Information on Feed Yeast

The origins of yeast use by humans are lost in time. It is well-known that yeast has long been used in human nutrition (bread, beer, wine, and spirits production). Additionally, baker’s yeast or brewer’s yeast, scientifically known as *Saccharomyces cerevisiae*, is used worldwide in laboratories as a „test subject” to develop biotechnological methods that can later be applied to more complex organisms, including humans.

This approach not only removes the polluting effects of waste but also generates yeast biomass, which can successfully be used in animal and even human nutrition

Preventing Intestinal Problems in Humans and Animals

Since the early 1990s, a subspecies of yeast used in the alcohol industry (*Saccharomyces cerevisiae*) has been selected and applied to prevent and treat intestinal conditions that cause diarrhea in humans and other monogastric mammals. By the late 1990s, researchers discovered that this yeast species could irreversibly bind to pathogenic bacteria in the intestines, such as enterohemorrhagic *Escherichia coli* or *Salmonella typhimurium*, which has mutated multiple times and become resistant to a wide range of antibiotics, posing a serious threat to farm animals.

A Major Role in Enhancing Production in Ruminants

Studies show that adding live *Saccharomyces cerevisiae* yeast to dairy cows’ diets increases beneficial cellulose-digesting bacteria in their rumen, improving cellulose and crude protein digestibility.

Gastrointestinal infections are common in calves during the first weeks of life, especially those caused by *Salmonella* species and *Escherichia coli*. Acute diarrhea during this period can severely impact calf performance.

Recent studies have shown that adding live yeast (*S. cerevisiae*) to milk replacers for calves improves their health and performance by reducing the incidence of diarrhea. Other research has demonstrated that adding this yeast species to calves’ diets eliminates antibiotic-resistant pathogens from their intestines. Additionally, live yeast supplements in ruminants stimulate a specific group of rumen microorganisms, directly contributing to increased productivity in these animals.

It is known that various types of microorganisms coexist in the rumen of polygastric animals, aiding in feed digestion. Any imbalance in this ruminal microflora can trigger nutritional issues and, consequently, reduce production levels.

These imbalances can occur with diet changes, medication, bacterial infections, or stress factors (grouping, changing shelters, transportation, etc.).

Specifically selected live yeast cultures can prevent or even restore these ruminal (and intestinal in monogastric animals) microflora imbalances. Experiments have demonstrated that live yeasts stimulate cellulose-digesting, starch-digesting, and lactic acid-consuming bacteria in the rumen while inhibiting lactic acid and other organic acid-producing bacteria, whose accumulation can lead to acidosis, adversely affecting animal health.

Experiments with young bulls have also shown that ruminal ammonia levels dropped by over 50% when they were administered live yeasts. In this case, ammonia is used for protein synthesis, improving the animal’s performance.

Such scientific results have been recorded worldwide on farms with different feeding practices.

Feedback from farmers indicates that adding yeast to ruminants’ diets leads to better feed conversion, fewer digestive problems, improved animal health, and better productivity performance.

Source: Industrial Waste for Feed Use – Article published in *Ferma* magazine, issue no. 1(33)/2005