Neonatal lamb mortality: factors associated with the death of Australian lambs
G. Refshauge A B F , F. D. Brien A C , G. N. Hinch A E and R. van de Ven D
+ Author Affiliations
- Author Affiliations
A Sheep CRC, University of New England, Armidale, NSW 2351, Australia.
B NSW Department of Primary Industries, Cowra, NSW 2794, Australia.
C School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, SA 5371, Australia.
D NSW Department of Primary Industries, Orange, NSW 2800, Australia.
E School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia.
F Corresponding author. Email: gordon.refshauge@dpi.nsw.gov.au
Animal Production Science 56(4) 726-735 https://doi.org/10.1071/AN15121
Submitted: 3 March 2015 Accepted: 10 September 2015 Published: 21 December 2015
Abstract
The objective of the present study was to examine the factors associated with the death of neonatal lambs. Postmortem autopsy data were collected from 3198 newborn lambs in the Sheep CRCs Information Nucleus Flock situated in various environments throughout southern Australia. The proportion dying by category from highest to lowest was starvation–mismothering (25%), stillbirth (21%), birth injury (18%), dystocia (9%), death in utero–prematurity (10%), predation (7%), cold exposure (5%), undiagnosed (4%), infection (1%) or misadventure (1%). Factors best explaining the probability of lambs falling into a death category included both birth type and birthweight for dystocia, stillbirth, starvation–mismothering and death in utero–prematurity. The probability of a lamb falling into any category was predicted at the mean birthweight, within birth type. Single-born lambs were more likely to die from dystocia and stillbirth, while twin lambs were more likely to die from birth injury, starvation–mismothering or from undiagnosed causes. Triplet lambs were more likely to die from starvation–mismothering or death in utero–prematurity. Sire type (Merino, maternal or terminal) did not affect the proportions of lambs within any category. The proportions lost to each cause of death were largely consistent among locations, despite the rate of death varying. Dystocia, stillbirth and birth injury, as evidenced by the presence of oedema around the head and neck or by lesions of the central nervous system, accounted for 48% of autopsied lambs. We conclude that for improvements to occur in the rates of lamb survival, the Australian sheep industry must focus on minimising losses due to dystocia, stillbirth, birth injury and starvation.
Additional keywords: autopsy, cause of death, dystocia, neonatal lamb mortality, starvation.
References
Alexander G (1980) Husbandry practices in relation to maternal-offspring behaviour. In ‘Reviews in rural science IV’. (Eds M Wodzicka-Tomaszewska, TN Edey, JJ Lynch) pp. 99–107. (University of New England Press: Armidale, NSW)Alexander G (1984) Constraints to lamb survival. In ‘Reproduction in sheep’. (Eds DR Lindsay, DT Pearce) pp. 199–209. (Australian Academy of Science, in conjunction with the Australian Wool Corporation: Canberra)
Alexander G, Peterson JE (1961) Neonatal mortality in lambs. Australian Veterinary Journal 37, 371–381.
| Neonatal mortality in lambs.Crossref | GoogleScholarGoogle Scholar |
Alexander G, Peterson JE, Watson RH (1959) Neontal mortality in lambs: intensive observations during lambing in a Corriedale flock with a history of high lamb mortality. Australian Veterinary Journal 35, 433–441.
| Neontal mortality in lambs: intensive observations during lambing in a Corriedale flock with a history of high lamb mortality.Crossref | GoogleScholarGoogle Scholar |
Alexander G, Lynch JJ, Mottershead BE, Donnelly JB (1980) Reduction in lamb mortality by means of grass wind-breaks: results of a five-year study. Proceedings of the Australian Society of Animal Production 13, 329–332.
Bates D, Maechler M, Bolker B (2011) lme4: linear mixed-effects models using S4 classes. R package version 0.999375-38. Available at http://CRAN.R-project.org/package=lme4 [Verified 9 November 2015]
Behrendt R, van Burgel AJ, Bailey A, Barber P, Curnow M, Gordon DJ, Edwards JEH, Oldham CM, Thompson AN (2011) On-farm paddock-scale comparisons across southern Australia confirm that increasing the nutrition of Merino ewes improves their production and the lifetime performance of their progeny. Animal Production Science 51, 805–812.
| On-farm paddock-scale comparisons across southern Australia confirm that increasing the nutrition of Merino ewes improves their production and the lifetime performance of their progeny.Crossref | GoogleScholarGoogle Scholar |
Brien FD, Hebart ML, Jaensch KS, Smith DH, Grimson RJ (2009) Genetics of lamb survival: a study of Merino resource flocks in South Australia. In ‘Proceedings of the 18th conference of the Association for the Advancement of Animal Breeding and Genetics’, Barossa Valley, South Australia, 28 September – 1 October. pp. 492–495.
Brien FD, Hebart ML, Smith DH, Hocking Edwards JE, Greeff JC, Hart KW, Refshauge G, Bird-Gardiner TL, Gaunt G, Behrendt R, Robertson MW, Hinch GN, Geenty KG, van Der Werf JHJ (2010) Opportunities for genetic improvement of lamb survival. Animal Production Science 50, 1017–1025.
| Opportunities for genetic improvement of lamb survival.Crossref | GoogleScholarGoogle Scholar |
Brown DJ, Jones RM, Hinch GN (2014) Genetic parameters for lamb autopsy traits. Animal Production Science 54, 736–744.
| Genetic parameters for lamb autopsy traits.Crossref | GoogleScholarGoogle Scholar |
Dalton DC, Knight TW, Johnson DL (1980) Lamb survival in sheep breeds on New Zealand hill country. New Zealand Journal of Agricultural Research 23, 167–173.
| Lamb survival in sheep breeds on New Zealand hill country.Crossref | GoogleScholarGoogle Scholar |
Duff XJ, McCutcheon SN, McDonald MF (1982) Central nervous system injury as a determinant of lamb mortality. Proceedings of the New Zealand Society of Animal Production 42, 15–17.
Dutra F, Banchero G (2011) Polwarth and Texel ewe parturition duration and its association with lamb birth asphyxia. Journal of Animal Science 89, 3069–3078.
Dutra F, Quintans G, Banchero G (2007) Lesions in the central nervous system associated with perinatal lamb mortality. Australian Veterinary Journal 85, 405–413.
| Lesions in the central nervous system associated with perinatal lamb mortality.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2srot1Cisg%3D%3D&md5=3ff068486601d69432a09eea3679a7ceCAS | 17903128PubMed |
Eales FA, Gilmour JS, Barlow RM, Small J (1982) Causes of hypothermia in 89 lambs. The Veterinary Record 110, 118–120.
| Causes of hypothermia in 89 lambs.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaL2c%2FhvFWgug%3D%3D&md5=c7b64f62384ecfcdffa7fba576796c79CAS | 6892265PubMed |
Everett-Hincks JM, Mathias-Davis HC, Greer GJ, Auvray BA, Dodds KG (2014) Genetic parameters for lamb birth weight, survival and death risk traits. Journal of Animal Science 92, 2885–2895.
| Genetic parameters for lamb birth weight, survival and death risk traits.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BC2cjgt1ersg%3D%3D&md5=39f48ce36fee1daf6a13b1ebe01b2ad8CAS | 24802039PubMed |
Fowler DG (2007) Lamb marking performance for ultrasound scanned ewes in Australian sheep flocks. Final report AHW.131. Meat & Livestock Australia, Sydney.
Fowler DG, Wilkins JF (1984) Diagnosis of pregnancy and number of foetuses in sheep by real-time ultrasonic imaging. I. Effects of number of foetuses, stage of gestation, operator and breed of ewe on accuracy of diagnosis. Livestock Production Science 11, 437–450.
| Diagnosis of pregnancy and number of foetuses in sheep by real-time ultrasonic imaging. I. Effects of number of foetuses, stage of gestation, operator and breed of ewe on accuracy of diagnosis.Crossref | GoogleScholarGoogle Scholar |
Geenty KG, Brien FD, Hinch GN, Dobos RC, Refshauge G, McCaskill M, Ball AJ, Behrendt R, Gore KP, Savage DB, Harden S, Hocking-Edwards JE, Hart K, van der Werf JHJ (2014) Reproductive performance in the Sheep CRC Information Nucleus using artificial insemination across different sheep-production environments in southern Australia. Animal Production Science 54, 715–726.
| Reproductive performance in the Sheep CRC Information Nucleus using artificial insemination across different sheep-production environments in southern Australia.Crossref | GoogleScholarGoogle Scholar |
Gootwine E (2013) Meta-analysis of morphometric parameters of late-gestation fetal sheep developed under natural and artificial constraints. Journal of Animal Science 91, 111–119.
| Meta-analysis of morphometric parameters of late-gestation fetal sheep developed under natural and artificial constraints.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXjsFKit78%3D&md5=b9d8b4e575e857d97cf11068b4bb9f9dCAS | 23404988PubMed |
Greentree C, Saunders G, McLeod L, Hone J (2000) Lamb predation and fox control in south-eastern Australia. Journal of Applied Ecology 37, 935–943.
| Lamb predation and fox control in south-eastern Australia.Crossref | GoogleScholarGoogle Scholar |
Haughey KG (1973a) Cold injury in newborn lambs. Australian Veterinary Journal 49, 554–563.
| Cold injury in newborn lambs.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaE2c%2Fps1WhtQ%3D%3D&md5=741e17420ec631131a4e1ca3a03b1359CAS | 4777212PubMed |
Haughey KG (1973b) Vascular abnormalities in the central nervous system associated with perinatal lamb mortality. 1. Pathology. Australian Veterinary Journal 49, 1–8.
| Vascular abnormalities in the central nervous system associated with perinatal lamb mortality. 1. Pathology.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaE3s7jt1aisA%3D%3D&md5=71e5c25baf7efaf65c299ed5d41d6d17CAS | 4734726PubMed |
Haughey KG (1973c) Vascular abnormalities in the central nervous system associated with perinatal lamb mortality. 2. Association of the abnormalities with recognised lesions. Australian Veterinary Journal 49, 9–15.
| Vascular abnormalities in the central nervous system associated with perinatal lamb mortality. 2. Association of the abnormalities with recognised lesions.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaE3s7jt1ahsQ%3D%3D&md5=e619f1c1deba7cbc1b9b391e0d2b6659CAS | 4734729PubMed |
Haughey KG (1980) The role of birth in the pathogenesis of meningeal haemorrhage and congestion in newborn lambs. Australian Veterinary Journal 56, 49–56.
| The role of birth in the pathogenesis of meningeal haemorrhage and congestion in newborn lambs.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaL3M%2Fmt1Wrsg%3D%3D&md5=c9b10cd5c19c37210d4a5924e2d60c06CAS | 7436889PubMed |
Haughey KG (1982) Postnatal mortality, bodyweight gain and wool production to two years of age of lambs surviving caesarean or stressful vaginal birth. Australian Veterinary Journal 58, 173–180.
| Postnatal mortality, bodyweight gain and wool production to two years of age of lambs surviving caesarean or stressful vaginal birth.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaL3s%2FkvVSktg%3D%3D&md5=3435cdbc9149ce1958549f955dbcf83dCAS | 7138430PubMed |
Haughey KG (1983) New insights into rearing failure and perinatal lamb mortality. In ‘Refresher Course for Veterinarians, Proceedings No. 67’. pp. 135–147. (The Post Graduate Committee in Veterinary Science, University of Sydney: Sydney)
Haughey KG (1985) Maternal and foetal factors in lamb survival. Australian Veterinary Journal 62, 148
| Maternal and foetal factors in lamb survival.Crossref | GoogleScholarGoogle Scholar |
Hight GK, Jury KE (1970) Hill country sheep production. New Zealand Journal of Agricultural Research 13, 735–752.
| Hill country sheep production.Crossref | GoogleScholarGoogle Scholar |
Hinch GN, Brien F (2014) Lamb survival in Australian flocks: a review. Animal Production Science 54, 656–666.
| Lamb survival in Australian flocks: a review.Crossref | GoogleScholarGoogle Scholar |
Hinch GN, Davis GH, Crosbie SF, Kelly RW, Trotter RW (1986) Causes of lamb mortality in two highly prolific Booroola crossbred flocks and a Romney flock. Animal Reproduction Science 12, 47–61.
| Causes of lamb mortality in two highly prolific Booroola crossbred flocks and a Romney flock.Crossref | GoogleScholarGoogle Scholar |
Holst, PJ (2004) ‘Lamb autopsy: notes on a procedure for determining cause of death.’ (NSW Agriculture)
Holst PJ, Fogarty NM, Hopkins DL, Stanley DF (1997) Lamb survival of Texel and Poll Dorset crossbred lambs. In ‘Proceedings of the Association for the Advancement of Animal Breeding and Genetics’, Dubbo. pp. 313–316.
Holst PJ, Fogarty NM, Stanley DF (2002) Birth weights, meningeal lesions, and survival of diverse genotypes of lambs from Merino and crossbred ewes. Australian Journal of Agricultural Research 53, 175–181.
| Birth weights, meningeal lesions, and survival of diverse genotypes of lambs from Merino and crossbred ewes.Crossref | GoogleScholarGoogle Scholar |
Hughes KL, Hartley WJ, Haughey KG, McFarlane D (1964) A study of perinatal mortality of lambs from the Oberon, Orange and Monaro districts of NSW. Proceedings of the Australian Society of Animal Production 5, 92–99.
Jefferies BC (1961) Body condition scoring and its use in management. Tasmanian Journal of Agriculture 32, 19–21.
Kelly RW (1992) Lamb mortality and growth to weaning in commercial Merino flocks in Western Australia. Australian Journal of Agricultural Research 43, 1399–1416.
| Lamb mortality and growth to weaning in commercial Merino flocks in Western Australia.Crossref | GoogleScholarGoogle Scholar |
Kenyon PR, Revell DK, Morris ST (2006a) Mid-pregnancy shearing can increase birthweight and survival to weaning of multiple-born lambs under commercial conditions. Australian Journal of Experimental Agriculture 46, 821–825.
| Mid-pregnancy shearing can increase birthweight and survival to weaning of multiple-born lambs under commercial conditions.Crossref | GoogleScholarGoogle Scholar |
Kenyon PR, Sherlock RG, Morris ST, Morel PCH (2006b) The effect of mid- and late-pregnancy shearing of hoggets on lamb birthweight, weaning weight, survival rate, and wool follicle and fibre characteristics. Australian Journal of Agricultural Research 57, 877–882.
| The effect of mid- and late-pregnancy shearing of hoggets on lamb birthweight, weaning weight, survival rate, and wool follicle and fibre characteristics.Crossref | GoogleScholarGoogle Scholar |
Kleemann DO, Walker SK (2005) Fertility in South Australian commercial Merino flocks: sources of reproductive wastage. Theriogenology 63, 2075–2088.
| Fertility in South Australian commercial Merino flocks: sources of reproductive wastage.Crossref | GoogleScholarGoogle Scholar | 15826674PubMed |
Knight TW, Lynch PR, Hall DRH, Hockey H-UP (1988) Identification of factors contributing to the improved lamb survival in Marshall Romney sheep. New Zealand Journal of Agricultural Research 31, 259–271.
| Identification of factors contributing to the improved lamb survival in Marshall Romney sheep.Crossref | GoogleScholarGoogle Scholar |
Landa A, Gudvangen K, Swenson JE, Røskaft E (1999) Factors associated with wolverine Gulo gulo predation on domestic sheep. Journal of Applied Ecology 36, 963–973.
| Factors associated with wolverine Gulo gulo predation on domestic sheep.Crossref | GoogleScholarGoogle Scholar |
Le Floch E, Refshauge G, van de Ven R, Morgan JE, Hopkins DL (2010) Border Leicester × Merino dams lose fewer lambs to starvation than Merino dams. In ‘Australian Society of Animal Production 28th biennial conference, Armidale, NSW’. Vol. 28, 85.
Lugton IW (1993) Diet of red foxes (Vulpes vulpes) in south-west New South Wales, with relevance to lamb predation. The Rangeland Journal 15, 39–47.
| Diet of red foxes (Vulpes vulpes) in south-west New South Wales, with relevance to lamb predation.Crossref | GoogleScholarGoogle Scholar |
Mann TLJ (1968) A comparison of lamb survival in fox proof and unprotected enclosures. Proceedings of the Australian Society for Animal Production 7, 250–254.
Martin P, Phillips P (2011) Australian lamb: Financial performance of slaughter lamb producing farms, 2008–09 to 2010–11. ABARES report prepared for Meat and Livestock Australia, Canberra.
McCance I, Alexander G (1959) The onset of lactation in the Merino ewe and its modification by nutritional factors. Australian Journal of Agricultural Research 10, 699–719.
| The onset of lactation in the Merino ewe and its modification by nutritional factors.Crossref | GoogleScholarGoogle Scholar |
McFarlane D (1955) Neonatal lamb mortality in the Gisborne area. Proceedings of the New Zealand Society of Animal Production 15, 104–119.
McFarlane D (1965) Perinatal lamb losses. 1. An autopsy method for the investigation of perinatal losses. New Zealand Veterinary Journal 13, 116–135.
| Perinatal lamb losses. 1. An autopsy method for the investigation of perinatal losses.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaF28%2FotVeqsw%3D%3D&md5=7d4a06184992f1b42b8a681a9ad6d011CAS | 5216702PubMed |
Moule GR (1954) Observations on mortality amongst lambs in Queensland. Australian Veterinary Journal 30, 153–171.
| Observations on mortality amongst lambs in Queensland.Crossref | GoogleScholarGoogle Scholar |
Murphy PM, McNeill DM, Fisher JS, Lindsay DR (1996) Strategic feeding of merino ewes in late pregnancy to increase colostrum production. Proceedings for the Australian Society of Animal Production 21, 227–230.
Plant JW (1981) Field investigations into reproductive wastage in sheep. In ‘Refresher course for veterinarians, proceedings no. 58’. pp. 411–438. (The Post Graduate Committee in Veterinary Science, University of Sydney: Sydney)
Purser AF, Young GB (1964) Mortality among twin and single lambs. Animal Production 6, 321–329.
| Mortality among twin and single lambs.Crossref | GoogleScholarGoogle Scholar |
R Development Core Team (2010) R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. Available at http://www.R-project.org/ [Verified 9 November 2015]
Refshauge PG, Hatcher S, Hopkins DL, Hinch GN, Nielsen S (2007) Does phenotypic selection for fleece weight reduce lamb survival? Proceedings of the Association for the Advancement of Animal Breeding and Genetics 17, 561–564.
Russel AJF, Doney JM, Gunn RG (1969) Subjective assessment of body fat in live sheep. The Journal of Agricultural Science 72, 451–454.
| Subjective assessment of body fat in live sheep.Crossref | GoogleScholarGoogle Scholar |
Saunders GR, Gentle MN, Dickman CR (2010) The impacts and management of foxes Vulpes vulpes in Australia. Mammal Review 40, 181–211.
| The impacts and management of foxes Vulpes vulpes in Australia.Crossref | GoogleScholarGoogle Scholar |
Symonds ME, Bryant MJ, Clarke L, Darby CJ, Lomax MA (1992) Effect of maternal cold exposure on brown adipose tissue and thermogenesis in the neonatal lamb. The Journal of Physiology 455, 487–502.
| Effect of maternal cold exposure on brown adipose tissue and thermogenesis in the neonatal lamb.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaK3s7jt1OjsA%3D%3D&md5=bfbb9af28ec34230d9017f1c78da7b3dCAS | 1484361PubMed |
Vermorel M, Vernet J (1985) Major factors affecting thermogensis and cold resistance of newborn lambs. In ‘Factors affecting the survival of newborn lambs’. (Eds G Alexander, JD Barker, J Slee) pp. 35–44. (Commission of the European Communities: Brussels)
Watson RH (1957) Wastage in reproduction in Merino sheep. Australian Veterinary Journal 33, 307–310.
| Wastage in reproduction in Merino sheep.Crossref | GoogleScholarGoogle Scholar |
Woolliams C, Wiener G, Macleod NSM (1983a) The effect of breed, breeding system and other factors on lamb mortality. 3. Factors influencing the incidence of weakly lambs as a cause of death. Journal of Agricultural Science, Cambridge 100, 563–570.
| The effect of breed, breeding system and other factors on lamb mortality. 3. Factors influencing the incidence of weakly lambs as a cause of death.Crossref | GoogleScholarGoogle Scholar |
Woolliams C, Wiener G, Macleod NSM (1983b) The effects of breed, breeding system and other factors on lamb mortality. 2. Factors influencing the incidence of delayed birth, dystokia, congenital defects and miscellaneous causes of death. Journal of Agricultural Science, Cambridge 100, 553–561.
| The effects of breed, breeding system and other factors on lamb mortality. 2. Factors influencing the incidence of delayed birth, dystokia, congenital defects and miscellaneous causes of death.Crossref | GoogleScholarGoogle Scholar |
Young JM, Thompson AN, Curnow M, Oldham CM (2011) Whole-farm profit and the optimum maternal liveweight profile of Merino ewe flocks lambing in winter and spring are influenced by the effects of ewe nutrition on the progeny’s survival and lifetime wool production. Animal Production Science 51, 821–833.
| Whole-farm profit and the optimum maternal liveweight profile of Merino ewe flocks lambing in winter and spring are influenced by the effects of ewe nutrition on the progeny’s survival and lifetime wool production.Crossref | GoogleScholarGoogle Scholar |
