Animal Production Science Animal Production Science Society
Food, fibre and pharmaceuticals from animals
RESEARCH ARTICLE

Litter size at lambing influences genetic evaluation of maternal rearing ability

Kim L. Bunter A D , Andrew A. Swan A , Daniel J. Brown A , Forbes D. Brien B and Jennifer Smith C
+ Author Affiliations
- Author Affiliations

A Animal Genetics and Breeding Unit (AGBU)*, University of New England, Armidale, NSW 2351, Australia.

B School of Animal and Veterinary Sciences, University of Adelaide, Roseworthy, SA 5371, Australia.

C CSIRO Agriculture and Food, Armidale, NSW 2350, Australia.

D Corresponding author. Email: kbunter2@une.edu.au

Animal Production Science - https://doi.org/10.1071/AN16422
Submitted: 1 July 2016  Accepted: 7 November 2016   Published online: 27 April 2017

Abstract

The genetic parameters for maternal rearing-ability of ewes were investigated by ignoring or defining the rearing ability trait separately by litter-size class (singles versus multiples) using multi-generational data from three, fully pedigreed Merino flocks differing in prolificacy, production level and environment. Genetic correlations (ra) between litter size (LSIZE) and the percentage of lambs surviving (PLSURV) were more negative with an increasing mean flock litter size (ra: –0.21 ± 0.17 to –0.73 ± 0.08), while the corresponding range in phenotypic correlations (rp) was substantially lower (rp: –0.15 ± 0.01 to –0.33 ± 0.01). Rearing-ability traits defined separately by litter-size class were highly correlated (ra: 0.49 ± 0.19 to 0.64 ± 0.38), but not genetically identical traits in the most prolific flock. Defining rearing-ability traits separately by litter-size class reduced the antagonistic genetic correlations between LSIZE and PLSURV to between –0.39 ± 0.14 and 0.14 ± 0.28, through accommodating the change in mean and variance of PLSURV with LSIZE. Similarly, linear transformation (TSURV) of PLSURV within each litter size to a common mean and variance reduced the antagonistic trend in genetic correlations between LSIZE and TSURV to range between –0.05 ± 0.17 and –0.43 ± 0.13. Since genetic correlations are low to moderate between TSURV and LSIZE, it is possible to select for improvements in both the number of lambs born and lamb survival simultaneously. Defining rearing-ability traits separately by litter-size class and the role of transformation will be investigated further for improving the accuracy of genetic evaluation for rearing ability across a range of flocks, breeds and environmental conditions using more extensive industry data.

Additional keywords: correlation, heritability, lamb mortality, lamb survival, reproduction.


References

Amer PR, McEwan JC, Dodds KG, Davis GH (1999) Economic values for ewe prolificacy and lamb survival in New Zealand sheep. Livestock Production Science 58, 75–90.
Economic values for ewe prolificacy and lamb survival in New Zealand sheep.CrossRef |

Bodin L, Elsen JM (1989) Variability of litter size in French sheep following natural or induced ovulation. Animal Production 48, 535–541.
Variability of litter size in French sheep following natural or induced ovulation.CrossRef |

Brien FD, Hebart ML, Jaensch KS, Smith DH, Grimson RJ (2009) Genetics of lamb survival: a study of Merino resource flocks in South Australia. Proceedings of the Association for the Advancement of Animal Breeding and Genetics 18, 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 |

Brien FD, Hinch GN, van der Werf JHJ, Brown DJ, Swan AA (2011) Selection strategies for the genetic improvement of reproductive performance in sheep. Proceedings of the Association for the Advancement of Animal Breeding and Genetics 19, 151–158.

Brien FD, Cloete SWP, Fogarty NM, Greeff JC, Hebart ML, Hiendleder S, Hocking Edwards JE, Kelly JM, Kind KL, Kleemann DO, Plush KL, Miller DR (2014) A review of the genetic and epigenetic factors affecting lamb survival. Animal Production Science 54, 667–693.
A review of the genetic and epigenetic factors affecting lamb survival.CrossRef |

Brown DJ (2007) Variance components for lambing ease and gestation length in sheep. Proceedings of the Association for the Advancement of Animal Breeding and Genetics 17, 268–271.

Brown DJ, Huisman AE, Swan AA, Graser HU, Woolaston RR, Ball AJ, Atkins KD, Banks RG (2007) Genetic evaluation for the Australian sheep industry. Proceedings of the Association for the Advancement of Animal Breeding and Genetics 17, 187–194.

Brown DJ, Fogarty NM, Iker CL, Ferguson DM, Blache D, Gaunt GM (2016) Genetic evaluation of maternal behaviour and temperament in Australian sheep. Animal Production Science 56, 767–774.
Genetic evaluation of maternal behaviour and temperament in Australian sheep.CrossRef |

Bunter KL (2009) Managing consequences of increasing litter size: a genetic perspective. In ‘Manipulating pig production’. (Ed. RJ van Barneveld) pp. 149–156. (Australasian Pig Science Association: Melbourne)

Bunter KL, Brown DJ (2015) Revisiting total weaning weight as a selection criterion. Proceedings of the Association for the Advancement of Animal Breeding and Genetics 21, 201–204.

Bunter KL, Johnston DJ (2014) Genetic parameters for calf mortality in tropically adapted beef breeds managed in extensive Australian production systems. Animal Production Science 54, 50–59.
Genetic parameters for calf mortality in tropically adapted beef breeds managed in extensive Australian production systems.CrossRef |

Bunter KL, Swan AA, Purvis IW, Brown DJ (2016) Pregnancy scanning can be used as a source of data for genetic evaluation of reproductive traits of ewes. Animal Production Science 56, 679–689.
Pregnancy scanning can be used as a source of data for genetic evaluation of reproductive traits of ewes.CrossRef |

Burfening PJ (1993) Direct and maternal genetic effects on lamb survival. Small Ruminant Research 11, 267–274.
Direct and maternal genetic effects on lamb survival.CrossRef |

Cumming IA (1977) Relationships in the sheep of ovulation rate with liveweight, breed, season and plane of nutrition. Australian Journal of Experimental Agriculture and Animal Husbandry 17, 234–241.
Relationships in the sheep of ovulation rate with liveweight, breed, season and plane of nutrition.CrossRef |

Dohm MR (2002) Repeatability estimates do not always set an upper limit to heritability. Functional Ecology 16, 273–280.
Repeatability estimates do not always set an upper limit to heritability.CrossRef |

Dwyer CM (2008) Genetic and physiological determinants of maternal behaviour and lamb survival: implications for low-input sheep management. Journal of Animal Science 86, E246–E258.

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 | 1:STN:280:DC%2BC2cjgt1ersg%3D%3D&md5=cf6b073828272e504f79b9020665c58eCAS |

Gilmour AR, Gogel BJ, Cullis BR, Thompson R (2009) ‘ASREML user guide release 3.0.’ (VSN International: Hemel Hempstead, UK)

Hatcher S, Atkins KD, Safari E (2010) Lamb survival in Australian Merino sheep: a genetic analysis. Journal of Animal Science 88, 3198–3205.
Lamb survival in Australian Merino sheep: a genetic analysis.CrossRef | 1:STN:280:DC%2BC3cfgvVWitQ%3D%3D&md5=7f688f0093a87b915b7ebea56d7c0824CAS |

Hatcher S, Atkins KD, Mortimer SI (2014) Does the genetics of lamb survival differ between single and twin born Merino lambs? Paper 884. In ‘Proceedings 10th world congress on genetics applied to livestock production’, Vancouver, Canada.

Hebart ML, Brien FD, Jaensch KS, Smith DH, Walkom SF, Grimson RJ (2010) Genetics of reproductive efficiency: a study of Merino resource flocks in South Australia. Communication 05-05. In ‘Proceedings of the 9th world congress on genetics applied to livestock production’, Leipzig, Germany.

Hinch GN, Brien FD (2014) Lamb survival in Australian flocks: a review. Animal Production Science 54, 656–666.
Lamb survival in Australian flocks: a review.CrossRef |

Hocking Edwards JE, Copping KJ, Thompson AN (2011) Managing the nutrition of twin-bearing ewes during pregnancy using Lifetimewool recommendations increases production of twin lambs. Animal Production Science 51, 813–820.
Managing the nutrition of twin-bearing ewes during pregnancy using Lifetimewool recommendations increases production of twin lambs.CrossRef |

Janssens S, Vandepitte W, Bodin L (2004) Genetic parameters for litter size in sheep: natural versus hormone induced oestrus. Genetics, Selection, Evolution. 36, 543–562.
Genetic parameters for litter size in sheep: natural versus hormone induced oestrus.CrossRef |

Kelly OA, Hebart ML, Brien FD, Pitchford WS (2016) Lamb survival should be considered separate genetic traits across different birth types. In ‘Joint conference of the Australian and New Zealand Societies of Animal Production’. (Australian Society of Animal Production)

Kenney PA, Reeve JL, Baxter RW, Cumming IA (1980) Effect of different levels of the supplements lupin grain, lucerne, wheat, and wheat with urea and sulphur fed during mating in February to Border Leicester × Merino ewes in north-east Victoria. Australian Journal of Experimental Agriculture and Animal Husbandry 20, 15–19.
Effect of different levels of the supplements lupin grain, lucerne, wheat, and wheat with urea and sulphur fed during mating in February to Border Leicester × Merino ewes in north-east Victoria.CrossRef |

Kleemann DO, Walker SK, Ponzoni RW, Gifford DR, Walkley JRW, Smith DH, Grimson RJ, Jaensch KS, Walkom SF, Brien FD (2016) Effect of previous reproductive performance on current reproductive rate in South Australian Merino ewes. Animal Production Science 56, 716–725.
Effect of previous reproductive performance on current reproductive rate in South Australian Merino ewes.CrossRef |

Lane J, Jubb T, Shephard R, Webb-Ware L, Fordyce G (2015) ‘Priority list of endemic diseases for the red meat industries.’ (Meat and Livestock Australia: Sydney)

Lassoued N, Rekik M, Mahouachi M, Ben Hamouda M (2004) The effect of nutrition prior to and during mating on ovulation rate, reproductive wastage, and lambing rate in three sheep breeds. Small Ruminant Research 52, 117–125.
The effect of nutrition prior to and during mating on ovulation rate, reproductive wastage, and lambing rate in three sheep breeds.CrossRef |

Li L, Brown DJ (2016) Estimation of genetic parameters for lambing ease, birthweight and gestation length in Australian sheep. Animal Production Science 56, 934–940.
Estimation of genetic parameters for lambing ease, birthweight and gestation length in Australian sheep.CrossRef |

Piper LR, Bindon BM (1982) Genetic segregation for fecundity in Booroola Merino sheep. In ‘Proceedings of the world congress on sheep and cattle breeding’. (Eds RA Barton, WC Smith) pp. 395–400. (Dunmore Press: Auckland, New Zealand)

Plush KJ, Brien FD, Hebart ML, Hynd PI (2016) Thermogenesis and physiological maturity in neonatal lambs: a unifying concept in lamb survival. Animal Production Science 56, 736–745.
Thermogenesis and physiological maturity in neonatal lambs: a unifying concept in lamb survival.CrossRef |

Refshauge G, Brien FD, Hinch GN, van de Ven R (2016) Neonatal lamb mortality: factors associated with the death of Australian lambs. Animal Production Science 56, 726–735.
Neonatal lamb mortality: factors associated with the death of Australian lambs.CrossRef |

Safari E, Fogarty NM, Gilmour AR (2005) A review of genetic parameter estimates for wool, growth, meat and reproduction traits in sheep. Livestock Production Science 92, 271–289.
A review of genetic parameter estimates for wool, growth, meat and reproduction traits in sheep.CrossRef |

Safari E, Fogarty NM, Gilmour AR, Atkins KD, Mortimer SI, Swan AA, Brien FD, Greeff JC, van der Werf JHJ (2007) Across population genetic parameters for wool, growth and reproduction traits in Australian Merino sheep. 2. Estimates of heritability and variance components. Australian Journal of Agricultural Research 58, 177–184.

Schaeffer LR, Szkotnicki WJ (2015) ‘Genetic evaluations of sheep in Canada.’ (Centre for Genetic Improvement of Livestock, Department of Animal and Poultry Science, University of Guelph: Guelph, Ontario, Canada)

Stinchcombe JR, Rutter MT, Burdick DS, Tiffin P, Rausher MD, Mauricio R (2002) Testing for environmentally induced bias in phenotypic estimates of natural selection: theory and practice. American Naturalist 160, 511–523.
Testing for environmentally induced bias in phenotypic estimates of natural selection: theory and practice.CrossRef |

Swan AA, Piper LR, Brewer HG, Purvis IW (2001) Genetic variation in reproductive performance of fine wool Merinos. Proceedings of the Association for the Advancement of Animal Breeding and Genetics 14, 417–420.

Vanderick S, Auvray B, Newman SA, Dodds KG, Gengler N, Everett-Hincks JM (2015) Derivation of a new lamb survival trait for the New Zealand sheep industry. Journal of Animal Science 93, 3765–3772.
Derivation of a new lamb survival trait for the New Zealand sheep industry.CrossRef | 1:CAS:528:DC%2BC2MXhsVWksrzO&md5=755f5fd418b7a4b7bc7d014c044e2ffcCAS |



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