April 29, 2021

Interpretive Summary: The use of live yeast to increase intake and performance of cattle receiving low-quality tropical forages

Interpretive Summary: The use of live yeast to increase intake and performance of cattle receiving low-quality tropical forages

By: Anne Kamiya, MS

During the dry season, digestibility of tropical forages decreases. Reduced digestibility subsequently results in poor performance. Supplementation of cattle feed with live yeast (LY) may potentially ameliorate this problem. Live yeast is an area of interest for study as these microbes have the potential to increase digestibility by changing rumen conditions to become more efficient at breaking down fiber.

Researchers fed cattle high fiber, low-quality Rhodes grass hay and supplemented feed with LY to evaluate digestibility in this recent Journal of Animal Science study. Two separate experiments were conducted—a metabolism study and a growth performance study. In the metabolism study, total fecal collection was used as a marker for digestibility whereas in the growth performance study, indigestible neutral detergent fiber (NDF) was the marker. The type of yeast used was Saccharomyces cerevisiae CNCM I-1077.

Growth performance, body weight and rumen fluid were measured periodically. In the first experiment, total tract digestibility was unchanged based on LY intake. Of all the variables studied, only the intraday variation of rumen bacteria was reduced and NDF intake increased. In the second experiment, NDF, ADG, body weight and feed efficiency did not change when LY was added to feed. There was a tendency to increase, but it was not statistically significant. 

Overall, the results of this study are inconclusive but suggest there may still be potential for LY to improve the digestibility of low-quality tropical forage. More in-depth studies using different or multiple types of LY or a combination of LY and bacteria might be more fruitful in elucidating ways to increase the digestibility of low-quality tropical forage.

The original article, The use of live yeast to increase intake and performance of cattle receiving low-quality tropical forages, is available on the Journal of Animal Science website.