PERSPECTIVES: Tackling Presence of Beta-Mannans in Feed Could Unlock Sizeable Gains for Industry—Elanco (1)

11 May 2020- Over the last few decades, some of the most important improvements in animal nutrition have come from better understanding—and then dealing with—the anti-nutritional factors in widely-used feed ingredients. As enzymes such as phytase and xylanase have come into near universal use, they have unlocked significant gains in animal health and performance.

Now, Elanco would like to see the same level of attention extended to another antinutritional factor: β mannans. Citing years’ worth of research into the harm these can cause by triggering the defense mechanisms of the innate immune system that cause intestinal inflammation^1,2, Elanco argues that β-mannans are leading to a loss of metabolizable energy of about 90 kcal/kg, reduced flock uniformity^3-9, and higher susceptibility to infections^10,11.  “During periods of increased stress, for example during an acute infection, the β-mannans’ adverse effects increase dramatically, and the productivity loss can even exceed 20%,” claims Karl Poulsen, regional nutritional advisor at Elanco. “When this happens, the β-mannans’ influence on health becomes much stronger, with increased mortality and morbidity¹⁰.”
 
The problem, of course, is that β-mannans are common polysaccharides in plant-based ingredients. To help understand just how widespread β-mannans are in animal feed, Elanco has undertaken a survey to update the reference tables used to determine whether the application of a β-mannanase to break down these ANFs would be appropriate. In the interview below, Mr. Poulsen discusses this work and makes the case for the industry taking the problem of β-mannans more seriously.

[Feedinfo News Service] Why did Elanco decide that a survey of β-mannan content in different feed ingredients was necessary? 

[Karl Poulsen] Elanco recently completed a global survey of the BM content in commonly used feed ingredients.  The survey includes 236 samples of common feed ingredients from 21 countries across the globe.  This makes it the largest β-mannan survey, so far.  An important motivation behind this survey was to update our reference table for β-mannan content in common feed ingredients.  This table is important because our recommendation to use Hemicell is based on the estimated dietary β-mannan content, and the values are included in a convenient mannan-calculator that makes it easy to estimate the dietary β-mannan content and predict if the addition of a β-mannanase will be cost effective.

[Feedinfo News Service] What are the most striking findings from the worldwide β-mannan survey? What did the survey conclude?

[Karl Poulsen] The main outcome of the survey was new information about the soluble β-mannan content in 36 common feed ingredients.  The results did not indicate a correlation between the contents of crude protein or crude fiber and β-mannans, so the β-mannan content in dehulled soybean meal with higher crude protein content is not reduced, and it is not increased in dehulled soybean meal with higher fiber content¹². 

Table 1. Estimated soluble β-mannan content in common feed ingredients

*Estimated Soluble β-mannan, % = Soluble mannose, % x 1.5

[Feedinfo News Service] What is the minimum level of dietary β-mannan needed to affect animal health? Does Elanco have any estimates as to how common of an issue this might be in monogastric diets worldwide (i.e. what percentage of diets include β-mannans above this level?)

[Karl Poulsen] For commercial production conditions, both our trials and experience with customers indicate that a loss of about 3% in production efficiency can be expected when the soluble β-mannan content exceeds 0.2-0.25% and the feed also contains at least 12% of soybean meal and or sunflower meal.  Virtually all diets for standard broiler or turkey production exceeds these criteria for β-mannan content, so it is a very common problem.    

The adverse effects of β-mannans are influenced by two factors:  the dietary β-mannan content is important, but the level of intestinal leakage or inflammation is likely much more important¹³.  We believe intestinal leakage is most important because β-mannans appear harmless in the absence of intestinal leakage or inflammation¹⁵.  There are almost always plenty of challenges in commercial production conditions, so some level of inflammation and leakage is always present.  In vitro studies have indicated that as little as 0.05% β-mannan can cause a strong innate response¹⁶. 

[Feedinfo News Service] Is it reasonable to expect companies to regularly test the β-mannan levels of their feed? When/how regularly should this be done? What other actions does Elanco recommend to control the potential of negative effects caused by β-mannans?

[Karl Poulsen] The assay procedure used to quantify β-mannans in feed ingredients is quite time consuming and also very expensive.  So, even if cost was of no concern, I would not recommend feed companies to do their own analysis, mainly because the batch the samples were taken from most always will have been consumed before the results are available.  The best advice is therefore to continually use the reference table to estimate the dietary β-mannan content and determine if a β-mannanase should be added.  Doing this should be standard practice.  The only other thing companies can do to control the negative effects of β-mannans, is to routinely add Hemicell (β-mannanase) to all feeds with a relevant β-mannan content.

[Feedinfo News Service] Do you think the industry at large has a good understanding of how β-mannans can be problematic? How has interest in this issue evolved since Elanco first became involved in the nutritional sector?

[Karl Poulsen] The understanding of β-mannans influence on animal production continues to improve, but every survey we’ve completed to monitor the awareness about β-mannans continues to identify it as a key hurdle.  Part of our job is therefore to continue to educate about β-mannans’ impact on immunity and animal performance.  Phytase and xylanase were both on the market for many years before their use became standard, and it is realistic to expect a similar development in the use and acceptance of β-mannanase.  We therefore expect to continue investing in research to enhance the understanding of β-mannans’ influence on the immune system and animal production.  The first nutritionists with solid experience using Hemicell have no hesitation recommending to poultry producers that they consider using Hemicell as a standard feed ingredient in the same way that phytase and xylanase enzymes are used.

References:
1. Geniec, N.O., Alei, F., and Klasing, K. 2015. “Effect of Hemicell HT Enzyme on the Immune System of Chickens and their Performance.” International Poultry Scientific Forum.

2. Poulsen, K., Baker, K.T., and Kwiatkowski, T. 2018.  “Effects of β-Mannanase on Intestinal Health Analyzed in 30 Experience from EMEA.” Elanco Animal Health. Data on file.

3. Mathis, G., Greenwood, M., et al. 2007. “Turkey Tom Research Study to Test the Efficacy of ChemGen’s Enzymes vs. Varying Energy Levels, Experiment 010807.” Southern Poultry Research Inc. Data on file.

4. Mathis, G. 2010. “Study No. CGT 10: Comparative Examination of ChemGen Corp. Enzymes Fed to Tom Turkeys.” Southern Poultry Research Inc. Data on file.

5. Knox, A. et al. 2009.  Efficacy of Hemicell®-L and Hemicell-HT in broilers fed on pelleted diets based on wheat and soybean meal.  Roslin-ChemGen broiler trial code 2009/3018.  DoF.

6. Van Eerden et al. 2015. Effects of β-mannanase in broilers on low energy diets.  20th European Symposium on Poultry Nutrition. Poster 079 (ID 229), p 284-286.

7. Pettey, L., Carter, S., Senne, B. and Shriver, J. 2002. Effects of ß-mannanase addition to corn-soybean meal diets on growth performance, carcass traits, and nutrient digestibility of weanling and growing/finishing pigs. J. Anim. Sci. 80: 1012-1019.

8. Mendoza, O.F. et al 2015. “Effect of dietary β-mannanase on the growth performance of growing pigs.” ASAS Midwestern Section and ADSA Branch. J. Anim. Sci. 93: 1.

9. Jackson, M.E. 2013. The Effect of β-mannanase on broiler performance and uniformity. 24th Australian Poultry Science Symposium. pp.92-95 ref.13

10. Hsiao, H.-Y., Anderson, D.M., Jin, F.L., and Mathis, G.F. 2004. “Efficacy of β-mannanase (Hemicell®) in Broiler Chickens Infected with Necrotic Enteritis.” International Scientific Forum, Abstract 120, The Southern Conference on Avian Diseases

11. Vangroenweghe F. and Poulsen K. 2020. Application of Hemicell HT – a β-mannanase enzyme – restores post-weaned piglet performance in the presence of challenging protein sources.  Publication pending.

12. Global Update on β-mannan content in common feed ingredients. 2018. Beta-mannan survey DOF

13. Anderson, D.M. & Hsiao, H.-Y.  New Feed Enzyme Development . ChemGen Corp. 2009, 1: 1-30

14. Couch, J.R., Y.K. Bakshi, T.M. Ferguson, E.B. Smith and C.R. Creger (1967) The effect of processing on the nutritional value of guar meal for broiler chicks. British Poultry Science 8: 243-250.

15. Hung, T.V. & Suzuki, T. 2017. Guar gum fiber increases suppressor of cytokine signaling-1 expression via toll-like receptor 2 and dectin-1 pathways, regulating inflammatory response in small intestinal epithelial cells. Mol. Nutr. Food Res. 61, 10, 2017,

16. Klasing, K.C. et al., 2014. HTLUS130004. Pilot Efficacy Study: Effect of Hemicell HT Enzyme on the Immune System of Broiler Chickens Using and In Vivo and In Vitro Study Techniques. Data on file.

Published in association with Elanco