Mushroom and pig farming: growing "selenium" champignons to replace antibiotics

Mushroom Powder Instead of Zinc Oxide Scientists Find Health Benefits for Weaned Piglets

A group of scientists from the School of Agriculture and Food Sciences and the School of Veterinary Medicine at University College Dublin, Ireland, have proposed optimizing mushroom cultivation for use in pig production. In an article published in the journal Animals 2022 on the MDPI portal, the authors provide a rationale for their idea.

“The forthcoming ban on the use of zinc oxide in pig diets in the European Union is a major challenge facing the swine industry.

In intensive swine production, weaning is associated with dramatic dietary, environmental and social changes leading to stress, reduced feed intake, and intestinal developmental problems in post-weaning piglets.

Post-weaning gut dysfunction is characterized by the activation of pro-inflammatory cytokines, atrophy of the small intestine architecture, proliferation of pathogenic bacteria, and post-weaning diarrhea.

Therefore, pharmacological levels of zinc oxide (ZnO) were added to the diet of piglets after weaning to promote growth and reduce the reproduction of pathogenic bacteria.

However, due to the long-term accumulation of zinc in soils and its association with antimicrobial resistance, the EU has begun phasing out the use of pharmacological levels of ZnO with a total ban by 2022.

Selenium (Se) is an essential micronutrient that performs various functions in enhancing antioxidant capacity, immunity, growth and meat quality in pigs.

Selenium is differentiated into inorganic or organic sources that are commonly added to animal diets to improve growth performance and meat quality.

However, inorganic selenium supplements may have some disadvantages such as toxicity, negative interactions with other minerals, and poor transfer efficiency to animal products, while organic sources are more bioavailable because organic selenium is readily absorbed in the digestive tract and has more high toxicity threshold compared to inorganic sources.

Organic Se nutritional supplements such as selenium-fortified yeast can potentially help minimize post-weaning adverse effects. They have been shown to increase antioxidant capacity, improve immune function and suppress the inflammatory response in weaned piglets (0.25 ppm Se), and increase serum immunoglobulin levels in fattening pigs (0.25 ppm Se).

According to the National Research Council of Ireland, 0.2-0.3 mg/kg (million) of added selenium should meet the requirements for weaned piglets, with the maximum amount of added selenium allowed in the diet of pigs is 0.5 mg/kg of feed .

However, assuming that in the absence of zinc oxide, a level of selenium exceeding the indicated doses would be needed, the idea was proposed for the production of an organic mushroom powder.

Mushrooms are an excellent natural source of bioactive metabolites such as phenolic compounds and polysaccharides, including β-glucans.

Beta-glucans exhibit biological activities such as anti-inflammatory, antioxidant, and immunomodulatory effects. Present in mushrooms, they can act as prebiotics, positively affecting the gut microbiota by increasing the number of lactobacilli and bifidobacteria.

It is known that when irrigated with inorganic sodium selenite, Agaricus bisporus mushrooms (popular double-spored champignon) are enriched with organic selenium, namely selenocystin.

The antioxidant potential of fungi, due to their ability to trap free radicals, along with the antioxidant role of selenium, looks promising for improving the immunomodulatory status in weaned piglets.

Thus, Agaricus bisporus mushrooms offer a unique opportunity to naturally incorporate both β-glucans and organic selenium into the diet of pigs.

Therefore, the aim of this study was to determine the effect of selenium enriched mushroom powder on the diet of piglets after weaning.

ZnO (Cargill, Naas, Ireland) was included at 3100 mg ZnO/kg feed and the diet contained 80% zinc resulting in an inclusion level of 2500 mg Zn/kg feed.

Mushroom powders were obtained from Monaghan Mushroom (Tyholland, Co., Monaghan, Ireland) and were added at 6.5 g/kg to achieve a β-glucan content of 650 mg/kg.

When growing champignons, they were irrigated with sodium selenite to obtain organic Se with a concentration of 45.8 mg/kg of mushroom powder in the form of selenocysteine. Diets were formulated to contain similar levels of net energy (10.6 MJ/kg) and standardized ileal lysine.

One hundred and twenty piglets (Meatline progeny × Large White × Landrace sows) with an average weaning weight of 6.7 kg (SD 0.84 kg) were obtained from a commercial pig farm at weaning (age 28 days) and kept in pens in groups of three. .

Weaned piglets were separated by body weight, sex and litter of origin and randomly distributed into experimental groups with different diets and doses of selenium and a group with zinc oxide as a control.

Our study showed that 0.3 ppm selenium supplementation—using a selenium-enriched mushroom powder—resulted in a positive effect on faecal performance and had similar growth performance in piglets compared to the zinc oxide group during the first 21 days post-weaning.

A selenium incorporation level of 0.6 ppm using selenium-enriched mushroom powder and selenite improved animal performance and many aspects of gastrointestinal health at 21 and 39 days post-weaning.”