An Evaluation of the Plasma Levels of Frequently Used Pesticides in Dairy Cattle and Its Possible Correlation with the Occurrence of Follicular Cystic Ovarian Disease: A Case-Control Study

Background: Cystic ovarian disease (COD) is one of the common reproductive disorders which affecting the fertility of dairy cattle induces heavy financial burdens on herds owners. Various insecticides, fungicides and herbicides, collectively known as pesticides are frequently used in the agricultural systems of different countries. Given the fact that pesticides are known to have endocrine disrupting properties, exposure to these compounds may play a role in the development of COD. Materials and Methods: The plasma concentrations of a complete profile of common pesticides including organophosphorus, organochlorine, and carbamate and pyrethroid compounds in the plasma of cattle with COD compared to healthy controls was examined. Moreover, plasma concentrations of inflammatory cytokines as well as oxidative stress parameters were investigated. Results: No significant amounts of any of the pesticides investigated were detectable in the plasma of neither the healthy nor cystic cows. The plasma indices of total antioxidant capacity (TAC), thiol, lipid peroxidation (LPO), and reactive oxygen species (ROS) did not show any significant differences between the affected and the control groups. Tumor necrosis factors alpha (TNF-α), progesterone, lymphocyte, neutrophil, fibrinogen and MCHC had significantly higher amounts in the plasma of COD cows. Conclusion: Findings of the present study do not support the notion that exposure to the studied pesticides is a contributing factor in the development of follicular cysts in dairy cattle. In addition, TNF-α might be affected as a factor in the pathogenesis of COD by an independent pathway of pesticides effect.