Bridging the gap to post weaning immunity with algae Beta Glucans

Weaning represents one of the most immunologically disruptive moments in a piglet’s life, in our production systems it typically takes place between 21 to 28 days. At this stage, piglets abruptly lose passive protection from maternal antibodies while simultaneously encountering new pathogens, a cereal-based diet, social mixing and environmental stressors. These immune disruptions manifest as diarrhea, reduced feed intake, increased veterinary costs and reduced growth performance during the first 2–3 weeks post-weaning.

β-1,3-glucan of algae origin (Euglena gracilis), Aleta™ (Kemin Europa nv) has been shown in previous studies to provide a targeted solution to support early immune maturation by being rapidly recognized by pattern-recognition receptors on macrophages and dendritic cells, accelerating maturation of the innate immune system, improving pathogen recognition and cytokine and chemokine regulation during the vulnerable post-weaning window.

Studies have helped us understand how β-1,3-glucan can help the piglets bridge the gap to strong immunity in the post weaning period.

In a nursery study using 200 g/t of β-1,3-glucan, piglets showed clear improvements in gut structure and baseline immune readiness. Increased villus height indicated better absorptive capacity and stronger barrier function, while elevated IgA and TNF-α suggested enhanced preparedness of both mucosal and innate immunity, key for navigating the immunity gap immediately after weaning.

Under pathogenic E. coli challenge, β-1,3-glucan’s impact became even more pronounced. When pigs were exposed to E. coli (F18), β-1,3-glucan significantly reduced diarrhea days, strengthened the gut barrier by upregulating tight-junction and mucin genes, and lowered gut permeability. Systemically, pigs exhibited reduced inflammatory and stress markers, fewer white blood cells and neutrophils, lower TNF-α, cortisol, and haptoglobin, indicating faster immune resolution and improved resilience.

What this means for immunity

• Without challenge: β-1,3-glucan primes mucosal immunity (increased IgA) and supports gut architecture (increased villus height), improving first-line defense.
• With an pathogenic E. coli challenge: β-1,3-glucan modulates excessive inflammation while tightening the gut barrier, shortening the functional duration of disease signs (less diarrhea, lower stress/acute-phase markers).

What this means to producers:

• Fewer diarrhea days reduce treatments and labor and stabilize intake patterns—key to batch uniformity.
• Improved villus height and mucosal IgA suggest better nutrient capture and lower pathogen pressure on commercial farms,
• Fewer culls and less slow growers, lower mortality risk, and smaller variation of bodyweight.

Conclusion: β-1,3-glucan accelerates immune maturation and fortifies the gut, helping to control diarrhea under E. coli pressure and improving mucosal readiness, both key for healthier, post-weaning transitions.