A total of two hundreds of slaughtered animals; 50 each of cattle buffaloes, sheep and buffalo calves were collected from slaughterhouse Giza. Each animal was represented by muscular part, prenephric fat, liver, and kidneys. The Four Plate Technique (FPT) is intended to detect antimicrobial residues in collected samples. The liver samples showed high detection incidences (30, 16, 16 and 8%) in cattle, buffaloe, sheep and buffaloe calves respectively as compared to kidney samples (16, 12, 10 and 6% respectively). The lowest incidence was detected in fat samples (0%) followed by muscle samples (4%). High incidence was detected in medium I followed by medium II and III, finally medium IV as well as medium V which failed to be showed any incidence of detection. The tetracycline residues in tissues of slaughtered animals depend on husbandry as well as on withdrawal time after use. The liver (67 + 15, 50 + 14, 54 + 10 and 3 +0.8) and kidney (63 + 16, 46 + 12, 56 + 12 and 8 + 2) samples in cattle, buffaloe, sheep and buffaloe calves respectively showed high residual levels as compared with muscles and fat. The detection of sulfonamide residues in tissues of slaughtered animals may be attributed to misuse of these compounds for long term in animal feed as well as result in accumulation in animal tissues.

Ninety chicks were experimentally, orally received different doses of estradiol-17β and diethylstilbestrol with ration. Samples were collected from tissues (wings, breast muscles, thigh muscles, skin and fat) and giblets (liver and gizzard) for detection of hormonal residues after 4 and 21 days from the last dose, which proved the presence of such residues in all samples. Effect of temperatures (boiling, roasting and freezing) on hormonal residues of positive samples was evaluated. It was proved that There is no significant variations in reduction of hormonal residues in each of breast and thigh muscles of chickens at (p < 0.05) after boiling, roasting and freezing at - 20˚ C as well as a significant differences was detected in skin and fat samples at (p < 0.05) after boiling and roasting. Public health importance of hormonal residues was discussed.

Fifteen samples of fish fillets were collected from different Egyptian markets to detect the residues of some heavy metals in them. The average weights of fish fillets samples were 250g. The samples were separately packed in polyethylene bag and sent to the laboratory for preparation and analysis. All equipment surfaces and utensils which used in this study were thoroughly cleaned with detergent, rinsed with water, dried and then rinsed with 2-propanol solution. The samples were stored at –2C prior to analysis. The mean levels of lead and cadmium in fish fillets collected from the Egyptian markets were 1.51  0.34 and 0.60 0.0.25 mg/kg; respectively. The concentration of lead in fish muscle were less than the permissible heavy metal limit in fish meat (2.0 mg kg) as stated by the World Health Organization, also these results were in line with the corresponding EU regulations. However the level of cadmium concentration was over than the heavy metal limits in fish meat (0.5 mg/kg) for the World Health Organization.