Polyphenol-Enriched Diets in Animal Nutrition

Polyphenols are a diverse class of plant secondary metabolites that exert potent antioxidant and anti-inflammatory effects when incorporated into animal feed. Interest in polyphenol-enriched diets has grown in response to consumer demand for chemical-free animal products, tighter regulations on antibiotic use and a drive towards sustainable agriculture. In livestock and poultry systems, polyphenols sourced from grape pomace, olive pomace, tea extracts and other fruit and vegetable by-products have been shown to modulate gut microbiota, enhance immune resilience and reduce oxidative damage in tissues. Such bioactive compounds can also influence nutrient digestibility, lean meat yield and the fatty acid profile of animal-derived foods, thereby improving shelf-life and nutritional value. By valorising agro-industrial co-products rich in phenolic compounds, producers can adopt cleaner, greener feeding strategies that confer animal welfare benefits, lower environmental impact and deliver value-added products to the market.

Research from Nature Portfolio

A recent study investigated dietary inclusion of olive pomace at graded levels in the feed of growing quails. Diets containing up to 150 g/kg of pomace did not compromise growth rate or feed conversion but higher inclusion reduced overall weight gain and carcass yield. Carcasses from birds on moderate pomace levels exhibited improved meat colour stability and maintained normal serum biochemistry and organ morphology. The work identifies an optimal inclusion threshold that balances the nutritive value of fibre and bioactive phenolics with the risk of performance decline, highlighting olive by-products as viable functional ingredients in game and poultry nutrition.

Polyphenol-Enriched Diets in Animal Nutrition publication trend

The graph below shows the total number of articles in polyphenol-enriched diets in animal nutrition across all publications each year (not limited to Nature Index journals).

Technical terms

Polyphenols: Plant-derived compounds with multiple phenol units that act as antioxidants and modulate inflammatory pathways.

Bioavailability: The proportion of a nutrient or bioactive compound that is absorbed and utilised in physiological processes.

Oxidative stress: A state in which excess reactive oxygen species overwhelm endogenous antioxidant defences, leading to cellular damage.

Procyanidins: A subgroup of polyphenols formed by oligomerisation of flavan-3-ol units, notable for their free-radical scavenging capacity.

Lipid peroxidation: Oxidative degradation of lipids that compromises cell membranes and accelerates spoilage in animal products.

References

1. Antioxidant Activity, Metabolism, and Bioavailability of Polyphenols in the Diet of Animals. Antioxidants (2023).
2. Fruit and Vegetable Co-Products as Functional Feed Ingredients in Farm Animal Nutrition for Improved Product Quality. Agriculture (2015).
3. Effect of dietary olive (Olea europea) pomace on productive performance, and physiological and meat quality parameters in Jumbo quail. Scientific Reports (2023).
4. Enriching Eggs with Bioactive Compounds through the Inclusion of Grape Pomace in Laying Hens Diet: Effect on Internal and External Egg Quality Parameters. Foods (2024).
5. Impact of a sustained consumption of grape extract on digestion, gut microbial metabolism and intestinal barrier in broiler chickens. Food & Function (2019).