Mattia Fustini, Marina Losio, Frederique Chaucheyr Durand, Chloe Deneufbour, Andrea Formigoni, Helene Tormo, Henri Durand, Ester Grilli, Grilli, Ester, Tormo, Helene, Fustini, Mattia, Deneufbourg, Chloé, Losio, Marina, Formigoni, Andrea, Chaucheyras-Durand, Frederique, Durand, Henri, DIMEVET, University of Bologna, Ecole d'Ingénieurs de Purpan (INPT - EI Purpan), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna 'Bruno Ubertini' (IZSLER), Unité de Microbiologie (MIC), Institut National de la Recherche Agronomique (INRA), Lallemand Animal Nutrition, Istituto Zooprofilattico Sperimentale della Lombardia e dell' Emilia Romagna Bruno Ubertini, Microbiologie Environnement Digestif Santé (MEDIS), and INRA Clermont-Ferrand-Theix-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])
Live Saccharomyces cerevisiae yeast strains are widely used as feed additives for dairy cow s. Although, perfectly safe and applied in several food processes, the potential contamination of milk by the strain and more generally its possible influence on the microbial profile of milk could be questioned, this concerns particularly traditi onal cheeses made with raw milk. In an attempt to address these questions, two experiments were performed: A trial in an experimental farm , where two groups of cows, one receiving yeast supplementation and the other one being an unsupplemented control, were compared and a field trial where herds received alternatively yeast-supplemented and control diets. In both cases, viable counts of different microbial groups, including yeasts and molds in general and S. cerevisiae in particular were analysed in tank milk and results from suppleme nted groups or periods were compared with control ones. No v iable S. cerevisiae were detected in any of the samples analysed. Moreover, no n oticeable differences in the microbial profiles were observed. This applies also to the evolution of the microbial composition during an experimental cheese processing trial. These data sug gest that live yeast additive distributed to dairy cows does not influence milk microbial composition and cheese-making abilities.