Preventing Scours: How yeast can help.

Scours remain the leading cause of death in calves; 57% of calf deaths are due to scour, often in calves under one month old¹.

Even on the best-managed farms, the pathogens that cause scours are present and ready to infect vulnerable animals at their earliest opportunity. The more days a calf is scouring in their first month of life, the less weight they gain; over 15kgs difference by 77 days of age has been reported compared to calves without scours².

The old adage that prevention is better than cure is certainly true when it comes to avoiding scours. But external hygiene alone is not enough—internal immunity must be strengthened. While colostrum management is paramount to building immunity from birth, nutritional supplements can also help.

Yeast based products, including Refined Functional Carbohydrates™ (RFCs™), improve gut health and enhance resilience to stressors. These RFC compounds are naturally present in all yeast cells, specifically the yeast cell wall, but are tightly bound and therefore not readily bioavailable. Additional refinement is needed to render these compounds useful when fed to animals.

The type of manufacturing process used to refine the yeast cell wall has a huge impact on the size and structure of RFCs, which in turn, affects their bioavailability and functionality. The RFCs occur thanks to proprietary enzymatic hydrolysis of the yeast cell wall. Using enzymes to refine the yeast cell wall leads to consistent fractions of the different RFCs that have a large surface area.

Alternative manufacturing processes, such as those using harsh chemicals to hydrolyze the yeast cell wall fragments, fail to produce consistent particle sizes and thus surface area is compromised.

Some of the modes of action of RFCs include:

• MOS supports growth of beneficial bacteria like Lactobacillus and Bifidobacterium.
• MOS and Mannose: Bind bacterial pili (E. coli, Salmonella).
• Beta-glucans:
  • Beta 1-3 glucans bind mycotoxins, neutralizing them.
  • Beta 1-6 glucans prepare immune cells for a rapid response.
• Other RFCs: Block protozoa (Eimeria, Cryptosporidium) from attaching to the intestinal wall.
• Yeast culture: Provides the developing rumen with yeast metabolites, including organic acids, amino acids, nucleotides, enzymes, vitamins (B-complex) and minerals.

Proof of Performance

Pathogen Risk

Pathogenic challenges are difficult to predict; feeding RFCs can provide an initial defense when these challenges occur by reducing bacterial shedding, lowering the risk of disease spread.

An on-farm study on two Wisconsin dairies compared calves fed CELMANAX to controls. Calves were individually housed for six days, then group-fed until day 56³.

Results

• Lower prevalence of Salmonella and rotavirus (p<0.05).
• RFC-fed calves were 2.5kg heavier at 50 days.

Reduced Impact of Stress

Young animals face a number of stressors in early life, such as disbudding, weaning and in some cases, transport. Increased levels of stress can damage the intestinal barrier function, allowing harmful pathogens to colonize the gut and lead to greater risk of scour, which in turn activates the animal's innate immune response. When an animal has an inflammatory response, their immune system is working harder than necessary, using valuable energy that could otherwise be used for growth.

Managing inflammation via feeding of RFCs was explored with commercial Angus heifers fed CELMANAX for 60 days before undergoing a transport challenge on day 62/63⁴.

Results

• Both C. perfringens and total E. coli counts were decreased (p=0.036) in CELMANAX fed heifers compared with control heifers 24 hours after the start of the transportation challenge.
• Salmonella prevalence was decreased (p=0.003) in CELMANAX fed heifers (38.9%) compared with control heifers (50.0%) during the transportation challenge.
• Proinflammatory immune markers IFN gamma and IL-8 were decreased (p<0.001) in CELMANAX heifers compared with control heifers during the transportation challenge.

A university study investigated weaned steers fed CELMANAX during a preconditioning phase (started 14 days after weaning), transported on day 30 to a receiving feedlot and resumed CELMANAX supplementation from days 31 to 69 after weaning (receiving phase)⁵.

Results

• During preconditioning, BRD incidence was lower (p=0.03) in the CELMANAX steers compared to control.
• During feedlot receiving, average daily gain (P=0.07) and feed efficiency (P=0.08) tended to be greater in CELMANAX fed steers vs control, whereas dry matter intake was similar among treatments.

Long-term Impact of RFC Supplementation

Hitting target daily liveweight gains and reducing morbidity can have long term impacts. Holstein calves supplemented with CELMANAX for 60 days during the milk feeding phase only were monitored and followed through to the end of first lactation⁶.

Results

• RFC supplementation reduced E. coli loads (p<0.05), improved body weight (days 42–56), and increased starter intake.
• Pre-weaning RFC-fed calves produced 195kg more milk in first lactation, with +13kg fat and +8kg protein.

Conclusions

A lower pathogen risk in dairy calves improves body weight and supports smoother post-weaning transitions, ultimately enhancing first-lactation productivity.

In beef calves, RFC supplementation lowers morbidity, improves feed efficiency, and reduces stress and inflammation. Animals fed RFCs during transport shed fewer pathogens, leading to healthier, heavier cattle at feedlot arrival.

Whether it's rearing replacement heifers or productive beef animals, having resilient calves is the cost-effective route to preventing health challenges before an outbreak, instead of treating sick animals after issues occur.

Instead of stressing over threats, RFCs can help you focus on raising resilient animals capable of facing the day-to-day challenges.

CELMANAX™ is the only yeast supplement to contain RFCs derived from enzymatic hydrolysis. CELMANAX™ is available in both liquid and dry form to feed your calves.

References

1. Cho Y, Yoon K. An overview of calf diarrhea - infectious etiology, diagnosis and intervention. J of Vet Sci 2014;15(1):1–17.
2. Renaud, D. L. C. Rot, J. Marshall, and M. A. Steele. 2021. The effect of Cryptosporidium parvum, rotavirus, and coronavirus infection on the health and performance of male dairy calves. J. Dairy Sci. 104:2151–2163.
3. Raabis, S., J. Ding and T. S. Ollivet. 2017. The effect of CELMANAX SCP on fecal pathogen shedding, health and performance of preweaned Holstein dairy calves. AABP conference.
4. McCarty, K.J., Tipton, J.E., Ricks, R.E., Danielo, J., Thompson, J.S., Block, E., Pratt, S.L. and Long, N.M., 2022. Effects of postweaning supplementation of immunomodulatory feed ingredient on circulating cytokines and microbial populations in programmed fed beef heifers. Journal of Animal Science, 100(1), p.skab367.
5. Silva, L. G. T., R. F. Cooke, K. M. Schubach, A. P. Brandão, R. S. Marques, T. F. Schumaher, P. Moriel and D. W. Bohnert. 2018. Supplementing a yeast-derived product to enhance productive and health responses of beef steers. Animal: 12:1576–1583.
6. Lucey, P. M., I. J. Lean, S. S. Aly, H. M. Golder, E. Block, J. S. Thompson and H. A. Rossow. 2021. Effects of mannanoligosaccharide and Bacillus subtilis supplementation to preweaning Holstein dairy heifers on body weight gain, diarrhea, and shedding of fecal pathogens. J. Dairy Sci. 104:4290–4302.