What are Phytogenic Feed Additives? Are Choline Chloride and Vitamins Part of it?

1. What Are Phytogenic Feed Additives?

Definition
Phytogenic feed additives (PFAs), also called phytobiotics or botanicals, are natural bioactive compounds derived from plants—such as herbs, spices, extracts, and essential oils—used in animal nutrition to improve feed efficiency, animal performance, and product quality (Hashemi & Davoodi, 2011; Gruber et al., 2025).

Main Constituents include:

Secondary plant metabolites: alkaloids, flavonoids, saponins, tannins, phenolic compounds.
Essential oils: thymol, carvacrol, cinnamaldehyde.
Other derivatives: glycosides, terpenoids, steroids.

Forms of PFAs:

Whole plants or plant parts (roots, leaves, seeds, fruits).
Extracts and essential oils in liquid or powder form.

2. Do Choline Chloride and Vitamins Belong to PFAs?

Compound	Category	Source Characteristics	Why Not PFAs
Choline chloride	Nutritional additive (vitamin-like)	Often synthetically produced; also present in plants	Classified as a vitamin-like nutrient, not as a plant bioactive compound
Vitamins (A, D, E, K, B-complex, etc.)	Nutritional additives (vitamins)	Occur in plants and animals; supplied mainly as synthetic forms in feed	Their role is nutrient supplementation, not plant-derived functional activity

👉 Although choline and vitamins can be extracted from plants, they are classified as nutritional additives, focusing on providing essential nutrients. PFAs, on the other hand, emphasize functional properties (antimicrobial, antioxidant, gut health), not just nutrition.

3. Main Categories of Feed Additives

According to EU Regulation EC 1831/2003 and major scientific reviews, feed additives fall into these categories:

Nutritional additives: vitamins, amino acids, minerals, choline, fatty acids.
Technological additives: preservatives, antioxidants, enzymes, emulsifiers, anti-caking agents, carriers.
Sensory additives: flavors, sweeteners, colorants, pigments.
Zootechnical additives: probiotics, prebiotics, yeast products, organic acids, phytogenic additives.

4. Characteristics of Phytogenic Feed Additives

Natural origin and safety: generally safe with low residue concerns.
Multiple bioactive functions: antibacterial, antioxidant, anti-inflammatory, immunomodulatory.
Diverse forms: whole herbs, powders, essential oils, standardized plant extracts.
Variability: composition influenced by plant species, harvest season, and processing, which may cause inconsistent efficacy.

5. Functional Roles of PFAs

PFAs provide a wide range of benefits:

Growth promotion: improve feed conversion ratio (FCR) and weight gain.
Gut health: support beneficial microbiota, inhibit pathogens, and enhance intestinal structure.
Antioxidant and anti-stress effects: reduce oxidative damage and stress-related losses.
Antibiotic alternative: act as natural replacements for antibiotic growth promoters (AGPs).
Environmental benefits: in ruminants, regulate rumen fermentation and reduce methane emissions.

6. Proportion and Functions of Feed Additives in Animal Diets

(a) Approximate proportions of different additive categories in feed formulas

Additive Category	Typical Use in Feeds	Inclusion (within premix)	Main Functions
Nutritional (Vitamins, AA, Minerals, Choline)	All livestock and aquaculture	5–15%	Essential nutrient supply
Technological additives	All species	<5%	Shelf-life extension, digestion support
Sensory additives	Poultry, swine (eggs, meat, fish)	<1%	Improve palatability, color, flavor
Zootechnical additives (Probiotics, PFAs, enzymes)	Poultry, swine, ruminants, fish	1–5%	Gut health, performance enhancement

* Percentages indicate share within the additive premix portion of feed, not total feed mass.

(b) Species-specific emphasis

Poultry (broilers and layers): PFAs, probiotics, and enzymes for gut health and growth; pigments for egg yolk and skin coloration.
Swine (especially piglets): nutritional additives (amino acids, vitamins) for growth; PFAs, prebiotics, and acidifiers to improve gut health and reduce antibiotic use.
Ruminants (cattle, sheep, goats): PFAs to modulate rumen fermentation, improve feed efficiency, and reduce methane emissions.
Aquaculture: PFAs for immune modulation, growth promotion, and palatability; vitamins and minerals to meet essential requirements.

7. Feed Additives Classification

Main Category	Sub-category	Examples	Description
Nutritional Additives	Vitamins	Vit A, D, E, K, B1, B2, B6, B12, Niacin, Biotin, Folic acid, Choline chloride	Supply essential vitamins and vitamin-like substances for growth and metabolism
	Amino Acids	Lysine, Methionine, Threonine, Tryptophan	Provide essential amino acids, improve protein synthesis
	Minerals	Ca, P, Na, Cl, Mg, Fe, Cu, Zn, Se	Supply macro- and micro-minerals
Technological Additives	Preservatives	Propionic acid, Formic acid	Extend feed shelf life
	Antioxidants	Ethoxyquin, BHA, BHT, Vit E	Prevent oxidative rancidity of fats
	Enzymes	Phytase, Xylanase, Amylase	Improve nutrient digestibility
	Emulsifiers	Lecithin	Enhance fat digestion and absorption
	Anti-caking / Carriers	Silica, Clay	Maintain free-flowing properties of feed
Sensory Additives	Pigments	Lutein, Capsanthin, Canthaxanthin	Improve pigmentation of egg yolk, skin, meat
	Flavourings	Vanillin, Anethole	Enhance feed palatability
Zootechnical Additives	Probiotics	Lactobacillus, Bacillus	Support healthy gut microbiota
	Prebiotics	MOS, FOS, Inulin	Stimulate growth of beneficial bacteria
	Yeast Products	Yeast culture, β-glucan, MOS	Enhance immunity and performance
	Digestive Enzymes	Protease, Lipase	Improve digestion and nutrient utilization
	Acidifiers	Citric acid, Lactic acid	Lower gut pH, inhibit pathogens
Phytogenic Feed Additives (PFAs)	Essential Oils	Thymol, Carvacrol, Cinnamaldehyde	Antimicrobial, anti-inflammatory, gut health
	Herbs & Spices	Oregano, Garlic, Ginger, Rosemary	Improve palatability, stimulate digestion
	Plant Extracts	Flavonoids, Polyphenols, Saponins, Tannins	Antioxidant, anti-stress, immunomodulation
	Resins & Bitters	Quinine, Alkaloids	Stimulate digestive secretions

7. References

Hashemi, S. R., & Davoodi, H. (2011). Phytogenic feed additives: A review. Journal of Animal and Veterinary Advances, 10(25), 3514–3523. Retrieved from https://pmc.ncbi.nlm.nih.gov/articles/PMC11127233/
Gruber, C., Ocelova, V., Kesselring, J. C., & Wein, S. (2025). Phytogenic feed additives as a sustainable alternative to antibiotics: Enhancing growth and disease resistance in Nile tilapia (Oreochromis niloticus). Animals, 15(3), 380. https://doi.org/10.3390/ani15030380
Windisch, W., et al. (2008). Plant-derived feed additives—Known as phytogenics—comprising herbs, spices, essential oils, and plant extracts. World’s Poultry Science Journal, 64(3), 278–285.
Frontiers in Veterinary Science (2021). The use of phytogenic feed additives to enhance performance and health. Retrieved from https://www.frontiersin.org/articles/10.3389/fvets.2021.685262/full
Wikipedia contributors. (2025). Phytogenics. Wikipedia. Retrieved from https://en.wikipedia.org/wiki/Phytogenics