Effects of bis(tri-n-butyltin)oxide in Japanese quail exposed during egg laying period: An interlaboratory comparison study

The guideline no. 206 for testing of chemicals of the Organization for Economic Cooperation and Development (OECD) comprising an avian reproduction test using the Japanese quail (Coturnix coturnix japonica; Termminck and Schlegel 1849) as pair-hold test organisms has been applied in a version that reduced the treatment period to 6 weeks without any pretreatment. In the present study bis(tri-n-butyltin)oxide, C.A. No. 56-35-9 (tributyltin oxide, TBTO) was examined by five participants in an interlaboratory comparison test. A comparable regimen of dosing was performed by all participants starting either with 24 or 60 mg/kg TBTO in the feed and ending with 150 or 375 mg/kg. Within this dose range no signs of toxicity in adults were observed. Substance-related effects however were obvious with regard to egg production, fertility, hatching success, and survival of 14 day-old chicks. A clear dose dependency was given regarding effects on egg weight and on hatchability. The no-observed-effect concentrations for these two parameters was 60 mg/kg TBTO, characterizing these parameters as the most sensitive in this investigation. With the presented set of test parameters further aspects of subchronic toxicity in adults and chicks can be assessed as well as the validity of the performed test. Comparing the results for most test parameters consistency is obvious, thus confirming the applicability of the presented test guideline.