So, to fulfill the repertoire of behaviours related to foraging and other investigation and manipulation activities, enrichment objects should be edible, chewable, rootable and destructible.
The following is a list of some typical materials offered as enrichment and the behaviours that they can fulfill.
The first list includes examples of enrichment objects, or toys.
| Materials offered as enrichment: objects or toys | Properties that promote proper manipulation behaviour | ||||
|---|---|---|---|---|---|
  |
Chain |
Edible
|
Chewable
Only superficial chewing possible |
Rootable
|
Destructible
|
   |
Plastic/ Rubber |
Edible
|
Chewable
The harder the plastic, the less chewable it is |
Rootable
|
Destructible
The harder the plastic, the less destructible it is |
  |
Wooden block |
Edible
|
Chewable
Hard wood, can be too hard for the pigs to chew |
Rootable
|
Destructible
Wood can splinter. Hard wood, in big blocks, can be too hard for the pigs to destruct |
  |
Cardboard |
Edible
BUT
if recycled cardboards contain toxins
|
Chewable
|
Rootable
Some rooting possible if left at floor level |
Destructible
|
 |
Ball |
Edible
|
Chewable
|
Rootable
|
Destructible
|
  |
Cloth: Hessian sack and rope |
Edible
|
Chewable
|
Rootable
Some rooting possible if sacking left at floor level |
Destructible
|
 |
Salt lick |
Edible
|
Chewable
|
Rootable
|
Destructible
|
The second list includes examples of enrichment offered as bedding or in a rack.
| Materials offered as enrichment: substrate or roughage | Properties that promote proper manipulation behaviour | ||||
|---|---|---|---|---|---|
 |
Straw |
Edible
|
Chewable
|
Rootable
|
Destructible
|
 |
Hay |
Edible
|
Chewable
|
Rootable
|
Destructible
|
 |
Silage |
Edible
|
Chewable
|
Rootable
|
Destructible
|
 |
Soil |
Edible
Soil may contain edible components such as plant roots |
Chewable
|
Rootable
|
Destructible
|
 |
Wood shavings |
Edible
|
Chewable
|
Rootable
|
Destructible
|
 |
Sawdust |
Edible
|
Chewable
|
Rootable
|
Destructible
|
 |
Rack feed with, for example, straw, hay or silage. |
Edible
|
Chewable
|
Rootable
|
Destructible
|
“pigs must have permanent access to a sufficient quantity of material to enable proper investigation and manipulation activities, such as straw, hay, wood, sawdust, mushroom compost, peat or a mixture of such, which does not compromise the health of the animals.” (EU Directive 2008/120/EC, Annex 1, para 4)