Evaluation of level of pesticide residue in blood and its effects on hormonal levels of crossbred bulls

The pesticides are potentially toxic compounds that have become omnipresent in the environment. These toxicants modulate and/or disrupt the reproductive and hormonal environment by acting on hypothalamus, pituitary and reproductive organs. Fewer studies have been carried out on pesticide residues in body fluids especially blood and semen in breeding bulls.

Study was done to assess the pesticide residues in blood in relation to the endocrine profile in crossbred breeding bulls. Nineteen blood samples were collected and were allowed to clot overnight; serum was separated and stored at −20°C until analysis. The samples were analyzed for the pesticide residues using gas chromatography (GC) for seven organochlorine pesticides (OCPs) namely Heptachlor epoxide, Chlordane, Fipronil, Lindane, Methoxychlor, op-DDT and Endrin and eleven organophosphorus pesticides (OPPs) namely Chorpyrifos, Dichlorovos, Ethion, Monocrotophos, Malathion, Parathion-methyl, Profenphos, Phorate, Triazophos, Quinalphos and Phosalone and four synthetic pyrethroids (SPs) namely Cypermethrin, Permethrin, Deltamethrin, Cyhalothrin.

The blood samples of these bulls were found positive for organophosphate-phosalone and around 73.68% of the bulls were positive for phosalone at a retention time of 13.837 min. The concentration of phosalone in the blood of crossbred breeding bulls was found to be 1.89±0.98 ng/ml. In the present study, the blood hormonal profile of pesticide residues was analyzed and it showed a significant increase in the level of Estrogen there by decreasing the testosterone: estrogen ratio. The decreased testosterone: estrogen ratio may be attributed to the detection of phosalone in blood.