Prevalence of sp. in Broiler Poultry Houses with Positive and Negative Pressure Ventilation Systems in Southern Brazil.

Coccidiosis is an enteric disease caused by protozoa of the genus and is of great economic relevance in industrial aviculture. The objective of this work was to determine the prevalence of sp. in broiler poultry houses with positive (System 1) and negative (System 2) pressure ventilation and assess the associated factors. A transversal study was conducted using 8 random broiler chickens from 64 houses ( = 512) and macroscopic and histologic evaluation of the intestines, as well as PCR for sp. The prevalence of sp. was 90.6% (95% confidence interval [CI]: 97.8-83.5), with 93.8% (95% CI: 100-85.4) in System 1 and 87.5% (95% CI: 99.0-76.0) in System 2. The most prevalent species was , and the most common combination was , , and . System 2 and the negative subgroup showed the best results for feed conversion and daily weight gain. By evaluating litter treatment, we found that quicklime reduced the risk of presence of and . In conclusion, sp. had a high prevalence in both systems, with a predominance of mixed infections. System 2 and negative flocks showed the best zootechnical results.