The investigation was conducted to study the effects of organophosphate insecticide Trich- lorf on (Ditrifon) on the hematology and liver, kidneys, heart and spleen of the broiler chicken. One hundred and twenty day old broiler chicks were reared upto 3 weeks of age, then they were randomly divided into four groups i.e. A, 8, C and D containing 30 chicks in each group. Group A was maintained on afeed containing Ditrifon at dose rate of 400 mg/kg in feed. Group, B was maintained on a feed containing Ditrifon at dose rate of 200 mg/kg in feed. Group C was maintained on a feed containing Ditrifon at dose rate of 100 mg/kg in feed. Group D was kept as control. All the said groups were maintained on said feed for 7 days. The weights of the birds from each group were taken before treatment with Ditrifcon. All the groups were kept under close observation to record signs and symptoms of Ditrifon toxicity upto the end of 4 weeks and 5 weeks of age 15 chicks from each group were slaughtered for the hasmatology (PCV, Hb concen- tration, TEC and TLC) and histopathological studies (liver, kidneys, heart and spleen). The weight of the chicks from each group were taken and recorded before slaughtering.

There was a significant decrease in weight in groups A,E4 and C as compared to control group D.

Antemortem symptoms were recorded throughout the experiment and observed that feed intake of the treated groups was decreased, growth was retarded significantly. The treated birds of Group A and Group B showed dyspnoea, tremors, exhaustion, incoordination, ataxia and paralysis. The treated birds of group C showed no antemortem symptoms.

The main necropsy findings were small hemorrhages through out the body muscles, hepatomegaly, spleenomegaly, enlarged heart, swollen kidneys and gastroenteritis in group A and B, hepatomegaly and gastro enteritis in group C. Haematological alterations were studied in all the groups i.e. A, B, C and D. There was no significant difference found in packed cell volume, hemoglobin concentration, total erythrocytic count amongst all the groups, at both the ages. The total leukocytic count showed a significant increase in group A and B as compared to control group D. No significant increase was noted in group C as compared to group B and no significant increase between 28 and 35 days of age in groups A, B and C was noted.

The main histopathological lesions of liver and kidney included cloudy swelling, necrosis, and leukocytic infiltration in all treated groups i.e. A,B and C. Histopathological lesions o-f spleen included presence of focal areas of necrosis in group A and group B after 28 and 35 days of age. In group C after 28 and 35 days of age the spleens were normal. Histopathological lesions of heart were haemorrhage and cloudy swelling in the myocardium in group A and B after 35 days of age. No lesions were observed in all the treated groups after 28 days of age and in group C after 35 days of age. No changes were observed in liver, heart, spleen and kidneys of group .D (control).