All animals are born without an adaptive immune system in place, it must be developed from scratch. It should be noted that most aquatic species only have the innate immune system to protect them from foreign invaders. With these challenges in mind, researchers have been evaluating how ß-glucans in the diet can support young animals’ immunity and resilience.
Product Manager
Selko Global
All livestock and aquaculture production species are exposed to challenges that may subsequently affect their health and performance. Immune competence is a common denominator among resilient livestock and aquaculture species.
As scientists learn more about the effects that different molecules exert on animals’ immune status, attention is focusing on how beta-glucans (ß-glucans) in feed additives may support animals’ immunity. Below, we consider the importance of establishing an immune competent status early in life and look at how ß-glucans in the diet may influence an animal’s immunity. Going beyond theory, we share results from scientific trials involving chickens, swine, calves and aquatic species that evaluated a feed additive containing specific ß-glucans.
WHY IS IT SO IMPORTANT TO SUPPORT YOUNG ANIMALS’ IMMUNE SYSTEMS?
All animals are particularly vulnerable during the first few weeks/months of life when their immune system is not fully developed. Consider that a broiler chicken’s immune status requires 4-6 weeks to fully develop. Given that in most production regions chickens are harvested at 5 weeks of age, a bird may never achieve a fully developed immune system. A similar delay in achieving full immune status is observed in post-weaning piglets and calves.
INNATE AND ADAPTIVE IMMUNE SYSTEMS
When we talk about an animal being immune competent, we are considering more than the innate (non-specific) immunity that is present at birth/hatch. The adaptive (specific) immune system develops to help the animal fight targeted pathogens and remember them so that antibodies can respond in case of a new infection with the same or a similar pathogen.
Because all animals are born without an adaptive immune system in place, it must be developed from scratch. It should be noted that most aquatic species only have the innate immune system to protect them from foreign invaders. With these challenges in mind, researchers have been evaluating how ß-glucans in the diet can support young animals’ immunity and resilience.
HOW DO BETA-GLUCANS SUPPORT THE HEALTH OF YOUNG ANIMALS?
ß-glucans are a diverse group of molecules that can be found in plants, the bran of cereal grains, certain fungi and bacteria and in yeast cell walls. Each source provides a different type of ß-glucan. In general, there are four different types of ß-glucans: ß 1,3-glucans, ß 1,4-glucans, short ß 1,3/1,6-glucans and long ß 1,3/1,6-glucans. They all have different effects due to their distinct molecular structures. The ß 1,3/1,6-glucans have a 3D structure, compared to the ß 1,3, and 1,4-glucans that have a 2D structure.
Long ß 1,3/1,6-glucans help young animals in challenging health circumstances by activating the very first line of defense of the innate (non-specific) immune system. The activated immune system can then initiate the adaptive immune response to fight the pathogen. The perfect fit of the ß glucan structure into the receptors of the innate (non-specific) immune cells is crucial for the activation of the adaptive immune system. A slight deviation of the 3D structure (for example, damage) will limit the capability of activation.
UNDERSTANDING THE MODES OF ACTION
Research on the role of ß 1,3/1,6-glucans in supporting immunity led to the development of Selko® Fibosel®, a feed additive developed to strengthen the developing immune system and boost young animals’ natural defense mechanisms. Fibosel is composed of long ß 1,3/1,6-glucans from the yeast strain saccharomyces cerevisiae. This specific yeast strain is known for its effect on the immune system in humans and animals. The long ß 1,3/1,6-glucans present in the yeast cell wall are covered by a layer of non-digestible short chain branched carbohydrates known as mannan oligosaccharides (MOS). This layer of coverage prevents the long ß 1,3/1,6-glucans from reaching the macrophages’ receptors. To remove the MOS layer, the feed additive uses natural enzymes to cut openings in the MOS layer. This action exposes the long ß 1,3/1,6-glucans, without damaging their important 3D structure. Fibosel is the only product that uses enzymes to separate the MOS from the long ß 1,3/1,6-glucans.
ACTIVATING THE INNATE IMMUNE SYSTEM TO BOOST YOUR VACCINATIONS
An activated non-specific immune system creates faster and greater immune responses. The communication between non-specific and specific immune cells is driven by cytokines. Activated non-specific immune cells like macrophages send out more cytokines and this action leads to an increase in antibody titers. We performed a study that shows a 20% higher antibody titer in broiler chickens 4 weeks after the Gumboro vaccination was given. Below, we provide a glimpse into several studies evaluating Fibosel’s effects on different species.
FIBOSEL IN BROILER CHICKENS
Selko has performed four scientific studies with Fibosel included in the diets of broiler chickens. Given that scientific facilities are usually much cleaner than commercial facilities, the birds’ health was challenged by limiting cleaning in the barn. All four studies showed an improved feed conversion ratio and reduced mortality in the chickens that received Fibosel.
FIBOSEL IN SWINE
Two scientific trials were performed to assess the effect of Fibosel in swine. The study in weaned piglets showed a decreased severity and duration of diarrhea and an improved the daily gain and feed conversion ratio among animals receiving Fibosel. In the second study, Fibosel was provided to lactating sows and results showed higher immunoglobulin levels in the sows’ milk. In addition, sows’ piglets showed a higher survival rate and higher litter weight gain.
FIBOSEL IN CALVES
A series of scientific trials was done in dairy calves. Fibosel included in the milk replacers fed to calves was shown to improve both average daily gain and the feed conversion ratio. The calves were fed with Fibosel containing milk replacers for 12 weeks.
FIBOSEL IN AQUATIC SPECIES
Fibosel is a very interesting feed additive for aquatic species. As fish and shrimp have only the non-specific immune system to protect them from foreign invaders, activation of this system during challenging periods in their lives supports their immune responses to pathogens. Fibosel was studied in shrimp post-larvae 25 days and in Atlantic salmon (start bodyweight of 22.7 g). in both studies the animals were infected with Vibrio. Fibosel was shown to improve survival rates in both cases.
Delivering naturally exposed long ß 1,3/1,6-glucans can make animals more resilient by boosting their natural defense systems, helping protect against harmful pathogens and increasing the efficacy of a vaccination program. As part of an integrated feed, farm and health management program, this feed additive can support immune competence at a time when regulations are increasingly restricting antibiotics for non-therapeutic use.
About Sanne van Beers
Sanne van Beers holds a Master’s degree in Animal Sciences from Wageningen University in The Netherlands. After which she joined Trouw Nutrition as swine gut health researcher. After 5 years in the research and development department of Trouw Nutrition she moved into a commercial role as product manager in Selko being responsible for technical support of Fibosel® and TNIBetain.
