
Table of Content
- Overview of Yeast and Its Derivatives
- Nutritional Benefits of Yeast in Animal Feed
- Types of Yeast Derivatives Used in Animal Feed
- Benefits of Yeast in Different Animal Species
- Conclusion
- References
Yeast and its derivatives or by-products are essential in animal feed and nutrition. They have garnered attention due to their functional, nutritional, and health benefits. Yeast is a microorganism with a rich source of proteins, vitamins, minerals, and bioactive compounds that enhance animal health, growth, and productivity in poultry, livestock, pets, aquaculture, and big animals (camels and horses).
This article explores the various kinds of yeast and its derivatives in animal feed and formulations. We will discuss the mode of action, the benefits of yeasts and their by-products for different animal species, and factors influencing their effectiveness.
Overview of Yeast and Its Derivatives
Yeast, particularly Saccharomyces cerevisiae, is a single-celled fungus with wide animal nutrition applications for various species. It is a rich source of protein, B vitamins, amino acids, and polysaccharides such as Mannan oligosaccharides and beta-glucans. Yeast derivatives like yeast extract, active and inactive yeast, and others offer a concentrated source of these bioactive compounds and nutrients.
The derivatives of yeast extract are obtained by breaking down yeast cells, making the nutrients highly digestible and readily available for animals. The derivatives serve various purposes, such as improving growth & development rates and boosting gut health and immunity.
Nutritional Benefits of Yeast in Animal Feed

The key goal of yeast in animal feed or formulations is a balanced and rich nutrient profile. Yeast’s key nutrients are essential amino acids, high-quality protein, minerals, vitamins, and other bioactive compounds like MOS and Beta-glucans, which support key physiological functions in animals. Various nutritional components are discussed below:
-
Protein Source
Yeast is a source of protein offering between 40 to 50 % crude protein on a dry matter basis. The protein in yeast has all the essential amino acids that various animal species need, such as lysine, methionine, and threonine. This makes yeast and its derivatives an excellent supplement to animal feed, especially for monogastric animals like poultry, pigs and aquaculture species.
Yeast’s high protein content enables it to complement or replace other protein sources in animal diets, such as fishmeal or soybean oil when the ingredients are too expensive or in short supply. The digestibility of yeast protein is high, leading to better nutrient absorption and utilisation in animals.
-
Vitamins and Minerals
Yeast is rich in B vitamins, such as B1, B2, B3, B5, B6, folic acid, and biotin. These vitamins are essential for energy metabolism, skin health, nervous system function, and overall growth. It also contains trace minerals, such as manganese, zinc, and selenium, that play significant roles in antioxidant activity, enzyme function, and immune system support. Zinc is essential for skin and coat health, and selenium is necessary for neutralising oxidative stress in the body.
-
Beta-glucans and Mannan-oligosaccharides (MOS)
The yeast cell wall has complex carbohydrates like MOS and Beta-glucans, providing various health benefits. Beta-glucans have immune-modulating properties and support to boost immunity and boost immune response by stimulating immune cells to improve disease resistance and overall health.
MOS has a prebiotic function and is beneficial for promoting growth and gut health while inhibiting the activity of pathogenic microorganisms. Further, it helps to maintain healthy gut microbiota, improving nutrient absorption and reducing the risk of intestinal diseases.
Types of Yeast Derivatives Used in Animal Feed

Many yeast derivatives are used in animal feed. The derivatives are essential because of their concentrated nutritional content and bioactive compounds that are bioavailable and digestible to animals.
1) Yeast Extract in Animal Nutrition
Yeast Extract is a digestible and nutrient-rich product derived from yeast cells. It is an excellent source of peptides, amino acids, bioavailable proteins, and vitamins. Yeast extract increases feed palatability, growth performance, and nutrient uptake. The bioactive compounds support gut health by improving nutrient absorption and microbial populations. Further, yeast extract is rich in nucleotides and vital for immune system enhancement and cellular repair.
Hence, this is an essential ingredient for improving the productivity and health of livestock and aquaculture. Yeast extracts are commonly added to animal feeds to improve palatability and stimulate feed intake, especially in poultry, swine, and pets.
2) Inactive Yeast in Animal Nutrition
The yeast cells are treated with heat to deactivate their metabolic activity. Yeast is an essential ingredient for animal feed, containing beta-glucans, proteins, and mannan oligosaccharides. These bioactive compounds improve gut health by boosting immunity, binding pathogens, and supporting a balanced gut microbiota.
3) Active Yeast in Animal Nutrition
Active Yeast has yeast cells sourced from Saccharomyces cerevisiae strains and is widely used as a probiotic in animal feed. It increases digestive efficiency by improving the fermentation of ruminants’ fibres and optimising gut microbial balance in monogastric animals. It further decreases pathogens inside the intestine, enhances nutrient utilisation, boosts immunity, and helps to improve animal performance.
4) Yeast-Based Fermentation Products
Yeast fermentation products are incorporated into animal feed to improve digestion and nutrient absorption. The process yields many beneficial vitamins, enzymes, and other bioactive compounds. Yeast fermentation of feed ingredients may break down complex proteins and carbohydrates, making nutrients accessible to animals.
Yeast-based fermentation is beneficial, especially for ruminants, as it improves rumen fermentation efficiency. The yeast fermentation supports fibre breakdown and makes it challenging to digest feed components, resulting in better overall growth and feed conversion.
Benefits of Yeast in Different Animal Species

Using yeast and its derivatives in animal feed benefits different species, including ruminants, poultry, swine, pets, and aquaculture. The species benefit from yeast supplementation based on their physiological characteristics and nutritional requirements.
1) Poultry
Yeast is widely used to improve growth performance, immunity, and egg production. Its top-quality B vitamins, protein, and essential amino acids are necessary for egg formation and muscle growth. Yeast improves feed conversion rates, increases overall productivity, and stimulates appetite.
The prebiotic effects of MOS in yeast support the gut by promoting beneficial gut flora and preventing the colonization of pathogenic bacteria. It leads to better digestion, improved disease resistance, and reduced mortality in poultry. Yeast-derived products have also been shown to improve the immune response in poultry, making them less susceptible to infections such as Salmonella or E. coli.
2) Pets
Yeast enhances the palatability of pet food, supports overall health, and improves digestion. Its immune-boosting attributes protect pets from infections, while Vitamin B content enhances skin and coat health. Yeast is also essential for ageing pets, supporting metabolic health and maintaining energy levels. Yeast-based products offer additional support to the immune system in dogs and cats.
3) Ruminants
Yeast supplementation improves rumen fermentation in ruminants. The yeast products enhance the activity of rumen microbes, which break down fiber and produce volatile fatty acids, the primary energy source for ruminants. The improved rumen fermentation results in better feed efficiency, improved growth and development rates in cattle, and high milk yield. It further helps to maintain healthy rumen microbiota and reduces digestive disorders (bloating and acidosis).
4) Aquaculture
Yeast and its derivatives are effective in aquaculture for improving growth rates, immunity, and disease resistance in shrimp and fish. Yeast and its products offer essential amino acids, vitamins, and trace minerals critical for optimal growth and health.
Yeast also improves gut health by promoting beneficial gut flora and reducing the load of harmful pathogens. Yeast supplementation has enhanced feed conversion and disease resistance in some aquaculture species, such as salmon and tilapia.
5) Swine
Yeast is beneficial during weaning, a stressful period that negatively affects the feed intake and gut health. Yeast autolysates and extracts stimulate appetite and feed intake, while MOS and beta-glucans improve nutrient absorption and gut health.
Yeast supplementation has improved growth rates, feed conversion ratios, and overall health in pigs. Additionally, yeast helps maintain healthy gut microbiota, reducing the risk of gastrointestinal diseases and improving immune function, leading to better overall performance.
Conclusion
Yeast and its derivatives are valuable animal feed components, offering various nutritional and functional benefits. From enhancing protein quality, improving gut health, boosting immunity, and supporting overall growth, yeast plays a key role in modern animal nutrition. Its diverse applications across various species—poultry, pigs, ruminants, aquaculture, and pets—highlight its versatility and effectiveness as a feed ingredient. As the demand for sustainable and efficient animal production continues to rise, yeast and its derivatives are poised to play an even more significant role in supporting animal health and productivity.
References
- https://www.researchgate.net/publication/374068102_EFFECTS_OF_DIETS_WITH_INACTIVE_DRY_YEAST_ADDITION_ON_PRODUCTIVITY_AND_HEALTH_STATUS_IN_DAIRY_COWS
- https://www.mdpi.com/2309-608X/8/11/1191
- https://www.sciencedirect.com/science/article/pii/S105661712300017X
- https://www.sciencedirect.com/science/article/abs/pii/S0377840117308398