Investigation were carried out to devlop a new techi~ques using High Performance Liquid chromatography (HPLC)with ultraviolet detectors for detection of DDT and dield-rin as representative for organochlorine Pesticides as wellas Rabon as the representative for organophosphorus insec-ticide, second to discuss the effect of low concentrationsof insecticide DDT and dieldrin on some production charac-teristics, third to discuss the DDT and dieldrin residuesin natural water surfaces, and fourth to discuss under thefield condition the effect of Rabon spraying inside thepoultry houses cin some production characteristics. 1. The experiment 1 showed that two organochlorine insec-ticides, dieldrin and DDT are present in the recycled cattle manure used to formulate the ration of poultry,the actual concentration of DDT is calculated to be 0.34 ppm, and that for diedrin 0.0002 ppm.from experiments 2. and 3 the accumulation of dield-rin and DDT in eggs of hens fed dieldrin and DDT atthree dietary levels over 42 weeks period showed arelation with the amount in the diet, Wnenever thereLiterature on pharmacodynamics of flumequine is relat- ively sparse. Hence, the present work was conductedto gain more explicit information on the possible, if any, side effects of the drug, through studying itspharmacodynamics in chickens, antibacterial and histo-pathological effects. Effects On Isolated Preparations:- In the present investigation, flumequine insmall doses st~mulated the motility of isolated smooth muscles of both the intestine and oviduct of chickens.~anwhile, the drug in large doses, exerted an inhib-nor y effect on the motility of these muscles. Thestimulatory effect of the drug, in small doses, might ~ attributed to a central cholinergic agonist activ-ity. However, the inhibitory effect of the drug, in large doses, appeared to be due to a central choline-rgic antagonist acti vi ty .