Individual piglets' contribution to the development of tail biting

Area of Science:

• Animal Behavior
• Veterinary Science
• Animal Welfare

Background:

• Tail-biting outbreaks in pigs are a significant welfare concern.
• Existing hypotheses on individual piglet contributions to tail-biting are not well-quantified.
• Limited quantitative data exists to support or refute individual piglet roles in outbreak development.

Purpose of the Study:

• To quantitatively assess tail-biting behavior development at both pen and individual piglet levels.
• To identify pronounced biters and bitten piglets before and after visible tail damage occurs.
• To test if aggressive piglets (biters) exhibit preferences for specific penmates.

Main Methods:

• Video recordings from 14 pens experiencing tail-biting outbreaks were analyzed.
• Tail-biting incidents (TBIs) were observed and recorded for individually marked piglets.
• Analysis focused on the 6 days before (D-6) and 6 days after (D6) the first visible tail damage (D0).

Main Results:

• Tail-biting intensity increased exponentially from D-6 to D6 (0.7 to 2.3 bites/h).
• Before visible damage (pre-D0), 82% of piglets bit and 96% were bitten; post-D0, figures rose to 99% and 100%.
• Pronounced biters were identifiable early, showing higher biting rates and greater increases in behavior, without preference for specific penmates.

Conclusions:

• Individual piglet behavior can predict tail-biting outbreaks before visible signs.
• Pronounced biters are identifiable 6 days prior to the first observed tail damage.
• Tail-biting is not directed at specific penmates, suggesting environmental or social factors play a role.