This study was conducted as a field study to select the most effective disinfectants for control of the microbial contamination in poultry farms through evaluation of some commercial disinfectants. All tested commercial disinfectants were diluted with sterile tap water and applied at different concentrations (0.5 and 1.0 %) on contaminated surfaces (concrete) by spraying at a rate of 0.5 liter/m 2. The Aerobic Plate Count (APC) on naturally contaminated floor of broiler farm was determined before the application of commercial disinfectants at different concentrations with contact times of 15, 30, 60, and 120 minutes. The results revealed that disinfectants at concentration of 0.5% had little action on the tested pathogens as S. Typhimurium, E. coli and S. aureus after 30 and 60, 90 and 120 minutes contact time. While, application of Virudox-G, Glutarol and Alkadox at concentration of 1% for 120 minutes contact time was efficient and proved 100% reduction either for of the pathogens count. While, Phenodex showed the lowest inhibitory effect on these pathogens.

The present study was carried out to investigate the persistence of some pesticides (diazinon and deltamethrin) in water, feeds and milk. The obtained results illustrated that diazinonwas persisted for longer time in water, feed and milk samples than deltamethrin, it disappears within 21 st and14 th day after application in water and feed, respectively, while it disappears within 30 th day after application in milk. Moreover, deltamethrin disappear within 7 th day after application in feed and water, while in milk it disappears within 21 st day after application. We concluded that diazinon and deltamethrin were persisted in milk for longer time than both feed and water. Pesticides contamination of milk and milk products may lead to acute or chronic toxicity for human being representing public health hazards through their cumulative effects.

The present work was carried out to study the effect of seasonal variations on the levels of pesticide residues in water, feeds and milk. Our results illustrated that the significantly highest concentrations of OCs in water and feed were detected during summer [(1.05±0.35, 0.72±0.24, 0.77±0.25, 2.5±0.70 and 0.81±0.27 µg/L, for p.p.DDT, aldrin, β-BHC, lindane and γ.chlordane respectively in water samples) and (30.0±10.20, 45.00±13.02, 65.33±21.90, 35.33±13.20, 43.67±13.30, 22.00±7.33 and 19.13±8.6 µg /kg, for p.p.DDD, p.p.DDE, p.p.DDT, aldrin, lindane, γ.chlordane and methoxychlor, respectively in feed samples) ], while the lowest were detected during spring, on the other hand, none of pesticides detected in winter which may be attributed to environmental factors. The significantly highest concentration of diazinon in water and feed was recorded during autumn (78.75±26.30 µg/L and 140.00±64.60 µg/kg, respectively), while the lowest levels were detected during spring. Also, the highest concentrations of deltamethrin was detected during spring in water (55.30±18.50 µg/L) and during summer in feed samples (78.40±26.70 µg/kg), while the lowest levels were detected during autumn in water and during spring in feed samples. The significantly highest concentrations of residues in milk were detected during summer (p.p.