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Judgment Bias During Gestation in Domestic Pigs
Emily V Bushby1,2, Sheena C Cotter1, Anna Wilkinson1
1School of Life Sciences, University of Lincoln, Lincoln, United Kingdom.
Frontiers in Veterinary Science
|June 1, 2022
Summary
Pregnancy alters mood in pigs, affecting their judgment bias negatively as gestation progresses. This highlights new welfare concerns for pregnant, captive animals.
Area of Science:
- Animal behavior
- Comparative psychology
- Animal welfare science
Background:
- Pregnancy is known to affect mood in humans and rats.
- The impact of gestation on mood in other mammals remains understudied.
- Understanding affective states in pregnant animals is crucial for welfare.
Purpose of the Study:
- To assess changes in pigs' judgment bias as a measure of affective state during gestation.
- To investigate how pregnancy influences emotional states in domestic pigs.
- To explore potential welfare implications for pregnant, captive species.
Main Methods:
- Pigs were trained on a spatial judgment bias task.
- Testing occurred before mating, and during early and late gestation.
- Responses to ambiguous locations were analyzed to infer affective state.
Main Results:
- Pigs showed increasingly negative judgment bias as gestation advanced.
- Consistent individual differences in baseline optimism were observed.
- Affective state changes during gestation are suggested, though learning effects cannot be excluded.
Conclusions:
- Gestation appears to alter judgment bias and affective state in domestic pigs.
- These findings raise novel welfare considerations for pregnant, multiparous species.
- Further research with control groups is needed to confirm gestation-specific effects.
