Lallemand’s probiotic yeast, Saccharomyces cerevisiae boulardii CNCM I-1079, has gained a new authorisation for use as a feed additive in calves, other young ruminants and Camelidae, across Great Britain.
The live yeast strain, sold under the brand name ProTernative, belongs to the boulardii variety of Saccharomyces cerevisiae, which has more than 60 years of efficacy and research documentation related to gastrointestinal health in humans and monogastric animals.

Mark McFarland, feed additive product manager at Lallemand Animal Nutrition, says ProTernative stands out from the company’s existing rumen-specific live yeast, Levucell SC, as its mode of action is specific to the lower gastrointestinal tract.
“In young ruminants, where the rumen is not yet developed, the lower gut plays a vital role in terms of both digestion and immunity,” he explains.
“The association between a healthy gastrointestinal tract and animal performance is very clear, especially in youngstock.”
He adds: “Youngstock with diarrhoea or any other type of digestive challenge will have lower average daily liveweight gains and typically higher veterinary treatment costs, as they are more susceptible to respiratory disease and other illnesses.”
Mr McFarland says good gastrointestinal health in ruminants is reliant on three distinct pillars – the microbiota in the rumen, associated to the gut epithelium; the gut epithelium itself; and the mucosal immune system.
“The mode of action of Saccharomyces cerevisiae boulardii CNCM I-1079 is totally integrated into all three of these pillars,” adds Mr McFarland.
“It provides key components to control detrimental microbes, while allowing good microbes to flourish, maintain epithelial integrity, and stimulate and balance immune responsiveness.
“The result is a young animal with boosted protection against common challenges, including scours, digestive and respiratory disorders, and weaning stress.”
He says ProTernative is suitable for dairy and beef calves from birth to approximately four months of age, and its inclusion in calf milk replacer formulas can deliver significant benefits.
“Global trial results have demonstrated that calves supplemented with the probiotic daily are better able to cope with digestive stress, with significant reductions in both the number and severity of calf scour cases, respiratory illness occurrence and antibiotic treatments,” adds Mr McFarland.
“ProTernative forms part of Lallemand’s wider youngstock range, designed to help ensure youngstock grow into healthy, productive animals that perform well throughout their lives.”
For more information, please contact Mark McFarland at Lallemand Animal Nutrition on 07827 2228161 or mmcfarland@lallemand.com.