This thesis gives a complete description of the changes in the ewe-lamb relationship from birth to weaning, and determines those ewe behaviours of greatest importance to lamb survival and growth. Detailed observations on the grooming behaviour of 50 Scottish Blackface ewes illustrated the extent to which grooming behaviour in twin bearing ewes is affected by the birth of the second lamb. Althugh previous experience does not affect grooming behaviour specifically it does affect the ability of primiparous ewes to cope initially with grooming twin lambs. Previous experience does however, strongly affect ewes responses to active lambs, shown in uncooperative movement by primiparous ewes as lambs attempt to suckle. It was also found, using crossbreeding, that although a lamb, such as the Mule, may have a high birthweight and also stand quickly after birth this does not necessarily mean it will also suckle quickly and effectively. The Mule lambs which were intended to be inactive relative to pure Blackface lambs, were not in the event inactive but failed to show appropriate udder-seeking behaviour. It would appear that the initiation of grooming is genetically controlled and that lamb behaviour, particularly lamb activity may influence the further development of grooming. Longer term observations of 73 Scottish Blackface ewes and lambs outdoors in two years showed that the major changes in the ewe-lamb relationship occur at 3 weeks of age. This corresponds to the time of commencement of weaning, or a new phase in the ewe-lamb relationship and is determined by the willingness of the ewe to allow suckling and the subsequent ability of the lamb to adjust its behaviour. The lamb has to learn that it will only be allowed to suckle when the ewe communicates her wilingness by a headup or call signal. These results are discussed in relation to current literature on parent-offspring conflict and weaning theories. Ewe behavioural measures were also shown to influence lamb growth. Estimations of the quality of the ewe-lamb relationship, using measurements such as headup and call frequencies, appear most likely to have an influence on lamb survival and growth. The influence of ewe behaviour, on the lamb and the ewe-lamb relationship, may well be best investigated in the future through the use of an individual ewe 'character' description.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:660137 |
| Date | January 1991 |
| Creators | O'Connor, Cheryl E. |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/15550 |
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