces naturally dried for 13 days, a BOL, ADD, AED and ET levels were extremely high (much higher than accounted for by increases due to drying), and (beta) BOL and T were absent. It is concluded that de novo synthesis of (alpha) BOL and metabolites occurs naturally in bovine faeces and only uncontaminated urine should be analysed for illegal boldenone.