This thesis compares growth and behaviour of domestic sows and piglets in confined pens versus get-away pens (where sows could leave their fitters at will), to ask whether parent-offspring conflict occurs, whether it increases with offspring age, whether it involves offspring access to the udder, and whether it affects animal production or welfare. Parent-offspring conflict occurs in domestic pigs: piglets of Confined sows suckled more and ate less solid food but grew at the same rate as piglets from Get-away sows, indicating they obtained more milk. Confined sows lost more weight than Get-away sows and returned to oestrus later, indicating a fitness cost of providing the additional milk. Parent-offspring conflict increased with piglet age: as the fitter aged, Get-away sows spent more time away from their young and the differences between Get-away sows and Confined sows in weight loss and nursing frequency increased. In Get-away sows, the reduction in contact with their young occurred rapidly, but its timing varied greatly among individual sows. Behavioural conflict over access to the udder is a plausible mechanism by which conflict is expressed in swine: piglets from Confined pens spent more time nuzzling the udder than piglets of Get-away sows. Piglets from Get-away sows nuzzled the udder a higher proportion of the time when the sow was present than piglets from Confined sows. Get-away sows terminated more nursings than Confined sows thus limiting the amount of contact piglets had with the udder after nursing. Mowing sows to control maternal provisioning improved productivity: there was a slight benefit of reduced time to the next oestrus for Get-away sows. Piglets from Get-away sows gained more weight and consumed more food after weaning than piglets from Confined sows. There was only slight evidence that get-away pens reduced behavioural indicators of post-weaning stress (e.g., movements, vocalizations, response to playback of vocalizations) for either the pi
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.35041 |
| Date | January 1998 |
| Creators | Pajor, Edmond A. |
| Contributors | Kramer, Donald L. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Biology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001641387, proquestno: NQ44546, Theses scanned by UMI/ProQuest. |
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