The aim of the study was to determine whether the alternative yeast species Yarrowia lipolytica in turkey feed would have a more beneficial effect on growth performance and intestinal histology than the commonly used species Saccharomyces cerevisiae. An additional objective of the study was to test whether the addition of a probiotic to feed containing Yarrowia lipolytica or Saccharomyces cerevisiae yeast would enhance its effect on growth performance and intestinal histology in turkeys. The experiment was carried out on 480 turkey hens randomly divided into six groups. Birds from the control group (C) and group P were fed standard feeds but group P additionally received a probiotic (0.05%). Groups Y and YP received feed containing Yarrowia lipolytica fodder yeast (3%), and the YP group received also the probiotic (0.05%). Similarly, in groups S and SP, the turkeys received feed with Saccharomyces cerevisiae fodder yeast (3%), and for the SP group the probiotic was added to the feed (0.05%). Yarrowia lipolytica yeast added in the amount of 3% to the turkey feed may be an alternative to the commonly used Saccharomyces cerevisiae yeast, because it improved growth performance, and above all, had a more beneficial effect on intestinal histology. The use of Yarrowia lipolytica alone can be beneficial for growth performance, while the combined use of 3% Yarrowia lipolytica in the feed and a 0.05% addition of a probiotic containing Bacillus licheniformis and Bacillus subtilis has a more beneficial effect on gastrointestinal histology.
