Supplementation of Active Dry Yeast
Direct fed microbial (DFM) products are one possible avenue to improve animal health during the transition period. Active dry yeasts (ADY) are one subset of DFM. ADY have been found to act growth promoters and influence immune function in several species.
Mechanisms
The mode of action for ADY are wide and varied. ADY have been shown to impact lactate and lactic acid production, increase feed digestibility and efficiency, decrease oxygen and improve fermentation and feed breakdown in the rumen.
Benefits
The positive effects of feeding active dry yeast are dependent on diet, formulation, and concentration, and can vary from farm to farm. The documented benefits are listed below.
- In beef steers, feeding ADY showed an improvement in immune response via an increase in TLR-4 expression.
- In the lower gut ADY may inhibit pathogen growth, stimulate an immune response, and balance microbial growth.
- S. cervesiae boulardii has been found to have protective effects on the small intestine in calves and reductions in pathogen load. Ultimately reducing inflammation.
- Improved milk yield and decreased body losses in the first 7 weeks of lactation, without impacting dry matter intake (DMI).
- Protection of the lower gastrointestinal tract.
- Increased crypt depth and width in calves.
- Improved tight junction structure and mucin production.
- Improved innate immune response.
- Improved nutrient digestibility
Phenotypes
Yeast phenotypes are diverse and encompassing. The S. cervesiae family alone includes at least 74 phenotypes grouped into 10 different categories. In ruminants, different strains of S. cerevisiae can change the rumen fermentation profile to a more acidotic and glucogenic state, and/or impact fiber digestion.
It is still unsettled whether S. boulardii is a substrain of S. cerevisiae or a separate species all in itself. Either way, S. cerevisiae boullardii (SCB) is known to impact intestinal mucosa, modulate immune response, gene expression, and protein synthesis.
An activated immune response increases energy demand up to 55%, the equivalent to 1 kg (2.2) lbs. of glucose in a 12 hour period of time. Alterations made by SCB to the immune response may result in energy savings that would leave more glucose available for growth and without increasing DMI. More research is needed to fully understand the mechanisms of metabolism while feeding SCB or other strains of ADY, but in the short term we are seeing benefits to animal health and production so supplementation may become a more popular avenue in improving animal health and maximizing production. For more information on how we utilize ADY and SCB please email us at service@microbasics.com.
Written by: Mariah Gull, M.S.