Repeated oral dose of monocrotophos in goats: its bioaccumulation

Monocrotophos bioaccumulation in goats was studied through repeated oral doses followed by serial slaughter of the animals. Twelve yearling local male goats were fed daily with 120 g commercial concentrate (17 percent CP), napier grass ad libitum, and were orally treated daily with 0.006 mg/kg body weight of 14 C monocrotophos. The animals were randomly selected for slaughter on days 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, and 36 of the dosing period. Urine and feces were collected separately for the measurement of monocrotophos elimination. The liver, biceps femoris, longissimus dorsi, and abdominal fat were also collected for monocrotophos residue analysis through radioactive measurement. The highest rate of accumulation of the pesticide was in the liver (0.063 ppm), followed by blood (0.049 microgram/ml), longissimus dorsi (0.047 ppm), biceps femoris (0.024 ppm), and abdominal fat (0.017 ppm). Based on the two-compartment model using non-linear regression analysis, the highest rate constant of monocrotophos uptake was found in the liver (0.02383 plus or minus 0.00485 microgram/g tissue/day), followed by longissimus dorsi (0.02356 plus or minus 0.00266 microgram/g tissue/day), biceps femoris (0.00784 plus or minus 0.00211 microgram/g tissue/day), and abdominal fat (0.00416 plus or minus 0.00074 microgram/g tissue/day). The trend of monocrotophos bioaccumulation in tissues followed non-linear regression: Q(t)=0.027 (e raised to 0.00025 t power-e raised to the negative 0.17474 t power), (R square=0.67); Q(t)=0.057 (e raised to the negative 0.0066 t power-e raised to the negative 0.25665 t power), (R square=0.86); Q(t)=0.017 (e raised to 0.0069 power-e raised to the negative 0.1358 t), (R square=0.93); and Q(t)=0.055 (e raised to 0.00995 t power-e raised to negative 2523 t power), (R square=0.88), for biceps femoris, longissimus dorsi, abdominal fat, and liver, respectively