Growth and carcass characteristics of crossbred lambs in various production systems
N. M. Fogarty A D and J. G. Mulholland B CA NSW Department of Primary Industries, Orange Agricultural Institute, Orange, NSW 2800, Australia.
B NSW Department of Primary Industries, Agricultural Research Institute, Wagga Wagga, NSW 2650, Australia.
C Present address: 13A Bonaira Street, Kiama NSW 2533, Australia.
D Corresponding author. Email: neal.fogarty@dpi.nsw.gov.au
Animal Production Science 52(5) 373-381 https://doi.org/10.1071/AN11336
Submitted: 7 December 2011 Accepted: 10 February 2012 Published: 10 May 2012
Abstract
Lamb growth, carcass and pelt measurements are reported from 5775 lambs born to Border Leicester × Merino (BLM) and Hyfer (Dorset × Merino composite) ewes joined to Dorset, Suffolk and Hyfer rams in three lamb-production systems at Cowra and Wagga Wagga over 5 years. The production systems involved lambings at different seasons of the year and increasing levels of intensification from autumn annual joining, spring joining with a backup mating for non-pregnant ewes, to an accelerated 8-monthly lambing system. Lambs from BLM ewes were 0.7 kg heavier at birth and grew 3% faster and reached slaughter, at 18 kg carcass weight, 1–2 weeks earlier than did lambs from Hyfer ewes (P < 0.01). The advantage in growth rate of lambs from BLM compared with Hyfer ewes was greater for lambs born in November. These lambs had poorer growing conditions over the summer months, with 22% lower growth rate and taking 5 weeks longer to reach slaughter than did lambs born in March or August. There was no difference between Dorset and Suffolk sire breeds for any lamb growth traits, with lambs from Hyfer sires growing 7% slower. Ram and cryptorchid lambs reached slaughter 1 week earlier than did wethers, with ewes a further 9 days later (P < 0.01). Sex differences were maximised when lamb growth was greatest. There were no differences in carcass fat measurements between ram and cryptorchid lambs, although both were considerably leaner than wethers (2.2–3.0 mm fat at the GR site), which were 1.3–2.1 mm leaner than ewes at 18-kg carcass weight. The range in average growth rate of progeny of the BLM ewes from the 12 different source flocks at Cowra and Wagga Wagga was 10–14% of the mean which was twice the difference in average growth rate of progeny from the BLM and Hyfer dams. There was also significant variation among the BLM source flocks for carcass fat measurements. Lamb progeny from the different sire- and dam-breed combinations had varying levels of heterozygosity. There appears to be little loss of heterosis or hybrid vigour for lamb growth, although the sire breed × dam breed interaction was significant (P < 0.01) for age at slaughter at Wagga Wagga, in which the ranking of the lamb types was consistent with the levels of heterozygosity. The estimates of between-lambing repeatability for the ewes were highest for birthweight (0.35 Cowra and 0.27 Wagga Wagga) and declined at later ages (0.26–0.17), with lower estimates for carcass traits.
Additional keywords: breeds, fat level, hybrid vigour, lambing season, pelt weight, repeatability.
References
Atkins KD, Thompson JM (1979) Carcass characteristics of heavyweight lambs 1. Growth and carcass measurements. Australian Journal of Agricultural Research 30, 1197–1205.| Carcass characteristics of heavyweight lambs 1. Growth and carcass measurements.Crossref | GoogleScholarGoogle Scholar |
Banks RG (1990) LAMBPLAN: an integrated approach to genetic improvement for the Australian lamb industry. Proceedings of the Australian Association of Animal Breeding and Genetics 8, 237–240.
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.
Burfening PJ, Kress DD (1992) Most probable producing ability of ewes in relation to early growth traits. Small Ruminant Research 7, 67–74.
| Most probable producing ability of ewes in relation to early growth traits.Crossref | GoogleScholarGoogle Scholar |
Donnelly JR, McKinney GT, Morley FHW (1985) The productivity of breeding ewes grazing on lucerne or grass and clover pastures on the tablelands of southern Australia. IV. Lamb growth. Australian Journal of Agricultural Research 36, 469–481.
| The productivity of breeding ewes grazing on lucerne or grass and clover pastures on the tablelands of southern Australia. IV. Lamb growth.Crossref | GoogleScholarGoogle Scholar |
Fletcher IC, Geytenbeek PE, Allden WG (1970) Interaction between the effects of nutrition and season of mating on reproductive performance in crossbred ewes. Australian Journal of Experimental Agriculture and Animal Husbandry 10, 393–396.
| Interaction between the effects of nutrition and season of mating on reproductive performance in crossbred ewes.Crossref | GoogleScholarGoogle Scholar |
Fogarty NM, Dickerson GE, Young LD (1985) Lamb production and its components in pure breeds and composite lines. III. Genetic parameters. Journal of Animal Science 60, 40–57.
Fogarty NM, Hall DG, Atkinson WR (1992) Productivity of three crossbred ewe types mated naturally at 8-monthly intervals over two years. Australian Journal of Agricultural Research 43, 1819–1832.
| Productivity of three crossbred ewe types mated naturally at 8-monthly intervals over two years.Crossref | GoogleScholarGoogle Scholar |
Fogarty NM, Brash LD, Gilmour AR (1994) Genetic parameters for reproduction and lamb production and their components and liveweight, fat depth and wool production in Hyfer sheep. Australian Journal of Agricultural Research 45, 443–457.
| Genetic parameters for reproduction and lamb production and their components and liveweight, fat depth and wool production in Hyfer sheep.Crossref | GoogleScholarGoogle Scholar |
Fogarty NM, Hopkins DL, van de Ven R (2000a) Lamb production from diverse genotypes 1. Lamb growth and survival and ewe performance. Animal Science (Penicuik, Scotland) 70, 135–145.
Fogarty NM, Hopkins DL, van de Ven R (2000b) Lamb production from diverse genotypes 2. Carcass characteristics. Animal Science (Penicuik, Scotland) 70, 147–156.
Fogarty NM, Ingham VM, Gilmour AR, Cummins LJ, Gaunt GM, Stafford J, Hocking Edwards JE, Banks RG (2005a) Genetic evaluation of crossbred lamb production. 1. Breed and fixed effects for birth and weaning weight of first-cross lambs, gestation length, and reproduction of base ewes. Australian Journal of Agricultural Research 56, 443–453.
| Genetic evaluation of crossbred lamb production. 1. Breed and fixed effects for birth and weaning weight of first-cross lambs, gestation length, and reproduction of base ewes.Crossref | GoogleScholarGoogle Scholar |
Fogarty NM, Ingham VM, McLeod L, Gaunt GM, Cummins LJ (2005b) Variation among maternal sires for lamb and wool gross margin performance of their crossbred daughters. Proceedings of the Association for the Advancement of Animal Breeding and Genetics 16, 60–63.
Gilmour AR, Gogel BJ, Cullis BR, Thompson R (2009) ‘ASReml user guide release 3.0.’ (VSN International Ltd: Hemel Hempstead, HP1 1ES, UK.) Available at www.vsni.co.uk [verified 19 April 2012]
Harris DC (1985) The New South Wales Meatsheep Testing Service: a project to develop a practical growth rate and fat depth testing facility for terminal meat breed ram producers. Proceedings of the Australian Association of Animal Breeding and Genetics 5, 120–127.
Holst PJ, Hegarty RS, Fogarty NM, Hopkins DL (1997) Fibre metrology and physical characteristics of lambskins from large Merino and crossbred lambs. Australian Journal of Experimental Agriculture 37, 509–514.
| Fibre metrology and physical characteristics of lambskins from large Merino and crossbred lambs.Crossref | GoogleScholarGoogle Scholar |
Hopkins DL, Gilbert KD, Saunders KL (1990) The performance of short scrotum and wether lambs born in winter or spring and run at pasture in northern Tasmania. Australian Journal of Experimental Agriculture 30, 165–170.
| The performance of short scrotum and wether lambs born in winter or spring and run at pasture in northern Tasmania.Crossref | GoogleScholarGoogle Scholar |
Hopkins DL, Jackson RB, Saunders KL (1991) Reduction of testicular parenchyma at marking: effect on lamb growth, carcass fatness and sexual development. Australian Journal of Experimental Agriculture 31, 597–601.
| Reduction of testicular parenchyma at marking: effect on lamb growth, carcass fatness and sexual development.Crossref | GoogleScholarGoogle Scholar |
Hopkins DL, Stanley DF, Martin LC, Ponnampalam EN, van de Ven R (2007) Sire and growth path effects on sheep meat production. 1. Growth and carcass characteristics. Australian Journal of Experimental Agriculture 47, 1208–1218.
| Sire and growth path effects on sheep meat production. 1. Growth and carcass characteristics.Crossref | GoogleScholarGoogle Scholar |
Kleemann DO, Dolling CHS, Ponzoni RW (1981) The contribution of maternal environment and lamb genotype to growth of lambs from Merino, Poll Dorset × Merino and Border Leicester × Merino ewes. Australian Journal of Agricultural Research 32, 965–973.
| The contribution of maternal environment and lamb genotype to growth of lambs from Merino, Poll Dorset × Merino and Border Leicester × Merino ewes.Crossref | GoogleScholarGoogle Scholar |
Lee GJ (1986a) Growth and carcass characteristics of ram and wether lambs fed at two levels of nutrition. Australian Journal of Experimental Agriculture 26, 275–278.
| Growth and carcass characteristics of ram and wether lambs fed at two levels of nutrition.Crossref | GoogleScholarGoogle Scholar |
Lee GJ (1986b) Growth and carcass characteristics of ram, cryptorchid and wether Border Leicester × Merino lambs: effects of increasing carcass weight. Australian Journal of Experimental Agriculture 26, 153–157.
| Growth and carcass characteristics of ram, cryptorchid and wether Border Leicester × Merino lambs: effects of increasing carcass weight.Crossref | GoogleScholarGoogle Scholar |
Lee GJ, Harris DC, Ferguson BD, Jelbart RA (1990) Growth and carcass fatness of ewe, ram and cryptorchid crossbred lambs reared at pasture: effects of weaning age. Australian Journal of Experimental Agriculture 30, 743–747.
| Growth and carcass fatness of ewe, ram and cryptorchid crossbred lambs reared at pasture: effects of weaning age.Crossref | GoogleScholarGoogle Scholar |
Thimonier J, Bindon BM, Piper LR, Curtis YM, Cheers MA, Farrell RM (1985) Seasonal changes in spontaneous oestrus and ovulation in Border Leicester × Merino and Dorset × Merino ewes. International Journal of Sheep and Wool Science 33, 28–31.
