In a study in Japan two cows were dosed by capsule with either 40 or 400 mg tebufenozide bw day for 7 days (Inoue, 1993). From the average weight of the cows, these doses correspond to 0.074 and 0.74 mg/kg per day. Milk was collected on days 1, 3, 5, and 7. Milk samples were injected onto a C-18 Sep-Pak and the fraction containing tebufenozide was concentrated and analysed on a TSK-gel ODS-80 HPLC column eluted with acetonitrile/water (7:3) with UV detection at 254 nm. The limit of determination was 0.02 mg/kg. There were no detectable residues in any of the milk samples.
It was reported that a feeding study was in progress in the USA in which groups of four cows had been dosed with the equivalent of 0, 6, 18, and 60 ppm of tebufenozide in the diet. Residues of tebufenozide and the main metabolites identified in the goat metabolism study were being determined in the milk, liver, muscle, kidney and fat.
No poultry feeding study was reported. Most of the crops for which registration of tebufenozide has been approved or is expected do not produce feed components for poultry. An exception is cotton, from which cotton seed meal can be used, but no data from this crop were provided.
