Validation of a new proposal of quantitative sperm culture for industrialized bull semen

The Brazilian Ministry of Agriculture (MAPA) has discussed the mandatory culture of industrialized semen, both to ensure biosefety, and to prevent in vitro fertilization problems caused by oocyte contamination with ubiquitous and opportunistic bacteria from preputial microbiota. Pour plate, a quantitative technique recommended by the World Organization for Animal Health (OIE), is operationally difficult and costly for routine analysis in Artificial Insemination Centers (AICs). The objectives of this study were to evaluate and validate viable superficial bacteria counts (VSBC), in CFU/mL, compared with pour plate counts, in industrialized bull semen samples from AICs. Semen straws from Projeto Hungria - MAPA bulls were used. VSBC and pour plate were carried out in parallel in serial dilutions of the samples, from 10(-1) to 10(-5). CFU/mL means or medians recorded in each dilution and technique were compared, and no statistical differences were observed between the two techniques regarding the quantification of bacteria in CFU/mL, suggesting that it may be possible to replace pour plate for CBSV, a cheaper and more practical technique.