This study describes the toxicity signs that developed when the diet of male broiler chickens was artificially contaminated with different levels of the mycotoxin ochratoxin A (OTA). Chicks were assigned randomly to three groups of 80 chicks that were fed a diet containing 0 parts per billion (ppb) (control, group 1), 400 ppb (group 2) or 800 ppb (group 3) OTA from day 1 to 5 weeks of age. Signs of ochratoxicosis were assessed on the basis of changes in the following criteria: body weight, relative weights of two representative internal organs (gizzard and thymus), feed consumption, feed conversion ratio, mortality, thyroid activity, blood profile, humoral and cell mediated immunity. Feeding OTA at levels of 400 and 800 ppb (groups 2 and 3) significantly decreased the body weight, thymus weight, feed consumption, feed conversion ratio and thyroxine concentration (P B/0.05). The OTA groups developed anaemia manifested by a significant decrease in the red blood cell count, packed cell volume percentage and haemoglobin concentration (P B/0.05). By the end of the experiment both groups that received OTA showed a 37% reduction in red blood cell count compared with the control group. Furthermore, a significant decrease in the white blood cell count, humoral immune response and cell-mediated immunity was found in both groups fed ochratoxin compared with the control group (P B/0.05). The reduction in the above parameters was more noticeable with time and was proportional to the level of OTA exposure. A significant increase in relative gizzard weight, cumulative mortality and triiodothyronine concentration was found in OTA-fed chicks (P B/0.05). These data provide a description of ochratoxicosis in broilers that should be useful in diagnosis and in improved understanding of the practical implications on broiler performance and health, a problem that can threaten the poultry industry.

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The present work was carried out to study the effect of inovo injection of ochratoxin A (OTA) as an oxidative stress and its consequences on hepatic and kidney functions, thyroid activity, and histological examination of brain and liver in chicken embryos and subsequently in the hatching chicks. On the 10 th day of incubation, one hundred and sixty-two fertile eggs were randomly divided into two equal treatments. Control treatment, (injected by 50 µl sodium carbonate) and OTA treatment (injected by 12.5 ng OTA dissolved in 50 µl sodium carbonate). OTA treatement group significantly reduced glutathione (GSH) and significantly increased thiobarbituric acid reactive substances production (TBARS) in embryonic and hatched chicks regarding livers, spleen, bursa of Fabricius, heart, and brain as an indicator of oxidative stress. OTA injection increased TBARS and decreased GSH levels in both allantoic and amniotic fluids. On the 14 th and 16 th days of incubation and at the hatch, a significant lower concentration in cholesterol and higher concentrations of alanine amino transferase, aspartate amino transferase, alkaline phosphatase, gamma glutamyl transferase, acid phosphatase enzymes activities and triglycerides in the hepatic tissues of the OTA group were observed. Histological examination of OTA group of brain and liver tissues showed some degenerative changes through the experimental period. In conclusion, in-ovo OTA treated had teratogenic and embryotoxic effects.

1. A trial was conducted to examine the effects of dietary vitamin E content, age and sex on haematological indices and liver enzymes of Japanese quails. A total of 800 1-d-old quail chicks were assigned at random into 4 equal groups and fed on starter and layer diets containing 0, 1, 5 or 10 times the NRC recommended supplements of vitamin E. No selenium was added to the basal deficient diets; the other diets were supplied with 0.2 mg selenium/kg diet. 2. The investigation covered the age span of 3 to 12 weeks in female and male birds. Blood samples were collected at 3-week intervals and tested for haematological indices (erythrocyte count; leucocyte count; susceptibility of erythrocytes to haemolysis; haemoglobin concentration (Hb); packed cell volume (PCV); and mean corpuscular volume (MCV)) and liver enzymes (aspartate transaminase, AST, and glutathione peroxidase, GSH-Px). 3. The significant differences between the 4 dietary treatments indicated that as the levels of selenium and/or vitamin E increased, the percentage of erythrocytes haemolysed and AST activity decreased, whereas Hb and GSH-Px concentrations increased. 4. Differences between age groups showed that older quails had higher erythrocyte susceptibility to haemolysis, higher AST levels and but lower erythrocyte count and PCV. 5. Females had lower erythrocyte haemolysis and higher Hb concentrations than males. 6. The interaction between dietary groups and age groups revealed that the differences between age groups were reduced as the level of selenium and/or vitamin E increased, leading to similar group means over the age period of study. 7. In conclusion, NRC recommended supplements of vitamin E (12 and 25 mg/kg diet) were not adequate. Doses equal to, at least, 5 times that recommended were advised to improve GSH-Px (index of antioxidant status) and Hb concentrations.

The present study was carried out to study the effect of inovo ochratoxin A (OTA) injection in Highline layer eggs on calcium metabolism and blood biochemical parameters of embryos and after the hatch. At day 10 of embryonic development, one hundred and sixty-two fertile eggs were individually weighed and divided into two equal treatments. The first treatment (control) consisted of the individual injection of fertile eggs with 50 µL sodium carbonate. In the second treatment (OTA), fertile eggs were individually injected with 12.5 ng OTA dissolved in 50 µL sodium carbonate. On days 12, 14, and 16 of incubation and at the hatch, serum calcium and inorganic phosphorus concentrations were lower (p<0.05), while sodium, alkaline phosphatase and triiodothyronine concentrations were higher (p<0.05) in the OTA-injected eggs compared with the controls. Serum potassium concentration was not affected (p<0.05) by OTA treatment. Lower calcium and phosphorus levels were determined (p<0.05) in the allantoic fluid of OTA-injected eggs compared with the controls. On days 12, 14, and 16 of incubation and at the hatch, lower whole body and yolk calcium and phosphorus, but not sodium levels, were measured (p<0.05) in the OTA treatment compared with the controls. In conclusion, the injection of eggs with OTA reduced blood calcium and phosphorus levels, which were associated with reduced whole body and yolk content from these electrolytes. Therefore, ochratoxin A had a negative effect on calcium metabolism.