Abstract   

The effects of the organophosphorus Supracide and the pyrethrois Sharkesuper on the serum concentration of thyrotrophic (TSH), triiodothyronine (T3), thyroxine (T4), estradiol, progesterone, follicle stimulating (FSH) and luteinizing (LH) hormones in mature female rabbits were investigated. The results indicated that the short (9 days) and long (45 days) treatments of rabbits with both Supracide and Sharkesuper through drinking water at a rate of 1/10 LD5O exhibited varying degrees of reduction in all hormones studied. The degree of reduction in the concentrations of progesterone produced by long-term administration of Supracide was more pronounced than that produced by Sharkesuper. On the other hand, Sharkesuper treatment had more capacity to reduce the levels of other hormones nearly to half their control levels than that evoked by supracide. This reveals that the impairment in each of thyroid function, reproductive performance and fertility rate was more evident by exposure to Sharkesuper rather than Supracide. Therefore, it becomes of utmost significance to limit or prohibit utilization of such pesticides to avoid the economic losses that can be caused among rabbit breeds.