Performance of sheep systems grazing perennial pastures. 3. Fertility, fecundity and lamb survival
Susan M. Robertson A B C and Michael A. Friend A B C D
+ Author Affiliations
- Author Affiliations
A Graham Centre for Agricultural Innovation (Charles Sturt University and NSW Department of Primary Industries), Albert Pugsley Place, Wagga Wagga, NSW 2678, Australia.
B Cooperative Research Centre for Future Farm Industries, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.
C School of Animal and Veterinary Sciences, Charles Sturt University, Locked Bag 588, Wagga Wagga, NSW 2678, Australia.
D Corresponding author. Email: mfriend@csu.edu.au
Animal Production Science 60(3) 414-422 https://doi.org/10.1071/AN18557
Submitted: 4 September 2018 Accepted: 6 May 2019 Published: 31 December 2019
Abstract
Management system has the potential to alter the reproductive output of sheep flocks and thereby farm profit. A study was conducted between 2006 and 2010 to evaluate the reproductive performance of four management systems with differing combinations of time of lambing, stocking rate and ram breed, while grazing at a similar midwinter stocking rate (dry-sheep equivalents per hectare of 8, 10.2, 13, 11.2 and 11.2 in the successive seasons 2006–2010). Three systems, winter lambing Merino (WLM), split lambing (SL) and later lambing (LL), grazed replicated farmlets comprising pastures that were 20% lucerne (Medicago sativa), 20% tall fescue (Festuca arundinacea) and 60% phalaris (Phalaris aquatica). A fourth system (high lucerne (HL)) grazed farmlets of 40% lucerne, 15% tall fescue and 45% phalaris. All systems used Merino ewes: in WLM mated to Merino rams, lambing in July; in SL half of the ewes lambing to terminal-breed rams in July, the other half lambing to Merino rams in September; and in LL and HL lambed in September, half to terminal-breed and half to Merino rams. The number of lambs weaned per ewe joined was 10% higher (P < 0.05) in the WLM system (0.99 ± 0.03) than in the September-lambing systems LL and HL, largely a result of a higher number of fetuses per ewe and despite lower (P < 0.05) lamb survival to marking in some years. The SL system weaned a similar (P > 0.05) number of lambs per ewe (0.95 ± 0.03) to all other systems. However, the number of lambs weaned per hectare was least in WLM (4.6 ± 0.2), lower than in the HL and LL systems by 2.7 lambs/ha because of a lower stocking rate. The ranking of systems for fetal number and lamb survival was not consistent among years. Spring-lambing systems produced more lambs per hectare because of a higher stocking rate but fewer lambs per ewe than the WLM system. System differences in pregnancy rate, fecundity and lamb survival were not consistent between years.
Additional keywords: nutrition, reproduction.
References
Alexander G (1962) Temperature regulation in the new-born lamb. IV. The effect of wind and evaporation of water from the coat on metabolic rate and body temperature. Australian Journal of Agricultural Research 13, 82–99.| Temperature regulation in the new-born lamb. IV. The effect of wind and evaporation of water from the coat on metabolic rate and body temperature.Crossref | GoogleScholarGoogle Scholar |
Broster JC, Robertson SM, Dehaan RL, King BJ, Friend MA (2012) Evaluating seasonal risk and the potential for windspeed reductions to reduce chill index at six locations using GrassGro. Animal Production Science 52, 921–928.
| Evaluating seasonal risk and the potential for windspeed reductions to reduce chill index at six locations using GrassGro.Crossref | GoogleScholarGoogle Scholar |
Cumming I (1977) Relationships in the sheep of ovulation rate with liveweight, breed, season and plane of nutrition. Australian Journal of Experimental Agriculture 17, 234–241.
| Relationships in the sheep of ovulation rate with liveweight, breed, season and plane of nutrition.Crossref | GoogleScholarGoogle Scholar |
Curnow M, Oldham CM, Behrendt R, Gordon DJ, Hyder MW, Rose IJ, Whale JW, Young JM, Thompson AN (2011) Successful adoption of new guidelines for the nutritional management of ewes is dependent on the development of appropriate tools and information. Animal Production Science 51, 851–856.
| Successful adoption of new guidelines for the nutritional management of ewes is dependent on the development of appropriate tools and information.Crossref | GoogleScholarGoogle Scholar |
Donnelly J (1984) The productivity of breeding ewes grazing on lucerne or grass and clover pastures on the tablelands of Southern Australia. III. Lamb mortality and weaning percentage. Australian Journal of Agricultural Research 35, 709–721.
| The productivity of breeding ewes grazing on lucerne or grass and clover pastures on the tablelands of Southern Australia. III. Lamb mortality and weaning percentage.Crossref | GoogleScholarGoogle Scholar |
Dun R, Ahmed W, Morrant A (1960) Annual reproductive rhythm in Merino sheep related to the choice of a mating time at Trangie, Central Western New South Wales. Australian Journal of Agricultural Research 11, 805–826.
| Annual reproductive rhythm in Merino sheep related to the choice of a mating time at Trangie, Central Western New South Wales.Crossref | GoogleScholarGoogle Scholar |
Fogarty NM, Hopkins DL, van de Ven R (2000) Lamb production from diverse genotypes. 1. Lamb growth and survival and ewe performance. Animal Science 70, 134–145.
Fogarty NM, Mulholland JG (2013) Annual lambing performance of crossbred ewes in out-of-season and accelerated lamb production systems. Animal Production Science 53, 1093–1100.
| Annual lambing performance of crossbred ewes in out-of-season and accelerated lamb production systems.Crossref | GoogleScholarGoogle Scholar |
Gulliver CE, Friend MA, King BJ, Wilkins JF, Clayton EH (2013) A higher proportion of female lambs when ewes were fed oats and cottonseed meal prior to and following conception. Animal Production Science 53, 464–471.
| A higher proportion of female lambs when ewes were fed oats and cottonseed meal prior to and following conception.Crossref | GoogleScholarGoogle Scholar |
Hatcher S, Eppleston J, Graham RP, McDonald J, Schlunke S, Watt B, Thornberry KJ (2008) Higher weaning weight improves postweaning growth and survival in young Merino sheep. Australian Journal of Experimental Agriculture 48, 966–973.
| Higher weaning weight improves postweaning growth and survival in young Merino sheep.Crossref | GoogleScholarGoogle Scholar |
Ho CKM, Jackson T, Harrison MT, Eckard RJ (2014) Increasing ewe genetic fecundity improves whole-farm production and reduces greenhouse gas emissions intensities: 2. Economic performance. Animal Production Science 54, 1248–1253.
| Increasing ewe genetic fecundity improves whole-farm production and reduces greenhouse gas emissions intensities: 2. Economic performance.Crossref | GoogleScholarGoogle Scholar |
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.
Jefferies BC (1961) Body condition scoring and its use in management. Tasmanian Journal of Agriculture 32, 19–21.
Kenyon PR, Hickson RE, Hutton PG, Morris ST, Stafford KJ, West DM (2012) Effect of twin-bearing ewe body condition score and late pregnancy nutrition on lamb performance. Animal Production Science 52, 483–490.
| Effect of twin-bearing ewe body condition score and late pregnancy nutrition on lamb performance.Crossref | GoogleScholarGoogle Scholar |
King BJ, Robertson SM, Friend MA, Wilkins JF (2010) Short-term grazing of lucerne and chicory increases ovulation rate in synchronised Merino ewes. Animal Reproduction Science 121, 242–248.
| Short-term grazing of lucerne and chicory increases ovulation rate in synchronised Merino ewes.Crossref | GoogleScholarGoogle Scholar | 20678872PubMed |
Kleemann DO, Walker SK (2005) Fertility in South Australian commercial Merino flocks: relationships between reproductive traits and environmental cues. Theriogenology 63, 2416–2433.
| Fertility in South Australian commercial Merino flocks: relationships between reproductive traits and environmental cues.Crossref | GoogleScholarGoogle Scholar | 15910923PubMed |
Kleemann DO, Grosser TI, Walker SK (2006) Fertility in South Australian commercial Merino flocks: aspects of management. Theriogenology 65, 1649–1665.
| Fertility in South Australian commercial Merino flocks: aspects of management.Crossref | GoogleScholarGoogle Scholar | 16256188PubMed |
Lindsay DR, Knight TW, Smith JF, Oldham CM (1975) Studies in ovine fertility in agricultural regions of Western Australia: ovulation rate, fertility and lambing performance. Australian Journal of Agricultural Research 26, 189–198.
| Studies in ovine fertility in agricultural regions of Western Australia: ovulation rate, fertility and lambing performance.Crossref | GoogleScholarGoogle Scholar |
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 | 5216702PubMed |
Nottle MB, Kleeman DO, Seamark RF (1997) Effect of previous undernutrition on the ovulation rate of merino ewes supplemented with lupin grain. Animal Reproduction Science 49, 29–36.
| Effect of previous undernutrition on the ovulation rate of merino ewes supplemented with lupin grain.Crossref | GoogleScholarGoogle Scholar | 9458947PubMed |
Oldham CM, Thompson AN, Ferguson MB, Gordon DJ, Kearney GA, Paganoni BL (2011) The birthweight and survival of Merino lambs can be predicted from the profile of liveweight change of their mothers during pregnancy. Animal Production Science 51, 776–783.
| The birthweight and survival of Merino lambs can be predicted from the profile of liveweight change of their mothers during pregnancy.Crossref | GoogleScholarGoogle Scholar |
Parr RA, Davis IF, Fairclough RJ, Miles MA (1987) Overfeeding during early pregnancy reduces peripheral progesterone concentration and pregnancy rate in sheep. Journal of Reproduction and Fertility 80, 317–320.
| Overfeeding during early pregnancy reduces peripheral progesterone concentration and pregnancy rate in sheep.Crossref | GoogleScholarGoogle Scholar | 3598967PubMed |
Reeve JL, Sharkey MJ (1980) Effect of stocking rate, time of lambing and inclusion of lucerne on prime lamb production in north-east Victoria. Australian Journal of Experimental Agriculture 20, 637–653.
Robertson SM, Friend MA (2019) Performance of sheep systems grazing perennial pastures. 2. Wool quality and lamb growth. Animal Production Science.
| Performance of sheep systems grazing perennial pastures. 2. Wool quality and lamb growth.Crossref | GoogleScholarGoogle Scholar |
Robertson SM, Broster JC, Friend MA (2019) Performance of sheep systems grazing perennial pastures. 1. Pasture persistence and enterprise productivity. Animal Production Science.
| Performance of sheep systems grazing perennial pastures. 1. Pasture persistence and enterprise productivity.Crossref | GoogleScholarGoogle Scholar |
Robertson SM, King BJ, Broster JC, Friend MA (2012) The survival of lambs in shelter declines at high stocking intensities. Animal Production Science 52, 497–501.
| The survival of lambs in shelter declines at high stocking intensities.Crossref | GoogleScholarGoogle Scholar |
Robertson SM, Clayton EH, King BJ, Knott S, Morgan B, Friend MA (2014a) Lucerne pasture ad libitum after day 7 post-insemination may increase embryo mortality in ewes. Animal Production in Australia 30, 66
Robertson SM, King BJ, Allworth MB, Rummery J, Friend MA (2014b) The effect of peri-conceptual grazing of live pasture on fetal numbers in unsynchronised ewes. Animal Production Science 54, 1008–1015.
| The effect of peri-conceptual grazing of live pasture on fetal numbers in unsynchronised ewes.Crossref | GoogleScholarGoogle Scholar |
Sackett S, McEachern S, Holmes P, Duff DC, Condon T (2004) AgInsights 2004: knowing the past and shaping the future. Final Report to MLA for Project SCSB. Meat and Livestock Australia, Sydney.
Schreurs NM, Kenyon PR, Mulvaney FJ, Morel PCH, West DM, Morris ST (2010) Effect of birthweight and birth rank on the survival of single and twin lambs born to ewe lambs. Animal Production Science 50, 460–464.
| Effect of birthweight and birth rank on the survival of single and twin lambs born to ewe lambs.Crossref | GoogleScholarGoogle Scholar |
Stevens D, Alexander G, Lynch JJ (1982) Lamb mortality due to inadequate care of twins by Merino ewes. Applied Animal Ethology 8, 243–252.
| Lamb mortality due to inadequate care of twins by Merino ewes.Crossref | GoogleScholarGoogle Scholar |
Sykes AR, Griffiths RG, Slee J (1976) Influence of breed, birthweight and weather on the body temperature of new-born lambs. Animal Production 22, 395–402.
| Influence of breed, birthweight and weather on the body temperature of new-born lambs.Crossref | GoogleScholarGoogle Scholar |
Warn L, Webb Ware J, Salmon L, Donnelly J, Alcock D (2006) Analysis of the profitability of sheep wool and meat enterprises in southern Australia. Final Report for Project 1.2.6. Sheep Cooperative Research Centre, University of New England, Armidale, NSW.
Winfield CG (1970) The effect of stocking intensity at lambing on lamb survival and ewe behaviour. Proceedings of the Australian Society of Animal Production 8, 291–296.
Young JM, Thompson AN, Kennedy AJ (2010) Bioeconomic modelling to identify the relative importance of a range of critical control points for prime lamb production systems in south-west Victoria. Animal Production Science 50, 748–756.
| Bioeconomic modelling to identify the relative importance of a range of critical control points for prime lamb production systems in south-west Victoria.Crossref | GoogleScholarGoogle Scholar |
