Summary The purpose of the present study was to determine if there was a correlation between chick mortality and the presence of Clostridium perfringens alpha- and netB-toxins in C. perfringens recovered from litter in commercial broiler houses. Because coccidiosis predisposes chickens to necrotic enteritis, the concentration of Eimeria oocysts in these samples was measured and the numbers used in similar correlation analyses. Litter samples were collected at 0, 2, and 4 weeks growout from 6 broiler farms (18 houses total) during an anticoccidial drug (ACD) control program and from 9 broiler farms (23 houses total) during an Eimeria vaccine (VAC) control program. Of these, litter samples were collected from 5 farms during both ACD and VAC programs. The litter samples were processed for Eimeria oocyst and C. perfringens spore enumerations using standard parasitological and microbiological techniques. DNA was also extracted for C. perfringens DNA for PCR detection of genes coding for alpha- and netB-toxins. A general trend during the ACD programs was a transient decrease in both E. maxima and non-E. maxima (Eamipt) numbers at 2 wks growout. The pattern was slightly different during VAC with E. maxima and Eamipt levels increasing over time. Average concentrations of C. perfringens in litter were highest at 2 weeks (~ 105-6 spores/g) during ACD and at placement during VAC (~ 105-6 spores/g). During the ACD program a strong correlation was observed between 0-3 wk chick mortality and the presence at placement (0 wk) of netB-toxin (r = 0.42-0.48) or alpha-toxin (r = 0.55 – 0.67). A very strong correlation was observed between 0-5 wk chick mortality and the presence of netB-toxin at 4 wk growout (0.73 – 0.95). During a VAC program, a strong correlation was only observed between the presence of netB-toxin at placement and 0-1 wk chick mortality (r = 0.67).

This content is only available as a PDF.
You do not currently have access to this content.