The study was designed to identify different species of the genus Eimeria in broiler chicks occuring in poultry farms situated in and around Lahore.

For this purpose one thousand faecal samples were collected from different broiler farms out of which 145 (14.5%) were positive for coccidiosis. Two hundred broiler carcases, suspected to he suffering from coccidiosis were obtained from different diagnostic Laboratories at Lahore. One hundred and ninety out of 200, (95%) were found positive for coccidiosis.

Identification of the species of the genus Eimeria was done and seven species were identified i.e, E tenella 119 out of 190 (62.63%), J. brunetti 27 (14.21%), E. necatrix 13 (6.84%), . acervulina 19 (10%), . maxima 4 (2.10%), . mitis 3 (1.58%) and . praecpx 5 (2.63%).

The second aim of the present study was to compare the immunogenic properties of locally prepared (atlenuated) and imported (live) vaccine (Immucox). For this purpose one hundred and fifty five day old broiler chicks were reared under controlled conditions. They were equally divided into five groups i.e. A, B, C, D and E. Group A was kept as uninfected control. Group B acted as infected control. Group B, C, D and E were infected with 50,000 sporulated Oocysts at day 15, 25, 35 and 45 of age. Group C acted as infected and treated control alongwith 5 days treatment with amprolium, after three days of each primary and challenge doses. Group D received 1000 sporulated formalin treated oocysts orally, at the age of day 3 and day 10. The members of group E received orally imported vaccine (Immucox) at the age of day 5.

Immunogenicity was measured by the passage of oocysts per gram of faeces (OPG) and by comparative weight gains amongst different groups. It was noticed that no coccidiosis could be established in groups A, C, D and E. The OPG counts remained nil in groups A and C throughout the experimental period. Groups D and E showed moderate counts and Group B showed high counts of OPG. The OPG counts gradually decreased to 35,000, 1200 and 1150 in groups B, D and E, respectively at the end of the experiment.

Average weight gain records showed 430, 150, 332 and 270 gms greater in A, C, D and E groups, respectively at the end of the experiment, as compared to group B.

FCR of group A, B, C, D and E was 2.82, 3.48, 3.11, 2.76 and 2.93, respectively at the end of the experiment. Group D was the best and group B was the worst. Group D depicted full protection and remained second to the uninfected control group (A) in respect of weight gains. Group E also showed complete protection and remained third to the uninfected control group A in respect of weight gains. Inspite of complete protection in group C due to amprolium treatment, the weight gains remained lower than groups D and E. There was no development of exogenous species of Elmeria due to immunization with immucox.