View Item 
        •   Utrecht University Student Theses Repository Home
        • UU Theses Repository
        • Theses
        • View Item
        •   Utrecht University Student Theses Repository Home
        • UU Theses Repository
        • Theses
        • View Item
        JavaScript is disabled for your browser. Some features of this site may not work without it.

        Browse

        All of UU Student Theses RepositoryBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

        Effect of birth order on performance and affective state of pigs

        Thumbnail
        View/Open
        Thesis Effect of birth order on performance and affective state of pigs.pdf (1.279Mb)
        Publication date
        2018
        Author
        Slegers, Y.
        Metadata
        Show full item record
        Summary
        In pigs, birth order is associated with higher pre-weaning mortality. However, knowledge on the effect of birth order on welfare of surviving piglets is limited. The aim of this study was to investigate the possible link between birth order and both piglet performance and affective state. Firstly, the following data was collected from 393 piglets: stillbirth rate, intactness of the umbilical cord, cyanosis, drinking time, birth weight, teat order, weaning and end weight. Secondly, an active-choice judgement bias test was performed with low birth order (n=10) and high birth order (n=10) piglets. During the preceding discrimination training, the pigs learned to associate two tone cues with either a high or low reward, provided at different locations. After training, ambiguous intermediate tones were introduced and the pig’s choice of location was observed. Results showed that last-born piglets had a higher birth weight than middle-born piglets. They also drank from more caudal teats than first-born piglets. In the judgement bias test, low and high birth order piglets showed a similar learning rate, latency and optimistic bias. Before the first individual trial, salivary cortisol levels were highest in low birth order pigs. However, after the trial, levels had decreased to the high birth order pigs’ level. Additional behavioral tests and further study of stress response are proposed for validation of these results.
        URI
        https://studenttheses.uu.nl/handle/20.500.12932/31560
        Collections
        • Theses
        Utrecht university logo