Honors Theses

Date of Award


Document Type

Undergraduate Thesis



First Advisor

Richard Buchholz

Relational Format



Coccidiosis is a disease of the gastrointestinal system of commercially raised chickens (Gallus gallus). The infection is caused by multiple parasitic species of the coccidian genus Eimeria. Eimeria proliferate within large poultry houses leading to decreased nutrient absorption, anorexia, and death of the host. Scheduled vaccination with live coccidian oocysts should minimize production losses, but various management factors may contribute to variation in the outcome. I investigated whether by tracking infection cycles in detail it might be possible to improve poultry production. Feces were collected daily from four farms across a two-month period to understand how peaks in oocyst shedding by the hosts affected mortality and bird weight. 2nd peak shed values (maximum OPG counts following secondary infection) showed significant correlation to early weight loss but not mortality. Additionally, I found no difference in 2nd peak values between males and females; however, differences in density may have caused the effect. Because oocysts per gram (OPG) numbers were homogenous across the house by day 21, turn out of birds from brood end to off end did not significantly affect spatial distribution of oocysts. I conclude by describing how coccidian burden varies among chicken producers nationally and internationally and proposing improved methods for oocyst monitoring.

Included in

Biology Commons



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