Table 3.
Ethogram with aggressive patterns recorded in the current study.
| Aggressive Patterns | |||
|---|---|---|---|
| Category | Behavioural Pattern | Type | Description |
| Offensive | Aggressive bite | C | A piglet opens its mouth and closes its teeth tight on a small piece of the opponent’s flesh (except tail) |
| Aggressive head knocking | C | A piglet lunges or jerks its head with physical contact and mouth closed | |
| Aggressive kick | C | A piglet kicks with one or both hind limbs the opponent, striking it | |
| Aggressive lifting | C | A piglet attempts to displace the opponent by lifting or levering it with snout or head | |
| Aggressive mount/climb | C | A piglet forces the opponent to move away by rising upon the rear of the partner | |
| Aggressive push | C | A piglet presses its head, neck, shoulder or body against the opponent in an aggressive context | |
| Attempt aggressive bite | C | A piglet opens its mouth, directs or turns its head towards the body of the opponent and closes its mouth without contact | |
| Neutral | Head tilting | LA | A piglet moves the head to the side when the opponent passes or gets closer |
| Threat | LA | A piglet arches the back to the opponent or makes a forward movement of the head and stares at the opponent with no physical contact | |
| Rest during fight | LA | A piglet rests and does not exhibit aggressive behavior while being hit-during a reciprocal real fight session for at least 3 s. (reciprocal fighting must occur before and after this event for it to be classified as a rest during fight). | |
| Defensive | Asymmetric parallel | C | The piglets involved in a real fight face the same direction, standing side by side and one of them is slightly ahead of the other. A piglet—the one placed slightly in front of the other—moves forward, pushing the opponent away with his shoulder and moving his head away from the opponent to avoid having its ears bitten. |
| Avoidance | LA | A piglet moves away with a depressed tail when the opponent approaches | |
| Flee | LA | A piglet runs away from the opponent. The opponent can react with a chase. | |
| Withdrawal | LA | A piglet tries to leave a reciprocal real fight session, the opponent continues to bite the recipient with a rate greater than one bite for 3 s, and the recipient reacts with any harmful aggression for more than 3 s. After that, the piglets involved do not have interactions for at least 3 s. | |