New meta-analysis sharpens focus on β-mannans in poultry and swine
Bottom line
A new review and meta-analysis in Animals pulls together evidence on how dietary β-mannans can impair gut function and growth in chickens and pigs, and how supplemental β-mannanase may help offset those effects. The paper, published September 26, 2026, argues that β-mannans in common plant-based ingredients such as soybean meal, guar meal, and copra meal can increase digesta viscosity, disrupt intestinal microbiota and nutrient use, and ultimately reduce performance in monogastric species. The authors also report that their chicken meta-analysis drew on 102 observations from 30 studies across 28 peer-reviewed papers, with the goal of giving nutritionists a more interpretable basis for adjusting β-mannanase supplementation to dietary β-mannan content. (mdpi.com)
Why it matters: For veterinary professionals working with poultry and swine systems, the paper reinforces that feed formulation is also a gut health issue. β-mannans have been linked to poorer nutrient digestibility and immune activation in the small intestine, while outside research in nursery pigs and broilers has associated β-mannanase supplementation with improvements in digestibility, intestinal morphology, digesta viscosity, and growth-related measures. In the U.S., β-mannanase is already recognized in AAFCO ingredient definitions, and recent AAFCO meeting materials show additional regulatory activity around new β-mannanase notifications for poultry, underscoring that this enzyme class is moving further into mainstream feed practice. (asas.org)
What to watch: Expect follow-up attention on dose guidance, ingredient-specific responses, and whether newer regulatory clearances and commercial products translate into more routine use in poultry and swine feeding programs. (mdpi.com)
A newly published review and meta-analysis in Animals is putting fresh attention on β-mannans as a persistent nutritional and intestinal challenge in chickens and pigs, and on exogenous β-mannanase as a practical response. Published September 26, 2026, the paper concludes that β-mannans function as anti-nutritional non-starch polysaccharides in monogastric diets, with downstream effects on microbiota, intestinal health, nutrient utilization, and growth performance. (mdpi.com)
The topic isn’t new, but it’s becoming more relevant as poultry and swine diets continue to rely heavily on plant-derived ingredients and cost pressure pushes formulators toward lower-cost raw materials. AAFCO’s official feed ingredient definitions list β-mannanase for use with substrates including corn, soybean meal, guar meal, and copra meal, and describe supported uses such as reducing excreta stickiness in poultry and lowering digesta viscosity in swine diets. That regulatory footing helps explain why the enzyme has shifted from a niche additive discussion to a broader feed management conversation. (aafco.org)
In the new paper, the authors focus on the intestinal-nutritional interface, arguing that the structure and solubility of β-mannans are central to the problem. According to the article summary, highly branched and more soluble β-mannans can raise digesta viscosity, interfere with enzymatic digestion in the small intestine, and negatively modulate intestinal health. The paper also says its chicken meta-analysis used 102 observations from 30 studies across 28 peer-reviewed papers to assess how β-mannanase supplementation affected average daily gain, with the stated aim of giving nutritionists a more direct basis for matching supplementation to β-mannan content in the diet. (mdpi.com)
That framing is broadly consistent with earlier and parallel literature. A recent broiler meta-analysis indexed in PubMed found significant positive effects of dietary β-mannanase supplementation on body weight gain, feed conversion ratio, villus height, digesta viscosity, and several digestibility and energy-use measures. In pigs, an American Society of Animal Science interpretive summary published this year reported that β-mannanase supplementation in low-cost nursery diets mitigated negative effects on intestinal inflammatory markers, nutrient digestibility, and growth performance. Taken together, those findings suggest the new review is less a disruptive reversal than a consolidation of evidence into a more practice-oriented framework. (pubmed.ncbi.nlm.nih.gov)
Industry and regulatory signals also point in the same direction. AAFCO meeting materials from 2025 show a BASF-related GRAS notification for a β-mannanase product for poultry, with FDA listed as having “no questions” on the notice. That doesn’t validate every performance claim, but it does show continued product pipeline activity around the enzyme category. Separately, feed industry commentary has increasingly linked β-mannans to gut inflammation, inefficient nutrient use, and the need to protect performance when using vegetable-based feed ingredients, though those claims should still be weighed against product-specific evidence and formulation context. (aafco.org)
Why it matters: For veterinarians and technical advisers in production animal practice, this is a reminder that feed enzymes sit at the intersection of nutrition, gut integrity, and health management. If β-mannan-rich ingredients are contributing to viscosity, altered microbial ecology, or inflammatory signaling, then β-mannanase can be viewed not just as a performance tool, but as part of a broader intestinal resilience strategy. That matters most in young or stressed animals, especially broilers and nursery pigs, where small changes in digestibility or gut function can quickly show up as poorer growth, worse feed efficiency, or greater downstream health pressure. (mdpi.com)
There are still limits to keep in mind. The new paper is a review and meta-analysis, not a field trial under a single commercial production system, and responses to β-mannanase are likely to depend on ingredient mix, β-mannan load, enzyme source, dose, age, and baseline diet quality. The regulatory record also reflects multiple organism sources and product configurations for β-mannanase, which means veterinary and nutrition teams should be careful about extrapolating results from one product or substrate context to another. (aafco.org)
What to watch: The next step is likely more precise, formulation-level guidance, especially around which poultry and swine diets benefit most, how β-mannan content should be characterized in practice, and whether future trials can tie enzyme use more clearly to health, not just performance, outcomes. (mdpi.com)
Common questions
What do β-mannans do in chicken and pig diets?
The article says they can increase digesta viscosity, disrupt intestinal microbiota and nutrient use, and reduce growth performance in monogastric species.Which feed ingredients are linked to β-mannans?
The article names soybean meal, guar meal, and copra meal as common plant-based ingredients that contain β-mannans.How much evidence did the chicken meta-analysis include?
It used 102 observations from 30 studies across 28 peer-reviewed papers.What was the goal of the meta-analysis?
The authors wanted to give nutritionists a more interpretable basis for adjusting β-mannanase supplementation to dietary β-mannan content.