The welfare of the neonatal lamb
- 作者：C.M. Dwyer
- 关键词：Sheep ; Lamb ; Lambing ; Welfare ; Behaviour ; Neonate ; Hypothermia ; Starvation ; Neonatal death ; Neonatal mortality
- 刊名：Small Ruminant Research
- 出版年：2008
- 期刊代码：94_09214488
- 类别：abs
- 出版时间：April 2008
- 卷：76
- 期：1-2
- 页码：31-41
- 文件大小：259 K
摘要
The neonatal period is the most vulnerable time in the life of a lamb, with almost half of all pre-weaning mortalities occurring on the day of birth. The welfare challenges faced by the neonate include hunger, hypothermia, pain and injury resulting from the birth process and management interactions, as well as sickness from infectious diseases and distress from maternal separation. A difficult lambing can result in death of a lamb, which may occur without significant suffering on the part of the lamb if pulmonary respiration has not been established, but it can also lead to delivery of an injured lamb. Such animals, in addition to suffering pain as a result of the trauma, are generally less vigorous, slower to suck and may establish a weak relationship with their mother. The main risk factor for both increased lamb mortality and increased difficulty in coping with welfare challenges is low lamb birth weight. Lighter lambs are less vigorous at birth, take longer to suck successfully, thereby increasing their risk of infection, and have a reduced ability to maintain body temperature compared to heavier lambs. These lambs may also have increased stress reactivity throughout life. The appropriate management of the ewe during pregnancy and provision of an optimal birth environment can help minimise the welfare challenges experienced by the lamb, which stem from poor neonatal adaptation to postnatal life and a poor maternal relationship. Breeding for ease of delivery, appropriate behavioural characteristics and cold resistance in the lamb may also be long-term solutions to reduce lamb welfare issues. However, management actions can also be a source of poor welfare in the neonatal lamb, particularly carrying out painful procedures without the use of analgesics, and disruption of the ewe–lamb bond by permanent or temporary separation. Whilst some of these challenges may be unavoidable, consideration of the costs to the lamb of the procedure, and that lambs are better able to cope with welfare challenges when these occur with the presence of their mothers, may help to relieve some aspects of poor welfare in the young lamb.