Effect of the use of Yarrowia lipolytica and Saccharomyces cerevisiae yeast with a probiotic in the diet of turkeys on their gut microbiota and immunity

An experiment was carried out to determine whether the yeast species Yarrowia lipolytica added to compound feeds for turkeys would have a more beneficial effect on their immunity and gut microflora composition than the commonly used species Saccharomyces cerevisiae. An additional aim of the study was to test whether the addition of a probiotic (Bacillus licheniformis and Bacillus subtilis) to the feed containing Yarrowia lipolytica or Saccharomyces cerevisiae yeast would enhance their effect. The experiment was carried out on growing turkey hens aged 7 to 112 days and randomly divided into six groups (each n = 80). The birds in the control group (C) and group P were fed standard feeds, but group P additionally received a probiotic. Groups Y and YP received the feed containing the Yarrowia lipolytica fodder yeast, and the probiotic for the YP group. Similarly, in groups S and SP, the turkeys received the feed with the Saccharomyces cerevisiae fodder yeast, and the probiotic was additionally added to the feed for the SP group. Yarrowia lipolytica yeast can be an alternative to the commonly used yeast Saccharomyces cerevisiae in turkey feeds. Yarrowia lipolytica favourably influenced the intestinal microbiota (reduced the number of microorganisms - P < 0.001, fungi - P < 0.001, and coliforms - P < 0.001, including E. coli), and stimulated erythropoiesis (increased Hb content - P = 0.049 and RBC count - P = 0.027; increased Ht - P < 0.001) and immune mechanisms (increased the %pc - P = 0.021, NBT value - P = 0.013 and lysozyme content - P = 0.013; decreased IgM concentration - P = 0.049). The combined use of a probiotic with yeast, particularly Yarrowia lipolytica, has a more beneficial effect on the gut microbiota than the use of Yarrowia lipolytica alone. The combined use of a probiotic with a yeast, particularly Yarrowia lipolytica, has a more beneficial effect on the gut microbiota than the use of Yarrowia lipolytica alone.