Fish are one of the most extensively distributed organisms in the aquatic environment. A field study was conducted for 102 days at feeding period. A 100 fish/net-Hapa (Nile tilapia, silver carp, common carp and African catfish) were stocked at a rate of 1: 1: 1: 1 using a polyculture system. Two experimental net-Hapa/treatment were used, one treatment as a control fish fed a commercial diet and the second one fish were fed a Dried Sewage Sludge (DSS), product of treating sanitary and agricultural drainage of Al-Reiad city, Kafr El-Sheikh, Egypt). At the end of the experiment, blood samples were withdrawn for measuring the hematological and serum biochemical parameters, also liver samples were taken from each fish species for histopathological examinations. From the obtained results, it was clear that DSS feeding did not negatively affect the blood picture in general, although the significantly elevated values of transaminases activity and triglycerides concentration. The DSS feeding led to some drastic histological alterations in the liver structure. Conclusively, the presence of some pollutants from agricultural and urban drainages whether in the rearing water or in DSS that can negatively affect fish health, production and quality as well as could be inter the food chain and threat human health; so, it is recommended to give more concern on food and water quality (environmental friendly) used in aquaculture to offer more safe products for human consumption.

A b s t r a c t A r t i c l e I n f oA feeding trial for 60 days was carried out on rabbits to study the effects of 1,4-dioxane (3.2mg/Kg) including diets with or without vitamin C (1g/Kg diet, as antioxidant) on their blood profile and some internal organs' histology (kidney, liver and testis). From the obtained blood results and histological examination, it could be concluded that the dietary inclusion of 1,4-dioxane was responsible for occurring a case of multiple anemia [aplastic (toxic), leukemia toxicity, and malnutrition] besides toxic hepatic and biliary tract disease, dehydration, steatorrhea, edema, myocardial infarction and/or excessive protein catabolism.

In a field study conducted for 102 days at feeding period, using a polyculture system (Nile tilapia, silver carp, common carp, and African catfish at a rate 1: 1: 1: 1) in two Hapas, one for control fish fed a commercial diet and the second one fish were fed a dried sewage sludge (DSS, product of treating sanitary and agricultural drainage of Al-Reiad, Kafr El-Sheikh, Egypt). At the end of the experiment, blood samples were withdrawn and liver samples were taken from each fish species for hematological, biochemical and histological examinations. From the obtained results, it was clear that DSS feeding did not negatively affect the blood picture in general, although the significantly elevated values of transaminases activity and triglycerides concentration. DSS feeding led to some drastic histological alterations in the liver structure. Conclusively, and because of the presence of some pollutants from agricultural and urban drainages whether in the rearing water or in the sewage sludge that can negatively affect fish health, production, and quality as well as could be inter the food chain and threat human health; so, it is recommended to give more concern on food and water quality (environmental friendly) used in aquaculture to offer safe products for human consumption.

A feeding experiment was conducted with rats to reevaluate the possible toxic effects of very low level (tolerance limit) of ochratoxin A (OTA) and attempting to overcome this ochratoxicosis A via dietary supplementation of some essential oils. The obtained results revealed that the toxicated as well as garlic-oil groups of rats moisten their mats than the other groups' mats. Garlic-oil group also excreted more wet feces and had the lowest daily bodyweight gain as well as the worst feed conversion ratio comparing with the other groups. Garlic oil containing diets (whether with or without the toxin) reflected very low bone mineral density, whereas all toxic diets (with or without garlic or marjoram oils) and marjoram oil alone reflected high bone mineral concentration but the lowest value was obtained with garlic oil alone. Bone area was increased in all treatments, except garlic oil group. However, the highest area was in marjoram group. Lean mass was the lowest in the toxic diets with or without garlic oil. Fat mass was at lowest value in the toxic diet plus marjoram and the highest in the toxic diet plus garlic oil. OTA and/or the tested essential oils affected also the post-mortem, relative weights (particularly spleen), the blood profile (particularly Glob, Glu, AST, Cre, alkaline phosphatase, LDH, testosterone, lymphocytes, monocytes, and granulocytes), proximate analysis of the biological tissues, and the histological structure of the internal organs. So, even the very low concentration of OTA (25 ppb, as a dietary tolerance level in some countries) used in this study, it may be harmful and dietary essential oils inclusion could not completely overcome its toxic effects. So, it is still a fact that prevention (of mold growth) is easier, cheaper and more effective and better than curing of mycotoxicosis.

A feeding experiment was conducted with rabbits as experimental animals for 2 months at 4 treatment groups under the same environmental conditions. The aim was to study the toxic effects of dietary graded levels of polyethylene (PE, 0, 1, 2, and 4 g/ton diet). The main effects were that some animals fed the PE-contaminated diets suffered from mange, diarrhea, weakness, and/or loss of weight. Post-mortem examination of the contaminated-diets fed rabbit revealed presence of bad smell liquids in its abdomen, residues of collective PE in the small intestine, collective feces in one part of the intestine and the parts were filled with aqueous accumulation, the color of one hepatic lobule was pale, and the lungs' color was bloody red. Yet, feed intake and water consumption increased by feeding the contaminated diets. Moreover, animals offered the contaminated diets reflected heavier body weight. However, the feed conversion (utilization) was negatively affected by the PE- contaminated diet; since, dietary PE-inclusion increased apparently feed consumption than the real body weight gain. Slaughter test of the PE-treated animals reflected many remarks including loss of rabbit's weight; increased skin weight, skin was thick and dough, changes in the color and quality of the carcass flesh, easy broken bone. When these animals were eviscerated, it were observed white-colored lungs, with necrosis and bloody infiltration, small-sized liver, with blackly-red color, enlarged gall bladder, narrow diameter of the small intestine, presence of collective mass of PE on the internal wall of the small intestine. The presence of PE in the experimental diets was responsible for significant lowering the specific gravity of the treated animals' bone, as well as their flesh moisture and fat; yet, their crude protein increased besides their edible parts and boneless meat percentages increased too, but not significantly. Dietary contamination with PE reflected its residues in the rabbits' flesh and increased the flesh content of ash (P>0.05). The contaminated diets were responsible for significantly (P≤0.05) evaluating lymphocytes %, MCV, MCH, and PLT and lowering both monocytes and granulocytes % as well as RBCs count. Significant (P≤0.05) increases in albumin, creatinine and uric acid concentrations and decreases of ALT activity were recorded with feeding rabbits the PE-contaminated diets; but, Cho. and Trig. concentrations were decreased (P≤0.05). There was a significant increase of scores of hepatic congestion and necrosis in liver from rabbits group received 0.4 PE when compared with control group. Statistical analysis shows significant increase of scores of renal congestion, fibrosis and acute tubular necrosis in group received 0.4 PE when compared with control group. Hence PE negatively affected rabbits' performance, health and quality, and may affect the consumers' health too.