Algae-based Β-glucan Can Provide Intestinal Immune Enhancement For Piglets
The researchers said that piglets exposed to E. coli could see an improvement in gut health and immune function in algae-derived beta-glucan.
Researchers at the University of California, Davis and Evonik have explored the potential of algae as a platform for the production of beta-glucan (beta-glucan) for piglet diets.
The team published its work in the journal Animal Feed Science and Technology.
"The purpose of this study was to study the effects of algae-derived beta-glucan on diarrhea, intestinal permeability and immune response in experimentally infected F18 E. coli weaned piglets," the researchers said.
They said that the addition of high doses of algae-derived beta-glucan reduced diarrhea throughout the feeding and challenge trials.
Compared with the results of the control diet, feed additives also reduced white blood cells, serum tumor necrosis factor (TNF-α), neutrophils, cortisol and haptoglobin, and affected the expression of several immune linked genes.
"The results of this study indicate that the addition of about 108 mg / kg of β-glucan to animal feed can improve the intestinal barrier function and immunity of weaned piglets, reduce post-weaning diarrhea, and promote the health and safety of weaned piglets. Pork profitability. Producers use antibiotics in feeds are limited," they said.
The β-glucan used in this experiment was the dried alga Euglena gracilis supplied by Algal Scientific, US. The product contains about 50% beta-glucan, 95% of which is beta-1,3-glucan.
Kemin acquired Algal Scientific's beta glucan technology in 2017.
Background on piglet diarrhea and β-glucan use
Researchers say that post-weaning diarrhea is associated with about 20% to 30% of weaned piglet mortality, and producers face huge economic losses.
Therefore, they say that a variety of feed-based products have been developed to address the challenges of diarrhea. Many products focus on regulating the intestinal microbiota or improving the immune response in weaned piglets to improve disease resistance.
They say that β-glucan is a polysaccharide found in grains, algae, algae and fungi.
"The individual glucose in beta-glucan is primarily linked by (1,3)-, (1,4)- or (1,6)-beta glycosidic linkages," the researchers said. "The biological properties of beta-glucan have been reported to include anti-tumor and immunomodulatory effects in vitro."
They said that the effects of beta-glucan on immune enhancement have previously been demonstrated in pigs, mice and humans. But not all types of beta-glucan produce the same immunomodulatory results.
They say that cellulose is beta-glucan, but it does not produce immunomodulatory effects. However, types from fungi and yeast are involved in the regulation of the immune system of animals.
"This change is due to differences in physicochemical properties, including purity, solubility, molecular weight, degree of branching, polymer charge, chemical structure and tertiary structure between these beta-glucans," they said. “In addition, Dectin-1 highly recognizes β-(1,3)-glucan from a variety of sources and therefore triggers regulation of the immune system.”
Why do you want to see algae?
Algae-derived beta-glucan provides immune enhancement
The researchers say that most of the commercially available beta-glucans are currently from yeast.
However, little work has been done on the detection of algae-derived beta-glucans, especially in pig diets.
"The beta-glucan extracted from the algae of Euglena is linked to the (1,3)-glycosidic linkage and is classified as paramylon," they said.
They say that in vitro studies have found that algae-derived beta-glucan enhances porcine leukocyte responses.
"Therefore, the hypothesis of this experiment is that supplementation of algae-derived Euglena-derived beta-glucan can modulate immune response and intestinal integrity and, therefore, enhance the disease resistance and health of weaned piglets," they added.
Feeding and disease challenge details
The researchers said that during the feed and disease challenge, 36 weaned piglets were given one of three diets and infected with pathogenic E. coli.
No diet includes antibiotics, zinc oxide or spray-dried plasma.
They said the diet included a non-supplementary control and trial diet containing two supplemental, commercially produced beta-glucans at a concentration of 54 or 108 mg / kg.
Piglets received diet 5 days prior to disease exposure and were followed for 12 days after the challenge.
They said that piglets were scored diarrhea twice a day and the temperature was checked daily.
The researchers collected blood samples on day 0, day 2, day 5, day 8 and day 12 after exposure to examine blood cell counts and inflammatory markers.
They said that piglets were weighed at weaning one day before the onset of the disease and on days 5 and 12 post-infection.
Feed intake was recorded and average daily feed intake, average daily gain and feed conversion ratio were established.
The researchers said that on the 5th and 12th day after infection, some piglets were collected to collect jejunal tissue and analyze intestinal permeability.
Mucosa from jejune and ileum were also collected.
The researchers said that throughout the experiment, regardless of diet, pig weight, average daily gain, average daily feed intake and feed efficiency remained similar.
However, they said that piglets on low-dose supplemented diets had lower temperatures on days 5 and 7 after infection than other diets.
The addition of high doses of beta-glucan improved stool consistency on days 3 and 5 (PI) after infection and reduced the frequency of diarrhea throughout the trial compared to other diets.
They said that the number of white blood cells in the low-dose diet was lower than in the control group.
Piglets on both supplementary diets had lower serum haptoglobin on days 2 and 5 post infection and had reduced cortisol on days 5, 8 and 12 post infection.
In addition, the researchers said that pigs on high-dose diets reduced jejunal cell permeability on day 12 post-infection.
The supplement also "upregulated" the expression of Dectin in the jejunal and ileal mucosa, while reducing IL6, compared to the control diet.
"The results of this experiment indicate that in feed supplementation, approximately 108 mg / kg of algae-derived beta-glucan reduced diarrhea in F18 E. coli infected pigs by enhancing intestinal integrity.
"The feeding of algae-derived β-glucan also enhances the host's immune response to E. coli infection.
They added: "The beta-glucan product stimulates T cell activation and reduces inflammation, thus accelerating the recovery of E. coli infected pigs."