At the June round of BWBL meetings held at Nhill and Birchip, Drs Andrew Kennedy of DEDJTR and Andrew Whale of Livestock Logic, discussed how management influences reproduction, from conception and throughout pregnancy, and onto lamb survival at birth through to weaning.
Dr Whale’s skilled autopsy of local lambs showed how to determine the cause of death. He highlighted how paddock conditions linked to lamb physiology and ability to initially bond with the ewe and suckle, and subsequent ability to survive.
Examples of the symptoms examined were:
- Body weight: ideally bodyweight of a Merino lamb should be 4.0–5.5 kg, and 4.5-6.0 kg for a crossbred lamb.
- External signs of predation: evident by bite marks or tail missing. Majority of predation is secondary; the lamb was already weak or dead.
- Meconium on body: born dead. Ewe hasn’t cleaned it.
- Feet: These should be firm and clean. If there is still a film over the hoof, the lamb never walked.
- Lungs: want them pink and inflated. If they’re dark the lamb hasn’t taken a breath, i.e. was born dead.
- Liver: should be uniform in colour. If it’s been dead for a while the liver will go darker on the side it is lying on.
- Kidneys: usually has white fat. If fat is reddish-purple, the lamb hasn’t had enough energy from the ewe, and has had to draw from its own fat.
- Stomach: if it contains clotted milk the lamb has drunk. If not it the lamb has failed to suckle. There may be meconium, indicating the lamb got stuck during labour.
- Brain: Dystocia will cause bleeding around the brain, and there may be oedema (clear fluid) under the skin.
A booklet is currently being produced which details how to conduct an autopsy and has photographs of the different symptoms to establish the history of the lamb and why it may have died. BCG will obtain copies of these when they become available.