Arm & Hammer Animal and Food Production

Elevate Calf Health with Refined RFCs

A healthy heifer calf represents the future success of a dairy. But calf health cannot be taken for granted, especially in light of the challenges presented by scours-causing pathogens which occur all-too-commonly on-farm.

The 2007 National Animal Health Monitoring System (NAHMS) for U.S. Dairy reported that 57 percent of weaning calf mortality was due to diarrhea and most cases occurred in calves less than one month old.1 Unfortunately, calf scours is seldom a simple health issue to manage because it is caused by many different pathogens.

What are RFCs?

Refined Functional Carbohydrates™ (RFC™) are a new technology that can help provide animals with a healthy foundation and help them better deal with insults to their system from pathogens and other challenges.

RFCs are the components harvested from yeast cells (S. cerevisiae) using specific enzymes during the manufacturing process. This enzymatic hydrolysis yields MOS (Mannan Oligosaccharides), (1,3-1,6) beta glucans and D-Mannose.

  • MOS supports the growth of beneficial bacteria like Lactobacillus and Bifidobacterium
  • Mannose binds pathogenic bacteria
  • Beta glucans support the immune system and bind mycotoxins
  • Other RFCs prevent certain protozoa from attaching to the intestinal wall and causing disease

These compounds are naturally present in all yeast cells, but are not readily bioavailable. The method of processing used to refine the yeast cells influences the size and structure of these liberated components, which in turn, affect bioavailability and functionality. Research2,3,4 shows that each RFC has a specific mode of action and outcome when fed to livestock.

Bound by RFCs  

RFCs can help maintain gut health and overall animal health. Since health and production challenges can occur at any time, adding RFCs the calf’s diet from birth—and throughout the animal’s life cycle—can help improve immune function. This happens indirectly by preparing it for challenges and directly by providing a defense mechanism for pathogenic bacteria the animal is exposed to.

Since pathogenic challenges are difficult to predict, RFC-feeding can provide the initial defense when these challenges occur. In essence, RFCs bind pathogens, rendering them harmless to the animal. And RFCs act as a prebiotic by feeding the beneficial bacteria of the intestine while blocking sites for attachment by pathogens.

RFCs have been shown to be efficacious when fed to young calves and help reduce scouring caused by Cryptosporidium parvum. RFCs have also been shown to have activity against Eimeria, another scours-causing organism, as well as various types (serovars) of E. coli and Salmonella enterica. These pathogens are those most likely to causes scouring problems on a dairy.

The RFCs bind to the receptors of the Cryptosporidium protozoa (and other pathogens) and prevent it from attaching to the intestinal wall and causing disease. The organisms then pass harmlessly through the digestive system and are excreted. The pathogens remain deactivated, thereby helping to break their life-cycle which helps to reduce the odds of reinfection.

Research highlighted in the chart below (Figure 1) shows that calves fed RFCs recover faster than those that do not receive RFCs.

Figure 1

a,b,c Indicate significant difference (P < 0.05).

RFCs also help negate the negative effects of mycotoxins that sometimes occur in feed. Just as with pathogens, RFCs bind to these toxins—like aflatoxin—and prevent them from being absorbed through the gut and into the blood circulation. The toxins then pass harmlessly through the digestive system and are excreted.

Growth Benefits

RFCs offer additional benefits. Because calves are healthier, they can spend their energy on growth. Since RFCs are removing challenges to the immune system, less energy is being used by the immune system or for fighting a pathogenic infection that causes diarrhea. That leaves more energy available for weight gain and frame size.

As a result, calves partition energy to growth. This may lead to an improvement in calf growth and performance. Research has shown that healthy starts lead to increased weight gain by up to 8 pounds while improving feed efficiency.5-8

Address Underlying Issue First

While RFCs can be a successful partner in improving calf health and performance, no single tool can overcome overwhelming odds.

A Midwest dairy recently found that before they could reap benefits from RFCs, they had to address underlying hygiene and management issues that were holding back their calf program.

The dairy took three important steps prior to including RFCs in calf diets.

  1. It conducted an audit of current feeding practices and hygiene, and confirmed that Cryptosporidia was the dominant pathogen afflicting calves.
  2. Based on its findings, the dairy corrected procedural drift that had slipped into protocols, as well as fixed plumbing and equipment issues.
  3. The dairy then set goals for success, including milk sample bacteria thresholds, disease incidence and treatment levels.

With these actions, the dairy was able to correct underlying factors that were sabotaging successful outcomes. And it defined success so management could continue to make well-informed decisions.

Once these issues were corrected, the dairy was able to take full advantage of the addition of RFCs to calf diets—and realized a 75% reduction in scours incidence within a few weeks of the RFCs. Plus, calves grew faster and showed weight gains of 5 pounds per calf at weaning following the nutrition intervention.


Dairies will never be able to eliminate all bacterial pathogens, but when basic hygiene and management is in place, RFCs help provide a healthy foundation for optimized performance. And that bodes well for the future.

1 Cho Y, Yoon K. An overview of calf diarrhea - infectious etiology, diagnosis, and intervention. J of Vet Sci. 2014 Mar; 15(1): 1–17.

2 Hashim A, Mulcahy G, Bourke B, Clyne M. Interaction of Cryptosporidium hominis and Cryptosporidium parvum with Primary Human and Bovine Intestinal Cells. Infection and Immunology 2006;74(1):99.

3 Nocek J, Holt MG, Oppy J. Effects of supplementation with yeast culture and enzymatically hydrolyzed yeast on performance of early lactation dairy cattle. J Dairy Sci 2011;94:4046-4056.

4 Baines D, Erb S, Turkington K, Kuldau G, Juba J, Masson L, Mazza A, Roberts R. Mouldy feed, mycotoxins and Shiga toxin - producing Escherichia coli colonization associated with Jejunal Hemorrhage Syndrome in beef cattle. BMC Veterinary Research 2011;7:24.

5 Dennis R, Jalukar S. Effect of CELMANAX™ SCP on calf performance when fed in the milk replacer and grower phase. J Anim Sci 2011; Vol. 89, E-Suppl. 1/J Dairy Sci Vol. 94, E-Suppl. 1. Research Bulletin D-72.

6 Research Bulletin D-71: CELMANAX SCP in dairy calf milk replacers.

7 Research Bulletin D-51: CELMANAX Liquid in dairy calf milk replacers.

8 Research Bulletin D-53: CELMANAX Liquid in dairy calf milk replacers.

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