Live yeast benefits in peripartum: from the rumen to the udder

The transition period around calving is one of the most challenging times in the production cycle of ruminants. If not managed properly, it can lead to performance and health issues, such as metabolic disorders, loss of milk production, or poor body condition. Moreover, a newborn’s performance and health status also rely on the dam’s performance. A research project on the link between rumen function and maternal performance was conducted in partnership with Université Clermont Auvergne and INRAE, UMR 454 MEDIS, in Clermont-Ferrand.¹ It complements previous findings on the effects of LEVUCELL SC in transition.²

Stabilizing the rumen microbiota

Two groups of gestating ewes (n=14 for each group) were fed either a control diet or a ration supplemented with the live yeast Saccharomyces cerevisiae CNCM I-1077 (LEVUCELL SC) during the last month of gestation.
As in the previous studies², metagenomic analysis was conducted on the rumen microbiota:

• The deleterious effect of parturition on fibrolytic bacteria populations was
  highlighted.
• The activity of the specific live yeast in the rumen alleviates these changes in the supplemented animals: the fibrolytic microbial populations in the rumen are stabilized around parturition.
• As a result, rumen fermentation was also maintained with steady VFA concentrations.

Improved colostrum quality

The live yeast-supplemented ewes showed significantly higher IgG concentrations in their colostrum when compared to the control group, which ensures improved immune transfer to the lambs. Indeed, newborns from the supplemented dams showed higher IgG levels in their blood at birth and at one week of age (Figure 1). There was also a higher concentration of the bioactive antimicrobial molecules lactoferrin and sialic acids in the colostrum, which could also benefit the robustness and digestive system development of newborns.

Figure 1: Effect of ewe dietary supplementation on colostrum and lamb serum IgG levels

More robust lambs

The benefits for the lambs are two-fold:

1. Better immune protection through the colostrum, and
2. Average heavier birth weights (+327g, on average), probably thanks to the improved diet utilization during late gestation.

In conclusion, feeding live yeast to gestating ruminants supports fibrolytic populations in the rumen and helps extract more energy from the diet. These effects in the dam rumen are reflected in the udder, with higher IgG levels in the colostrum, which are positively transferred to the newborn lamb, improving the robustness of the lambs.