This document discusses the use of Saccharomyces cerevisiae yeast in ruminant animals. S. cerevisiae, commonly known as brewer's yeast, has been used for winemaking, baking and brewing. It is believed to have originally been isolated from grape skins. The document outlines different types of yeast used in ruminant feed, including brewer's yeast, yeast metabolites produced during fermentation, and active dry yeast. Several studies are mentioned that found specific strains of S. cerevisiae improved fiber digestibility, feed efficiency, dry matter intake, milk production and fat content in ruminants.

1. Yeast in Ruminants
C.E.O
Eng. Mohammad AlSaleh
info@technicaljo.com
Technical Company for Industry and Trade

2. OUTLINE
-Introduction.
-Objective.
-Type of Yeast.
-The effects of various probiotic yeast
strains on ruminant performance.

3. INTRODUCTION
A long cherished dream of ruminant nutritionists has been to
manipulate and improve the efficiency of ruminal fermentation.
Research is continued to find a sole feed supplement that can
improve the rate, efficiency and/or quality of gain, production,
reproduction, to prevent certain diseases or preserve feeds.
One such class of these compounds is Saccharomyces cerevisiae.

5. Saccharomyces cerevisiae is a species of yeast. It
has been instrumental in winemaking, baking,
and brewing since ancient times. It is believed to
have been originally isolated from the skin
of grape.

6. OBJECTIVE
Highlight about Saccharomyces cerevisiae in
Ruminants.

7. TYPE OF YEAST
Brewer’s Yeast
Brewer’s yeast is a by-product from the breweries.
Brewer’s yeast is obtained by the removal of yeast after
the brewing process and subsequent inactivation by
means of organic acids.

9. The yeast by-product is not live and offers no
functional properties beyond its nutritional profile.
Brewer’s yeast is used as a flavoring ingredient in the
food industry, and as feedstuff for pigs, ruminants,
poultry and fish. Brewer’s yeast is mainly a source of
protein, vitamins and minerals.

11. Yeast Metabolites
Yeast Cultures are produced during anaerobic
fermentation of Saccharomyces cerevisiae.
The bioactive components are the metabolites produced
during fermentation. Most residual yeast cells are killed
in the process.
The purpose of fermentation is the production of
extracellular metabolites by the yeast cell.

13. There are three groups of biochemicals we are
interested in: compounds that affect the taste of the
feed (palatability factors), the smell of the feed, and
those that stimulate bacterial growth in the digestive
tract (nutritional metabolites of nutrilites).
It is the later that appear to provide the performance
attributes associated with this class of yeast.

14. Active dry yeasts (ADY)
The most common ADY species used in the feed industry is
Saccharomyces cerevisiae and guarantee a live coliform
unit per gram (CFU/gm)In regard to the mode of action
most suppliers lean towards oxygen scavenging as their
primary selling point.

16. For microbes to survive in the rumen they require an
aerobic environment.
As the yeast grows it creates a more hospitable
environment for microbe life. Adding live yeasts to the
rumen are intended to utilize this oxygen for their
metabolism.
Once the oxygen is removed, the rumen bacteria attach
efficiently onto the fiber particles and digest the forage.
The extent somewhat depends on the exact strain of the
yeast and the rumen condition.

18. There is a significant amount of research indicating that
ADY improve performance of dairy cows in defined
controlled trials, whatever the mode of action.
People question if live yeasts can in fact survive the harsh
acidic environment of the rumen and that delivering
viable units effectively in the field is compromised.

21. THE EFFECTS OF VARIOUS PROBIOTIC YEAST
STRAINS ON RUMINANT PERFORMANCE
Saccharomyces cerevisiae, QAU03
•Increase fiber digestibility and improve milk and
its fat contents.
•Improve gastrointestinal tract microbial balance.

22. Saccharomyces cerevisiae Yea-sacc 1026
•Improved feed efficiency.
•Yeast culture increased dry matter digestibility.
•Positive effect on DM, NDF, ADF, and hemicellulose
digestibility.

23. Saccharomyces cerevisiae CNCM l-1077
•Enhanced rumen fermentation.
•Lower CH4 emissions.
•Decreased time spent in subacute rumen acidosis.

25. Saccharomyces cerevisiae SC 10 ME
•Lower the risk of rumen acidosis.
•Increased fiber degradation of low quality maize
silages.

26. Thanks