FASH2: Perinatal Lamb Mortality Flashcards
What is the lambing percentage?
The number of lambs born and surviving until a definite event such as marking or weaning per 100 ewes mated
What event determines the lambing percentage?
The mating period
- Oestrus behaviour
- Ovulation rate
- Fertilisation
- Conception
Late Pregnancy
- Foetal development
- Foetal survival/abortion
- Ewe deaths
Lambing
- Perinatal Lamb Mortality
- Lamb losses from 1 week old to weaning
What age group is considered perinatal?
First week of birth
What are the reasons for perinatal lamb mortality?
Under-nutrition of the pregnant ewe
Dystocia
Under-nutrition of the newborn lamb
What do lambs need to ensure survival?
To ensure survival, lambs must be born mature, with adequate energy reserves, free from birth stress, and receive adequate postpartum nutrition
What impacts pre-partum nutrition for the foetus?
Severe maternal undernutrition during mid-pregnancy causes poor placental development. This leads to poor oxygen, nutrient, and electrolyte transfer > low lamb birth weights, long-term foetal hypoxaemia inhibits the newborn lamb’s capacity for thermoregulation.
Maternal undernutrition during the final six weeks of pregnancy results in the birth of hypoglycaemic lambs and in poor udder development and colostrum production
What are the maternal factors responsible for lamb starvation?
- Genotype (poor mothering behaviour)
- Inexperience
- Undernutrition
- Dystocia
- Concurrent diseases
- Mastitis
- Multiple Births
What are the lamb factors responsible for lamb starvation?
- Genotype (some terminal sire bred lambs are slower to suckle)
- Multiple litters
- Birth stress
- Prenatal malnutrition
- Hypothermia (don’t suckle)
- Infectious disease
What extrinsic factors are responsible for lamb starvation?
- High stocking density of lambing ewes (resulting in mis-mothering)
- Disturbance of lambing or newly-lambed ewes
- Human interference
- Absence of feed near to lambing site
- Exposure
Describe a PM of a newborn lamb.
- Weight lamb
- Examine feet to determine if the lamb walked
- Examine the umbilical cord for signs of blood clotting and desiccation
- Check the carcase for signs of meconium staining, trauma, swellings and other physical abnormality
- Examine the brown fat around the kidneys and pericardium for signs fo atrophy
- Open the abomasum to determine the presence of clotted milk
- Check for rupture of liver capsule
- Examine the lungs to determine if they are inflated
- Check for subQ oedema
- Examine the thyroid glands for evidence of enlargement
- Examine the carcase for other evidence of sepsis or inflammation
What disease is associated with average body weights, atrophied brown fat, an absence of clotted milk in the abomasum?
Hypothermia
What disease is associated with heavy bodyweights, submandibular oedema, and/or rupture of the liver capsule?
Dystocia
What management practices minimise perinatal mortality?
- Ensure adequate maternal nutrition
- Avoid dystocia
- Ensure adequate early lamb nutrition
Which diseases are a consequence of poor colostrum intake during the first few hours of life and poor hygiene of the lambing environment?
Navel ill, joint ill, watery mouth
