Presence of paratuberculosis in dairy cows culled in Tizayuca (Hidalgo, Mexico) ¤/Presencia de paratuberculosis en vacas lecheras de desecho en Tizayuca (Hidalgo, México)/Presença de paratuberculose em vacas leiteiras de descarte no Tizayuca (Hidalgo, México)

This paper aims to determine the proportion of cows positive for Mycobacterium avium subsp. paratuberculosis (Map) among culled cows. In the present study, 40 culled cows from 25 farms located at the complejo agropecuario industrial de Tizayuca (CAITSA) in Hidalgo (Mexico) were evaluated for PTB presence by histopathological and microbiological studies. Tissue and rectal scraping samples were taken from all cows, and studied for presence of histopathology PTB-compatible lesions. Samples were processed for Map isolation on selective agar culture media; typical Map colonies were confirmed by polymerase chain reaction (PCR). Potential PTB infection was found in 25% (10/40) of the animals evaluated by histopathology and acid-fast bacilli (AFB) staining, but only 7.5% (3/40) were positive for type 2 Map (C cattle strain) by PCR. The prevalence of PTB in cattle farms at CAITSA was confirmed, which may be valuable epidemiological information in Mexico.