PREY ALENCE OF COCCIDIOSIS IN BROILERS ON TWO FARMS IN BANGLADESH

Abstract

Litter oocyst counts and lesion scoring of naturally infected chicken were carried out to study the prevalence of coccidiosis
in broilers on two farms in Bangladesh. Except in one crop, the pattern of weekly litter oocyst counts and the
rate of infection were very similar on both the farms. Oocysts were normally detectable in litter early at two weeks with
gradual increase to reach a peak at five weeks (9-22 x 1()3 per gramme of litter) and then declined. Although the rate of
infection was higher at six weeks, in most cases the severity o fles ions was almost equal both at4 and 6 weeks, and mostly
E. acervulina and E. tenella were responsible for these lesions. Five pathogenic species of Eimeria were detected in this
study. Eimeria acervulina was the commonest and found in upto 80% birds examined at 6 weeks. With E. tenella, E.
maxima, E. brunetti and E. necatrix, these rates were 70, 40, 30 and 20% respectively. E. tenella, E. maxima and E.
brunetti occurs on and from 2 weeks whereas E. acervulina and E. necatrixnever before 4 weeks. Coccidiosis was more
prevalent during cold months of the year.