The role of European starlings in the spread of coccidia within concentrated animal feeding operations.

To investigate the relationship between European starlings and bovine coccidiosis we collected samples from European starlings, cattle feed bunks, cattle water troughs, and cattle feces within concentrated animal feeding operations (CAFOs). These samples were screened for coccidia spp. to investigate (i) the prevalence of coccidia in starlings using CAFOs; (ii) if there is a relationship between bovine coccidiosis and starling numbers; (iii) if coccidia contamination of cattle feed and water is related to the number of starlings observed on CAFOs. Coccidia belonging to the genus Eimeria were detected in cattle feces and one water sample but no Eimeria spp. were detected in European starlings or cattle feed. However, many European starling samples were positive for Isospora. Starling use of CAFOs did not appear to be associated with coccidia spp. shedding by cattle and there was no correlation between starling numbers and contamination of cattle feed and water, suggesting that starling do not contribute to the amplification and spread of Eimeria in CAFOs.