One essential function of the gastrointestinal tract (GIT) is to digest and absorb nutrients. To accomplish these two tasks, GIT must maintain a selective permeability, letting in the nutrients and maintaining out in the lumen, microorganisms, and toxins. Selective permeability demands maintaining adequate integrity of mucosal tissue. In this context, the challenge in ruminants is more significant than in monogastrics since in ruminants, more gut compartments play essential roles in absorption: upper gut, absorption of energetical compounds (for example, VFA in the rumen), and midgut, absorption of other nutrients (for example, amino acids in the small intestine). To reach our goal of maintaining gut integrity, we must attack the three main enemies of gut health found in contemporaneous beef and milk production systems: subclinical ruminal acidosis, mycotoxins, and intestinal pathogens (Plaizier et al., 2022; Liew & Mohd-Redzwan, 2018; Khalil et al., 2022).

Knowing gut health enemies

These enemies can initiate vicious circles that reduce gut health. Acidosis causes rumen wall lesions which reduces VFA absorption driving rumen pH down in a vicious circle. Mycotoxins impair the adequate turnover of intestinal cells and the adequate function of tight junctions reducing intestinal integrity and favoring toxins absorption in another vicious circle. When pathogens colonize intestinal mucous and start to replicate fast, mucosal integrity is reduced, and even non harmful microorganisms can raise their replication opportunistically, enhancing infectious and pro-inflammatory processes. Farmers, animal scientists, and veterinarians know that multifactorial technics, for instance, animal management, feed management, and diet formulation, must be applied to fight these enemies of gut health. However, it is interesting to note that yeast-based feed additives may help combat these three enemies simultaneously. Concerning vicious circles, the clever way of avoiding these problems is to prevent them from initiating or starting. Therefore, to avoid ruminal acidosis, mycotoxin toxicity, and pathogen-high multiplication in GIT, we must prevent the rise of lactate in the rumen, inactivate mycotoxin, and avoid pathogens adhering to GIT mucosa.

Appling functional yeast-based feed additives to support animal and human health

To avoid ruminal acidosis, controlling or reducing lactate concentration is essential. Some yeast components can support and/or change the microbial population and positively impact the rumen pH control. Regarding mycotoxin toxicity and pathogen control in the GIT, it is crucial to consider the adequate ingestion of yeast cell wall fraction composed by functional bypass β-1-3 and 1-6 glucans and mannan oligosaccharides (MOS). β-glucans can bind mycotoxins and act as immunomodulators (Castro et al., 2021), enhancing the immune responses and helping to protect the gut integrity. The MOS can agglutinate pathogens and carry them out of the GIT until expelling them in feces. These three modes of action were accomplished by autolyzed yeast grown on sugarcane molasses (RumenYeast®): ruminal lactate and pH control, mycotoxin risk mitigation, and pathogen control (Dias et al., 2018a, 2018b; Gonçalves et al., 2017; Delazeri et al., 2023; Table 1).

Additionally, from the studies of Gonçalves et al., 2017 and Delazeri et al., 2023 we can highlight that this yeast-based feed additive can also support food safety by reducing aflatoxin contaminating milk and pathogens contaminating the meat, as demands the concept of one-health. Regarding actual demands, autolyzed yeast grown on sugarcane molasses has interesting characteristics; it is a coproduct of a renewable energy industry, the sugarcane ethanol industry, is easy to stock and manipulate, and plays a vital role in animal health programs that seek to reduce or withdraw antibiotics from diets. Accordingly, with the technical data we presented, autolyzed yeast grown on sugarcane molasses (RumenYeast®) supports gut health by attacking these three enemies simultaneously; it may also be used as a one-health tool since it can mitigate food contamination. It’s plain to see that yeast derivatives can enhance animal performance (Torres et al., 2022). In literature, positive results of yeast-based feed additives are commonly related mainly to improving digestion and rumen health, which in many cases is a mistake, or at least a poor view. Besides the apparent effects of yeast derivatives on animal performance, these effects vary depending on which kind of yeast derivative is being applied and the challenges to digestion and health during the period. Autolyzed yeasts, grown on sugar cane molasses during ethanol production, have shown a practical effect on animal performance that can be explained in significant part by the high levels of functional mannans and β-glucans, molecules responsible for the delivery of health benefits, for instance, as enhancements in gut health. To highlight the effectiveness of autolyzed yeast grown on sugar cane molasses, we can look at the performance data of the trials cited above (Dias et al., 2018a, 2018b; Delazeri et al., 2023), where milk and meat production enhanced by 7.4% and 4.5% respectively (Table 2). In summary, yeast derivatives grown on sugarcane molasses can reduce the negative impact of subclinical acidosis, mycotoxins, and intestinal pathogens, improving gut health and then animal health status and well-being. As a plus, it will help animals in meat and milk production systems to be closer to their genetic potential.

 

Castro EM, Calder PC, Roche HM. β-1,3/1,6-Glucans and Immunity: State of the Art and Future Directions. Mol Nutrition and Food Res. 2021. doi: 10.1002/mnfr.201901071.

Delazeri D, Buzi KA, Neumann M, Rossi PS, Zart T, Garbossa G, Hintz LP, Bertagnon HG. Autolyzed Saccharomyces cerevisiae cerevisiaecerevisiae reduce microbiological carcass contamination in feedlot steers. Semina Ciências Agrarias 2023. https://doi.org/10.5433/1679-0359.2023v44n1p123

Dias ALG, Freitas JA, Micai B, Azevedo RA, Greco LF, Santos JEP. Effects of supplementing yeast culture to diets differing in starch content on performance and feeding behavior of dairy cows. Journal of Dairy Science. 2018a. doi: 10.3168/jds.2017-13240.

Dias ALG, Freitas JA, Micai B, Azevedo RA, Greco LF, Santos JEP. Effect of supplemental yeast culture and dietary starch content on rumen fermentation and digestion in dairy cows. Journal of Dairy Science 2018b. doi: 10.3168/jds.2017-13241. Epub 2017 Nov 2. PMID: 29103715.

Gonçalves BL, Gonçalves JL, Rosim RE, Cappato LP, Cruz AG, Oliveira CAF, Corassin CH. Effects of different sources of Saccharomyces cerevisiae biomass on milk production, composition, and aflatoxin M₁ excretion in milk from dairy cows fed aflatoxin B₁. Journal of Dairy Science. 2017. doi: 10.3168/jds.2016-12215.

Khalil, A.; Batool, A.; Arif, S. Healthy Cattle Microbiome and Dysbiosis in Diseased Phenotypes. Ruminants 2022. https://doi.org/10.3390/ruminants2010009

Liew WP, Mohd-Redzwan S. Mycotoxin: Its Impact on Gut Health and Microbiota. Frontiers in Cellular and Infection Microbiology 2018. doi: 10.3389/fcimb.2018.00060.

Plaizier JC, Mulligan FJ, Neville EW, Guan LL, Steele MA, Penner GB. Invited review: Effect of subacute ruminal acidosis on gut health of dairy cows. Journal of Dairy Science 2022. 10.3168/jds.2022-21960.

Pontarolo GB, Neumann M, Cristo FB; Stadler Júnior ES, Souza, AM, Machado MP, Bonato MA, Borges LL, Bumbieris Junior VH; Silva MRH. Effects of including autolyzed yeast in the finishing of feedlot steers / Efeitos da inclusão de leveduras autolisadas na terminação de novilhos confinados. Semina Ciências Agrarias 2021. doi: https://doi.org/10.5433/1679-0359.2021v42n4p2471

Torres RNS, Paschoaloto JR, Almeida Júnior GA, Ezequiel JMB, Coelho LM, Machado Neto OR, Almeida, MTC. Meta-analysis to evaluate the effect of yeast as a feed additive on beef cattle performance and carcass traits. Livestock Science 2022. doi: https://doi.org/10.1016/j.livsci.2022.104934

By: William Reis, Animal Scientist, Ph.D.
Ruminant Technical Specialist – ICC Animal Nutrition