Clostridium tyrobutyricum occurrence in silages and cattle feed: use of molecular and simulation data to optimize predictive models

Introduction: Poor quality silage can derive from the presence of deleterious\r\nmicroorganisms such as clostridia. Their dissemination along the food chain, especially\r\nin milk, causes issues such as the cheese late-blowing defect, particularly triggered\r\nby Clostridium tyrobutyricum. The scope of our study was to determine the C.\r\ntyrobutyricum occurrence in three different farms across four time periods in relation\r\nto the animal diets, specifically the Total Mixed Ration (TMR), by using real-time PCR.\r\nMethods: For this purpose, molecular-derived data were exploited to optimize\r\na predictive model that simulated the farm conditions favoring the growth of\r\nbutyric acid bacteria such as C. tyrobutyricum.\r\nResults: Our results showed that the originally utilized predictive model strongly\r\nunderestimated the growth of C. tyrobutyricum in comparison to the molecular data.\r\nAt the same time, our findings uncovered an additional source of contamination in\r\nthe TMR related to silage and dietary residues that represent a reservoir of microbial\r\ncontamination during successive TMR preparation. Based on these findings, the\r\noptimization of the model parameters such as growth rate range and the inclusion of\r\nthe residues in the model, allowed a more accurate prediction of the contamination\r\nlevels. Therefore, this study revealed that proper hygiene practices such as the removal\r\nof silage and TMR residues within the farm environment is essential to control the\r\ncontamination by C. tyrobutyricum and avoid food waste and economic losses.