title: Early neonatal lamb mortality: postmortem findings.
abstract: An investigation of stillbirth and early neonatal lamb mortality was conducted in sheep flocks in Norway. Knowledge of actual causes of death are important to aid the interpretation of results obtained during studies assessing the risk factors for lamb mortality, and when tailoring preventive measures at the flock, ewe and individual lamb level. This paper reports on the postmortem findings in 270 liveborn lambs that died during the first 5 days after birth. The lambs were from 17 flocks in six counties. A total of 27% died within 3 h after birth, 41% within 24 h and 80% within 2 days. Most lambs (62%) were from triplet or higher order litters. In 81% of twin and larger litters, only one lamb died. The most frequently identified cause of neonatal death was infectious disease (n=97, 36%); 48% (n=47) of these died from septicaemia, 25% (n=24) from pneumonia, 22% (n=21) from gastrointestinal infections and 5% (n=5) from other infections. Escherichia coli accounted for 65% of the septicaemic cases, and were the most common causal agent obtained from all cases of infection (41%). In total, 14% of neonatal deaths resulted from infection by this bacterium. Traumatic lesions were the primary cause of death in 20% (n=53) of the lambs. A total of 46% of these died within 3 h after birth and 66% within 24 h. Severe congenital malformations were found in 10% (n=27) of the lambs, whereas starvation with no concurrent lesions was the cause of death in 6% (n=17). In 16% (n=43) of the lambs, no specific cause of death was identified, lambs from triplet and higher order litters being overrepresented among these cases. In this study, the main causes of neonatal lamb mortality were infection and traumatic lesions. Most neonatal deaths occurred shortly after birth, suggesting that events related to lambing and the immediate post-lambing period are critical for lamb survival.
authors.affiliation: 1Department of Production Animal Clinical Sciences, Faculty of Veterinary Medicine and Biosciences,Norwegian University of Life Sciences,P.O. Box 8146 Dep. N-0033 Oslo,Norway.
authors.forename: I H
authors.initials: IH
authors.lastname: Holmøy
authors.affiliation: 1Department of Production Animal Clinical Sciences, Faculty of Veterinary Medicine and Biosciences,Norwegian University of Life Sciences,P.O. Box 8146 Dep. N-0033 Oslo,Norway.
authors.forename: S
authors.initials: S
authors.lastname: Waage
authors.affiliation: 1Department of Production Animal Clinical Sciences, Faculty of Veterinary Medicine and Biosciences,Norwegian University of Life Sciences,P.O. Box 8146 Dep. N-0033 Oslo,Norway.
authors.forename: E G
authors.initials: EG
authors.lastname: Granquist
authors.affiliation: 2Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine and Biosciences,Norwegian University of Life Sciences,P.O. Box 8146 Dep. N-0033 Oslo,Norway.
authors.forename: T M
authors.initials: TM
authors.lastname: L'Abée-Lund
authors.affiliation: 1Department of Production Animal Clinical Sciences, Faculty of Veterinary Medicine and Biosciences,Norwegian University of Life Sciences,P.O. Box 8146 Dep. N-0033 Oslo,Norway.
authors.forename: C
authors.initials: C
authors.lastname: Ersdal
authors.affiliation: 3Animalia Norwegian Meat and Poultry Research Centre,P.O. Box 396 Økern,N-0513 Oslo,Norway.
authors.forename: L
authors.initials: L
authors.lastname: Hektoen
authors.affiliation: 4Department of Basic Sciences and Aquatic Medicine, Faculty of Veterinary Medicine and Biosciences,Norwegian University of Life Sciences,P.O. Box 8146 Dep. N-0033 Oslo,Norway.
authors.forename: R
authors.initials: R
authors.lastname: Sørby
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000013:Congenital Abnormalities / Q000473:pathology / Q000662:veterinary; D005260:Female; D009664:Norway; D011247:Pregnancy; D012307:Risk Factors; D012756:Sheep; D012757:Sheep Diseases / Q000401:mortality / Q000473:pathology*; D013217:Starvation / Q000662:veterinary; D050497:Stillbirth / Q000662:veterinary
keywords: 
                 postmortem
              ; lamb mortality; neonatal; sheep