Prevalence and Predisposing Factors in Spontaneous Cases of Necrotic Enteritis in Cage Reared Commercial Layer Chicken

Necrotic enteritis (NE) caused by C. perfringens is one of the economically important disease in broiler chicken. Nowadays frequent outbreak were noticed in commercial layer flocks maintained in raised cage system and causing mortality and decreased egg production. Hence the present study was undertaken to assess the prevalence and predisposing factors associated with spontaneous cases of necrotic enteritis in cage reared commercial layer chicken. A total of 1000 white leghorn carcasses, above 20 weeks (wk) age from 100 flocks with gastrointestinal tract disorders were screened for the presence of necrotic enteritis lesions and C. perfringens out of which 28 flocks (28%) showed lesions and organism. All the 28 isolates were identified as alpha toxin producing strains by PCR technique. Affected flocks showed depression, soiling of vent with brownish fecal materials and sudden death. Necropsy revealed dilated intestine and Turkish towel appearance of mucosa due to necrosis caused by alpha toxin of C. perfringens. Necrotic enteritis was recorded as single (13 %) and combined (15%) infection with coccidiosis (11%), worm infestation (2%) and Newcastle disease (2%). Highest prevalence was noticed in the age group of 21-30 wk (42.86%) and Northeast monsoon season (60.71%). dro‎p in egg production and mortality in the affected flocks was 3.0 to 10 and 2. 72 to 3.15 % respectively. Incidence of disease was more in flocks which used animal protein as a source of feed ingredient.