Table 1.

Definitions related to feed characteristics commonly associated to the nutraceutical concept.

Concept	Definition	Comment	Reference
Feed additive	A compound generally of synthetic origin added to the feed	Dependent of VFI and long-term administration to exert their effects	[35,86,89]
Cosmeceutical	A cosmetic product with active ingredients	Independent of VFI. Medium to long-term administration to exert their effects	[78,88]
Functional food	A food containing nutrients and ingredient(s) with beneficial effects beyond adequate nutritional properties	Dependent of VFI and need long-term administration to exert their effects. The closest to the nutraceutical definition, however functional food includes fortified foods while nutraceuticals do not	[85,86]
Phytotherapeutic	A compound of natural origin. It can be a plant, or its extracts used instead of “conventional drugs”	Independent of VFI and need short-term administration to exert their effects	[35,85]
Ethnoveterinary or ethnomedicine	Practices derived from ancient knowledge, beliefs and skills to prevent and treat animal diseases	Dependent of VFI and need long-term administration to exert their effects	[90,91]

VFI: Voluntary feed intake.