A survey on the incidence and magnitude of intestinal helminthiasis in broiler breeders originating from the southeastern United States1

SUMMARY A survey was conducted to determine the incidence and magnitudes of parasitic helminth populations in broiler breeders. To that end, intact intestinal tracts were submitted by personnel from 10 poultry companies located in the southeastern United States. A total of 281 intestines were submitted, with 5 to 6 intestines being submitted from each of 47 breeder barns representing the 10 poultry companies. The birds selected for sacrifice were obtained at random from each barn, and ranged in age from approximately 30 to 49 wk at posting. Intestines were extracted on site, placed individually in plastic bags, chilled, and mailed overnight to the University of Arkansas for parasite collection, identification, and quantification. All intestines were identified with company, farm, bird age, and grower ranking. The majority of intestines were submitted with information relative to anthelmintic treatments given previously to the birds in the pullet house as well as specifics concerning bedding (number of flocks on current bedding). Of the 281 intestines submitted in the survey, only 3 were found to be void of helminth parasites, resulting in an overall infection incidence of 98.9%. Helminths isolated and identified from the intestinal tracts (and overall incidences) were Heterakis gallinarum (96%), Capillaria obsignata (75%), Ascaridia galli (63%), and Raillietina cesticillus (14%). Helminth counts for individual birds ranged from zero to a maximum of 3,240, 1,280, 940, and 445 for H. gallinarum, C. obsignata, A. galli, and R. cesticillus, respectively. Helminth levels varied significantly by company, but not significantly by grower ranking, although a direct correlation was evident between each parasite population and grower ranking (lower producer rankings were associated with higher helminth burdens). No correlation was detected between the helminth levels as seen in the surveyed birds and prior anthelmintic usage when the birds were in pullet production—an illustration of the refractory or compensatory nature of helminths and the inability of current treatments to control helminthiasis in breeders.