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Genetic parameters for lamb weight at different ages and wool production in Baluchi sheep

Published online by Cambridge University Press:  02 September 2010

M. H. Yazdi ,
G. Engström ,
A. Näsholm ,
K. Johansson ,
H. Jorjani  and
L.-E. Liljedah
M. H. Yazdi
Affiliation:
Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Box 7023, S-750 07 Uppsala, Sweden
G. Engström
Affiliation:
Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Box 7023, S-750 07 Uppsala, Sweden
A. Näsholm
Affiliation:
Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Box 7023, S-750 07 Uppsala, Sweden
K. Johansson
Affiliation:
Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Box 7023, S-750 07 Uppsala, Sweden
H. Jorjani
Affiliation:
Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Box 7023, S-750 07 Uppsala, Sweden
L.-E. Liljedah
Affiliation:
Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Box 7023, S-750 07 Uppsala, Sweden
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Abstract

The Baluchi breed is the most common native breed of Iran adapted to harsh environments in the eastern parts of the country. The data used in the present study, collected from two research flocks at the Abbasabad sheep breeding station in north-east Iran, included 20 534 animals descended from 363 sires, 5992 dams, 282 maternal grandsires, and 2865 maternal granddams during the period 1966 to 1989. The traits recorded were: birth weight (BW), weaning weight (WW), weight at 6 months (W6), weight at 12 months (YW), pre-weaning gain (WG), post-weaning gain (PWG), lamb fleece weight (LFW), ewe fleece weight sheared before first joining (FW1) and adult ewe fleece weight (FW). Genetic parameters, estimated with restricted maximum likelihood and a two-trait animal model, were similar in the two flocks. Direct heritabilities for the various body weight traits were moderate and varied between 0·13 and 0·32, while the maternal heritabilities were low and varied between 0·01 and 0·12. Direct and maternal genetic correlations between WW and weights at later ages were moderate to high (0·59 to 0·96). Direct heritabilities of weight gain measures varied between 0·12 and 0·19, while no significant maternal influence on either of these weight gain measures could be detected. The estimates of direct genetic correlation between WG and PWG were positive and varied between 0·54 and 0·74, while negative maternal genetic correlation (0·17 on average) between WG and PWG was detected. For LFW, direct heritability was low and no maternal heritability could be shown. For FW1, both direct and maternal genetic influences were demonstrated (0·07 to 0·26). Direct genetic correlation between LFW and FW1 was very low and close to zero, while maternal genetic correlation was positive and relatively high (0·72 on average). The relative contributions to phenotypic variance from variance components due to common environmental effects ranged from 0·01 to 0·15 for all traits. The repeatability of FW was low (0·03 to 0·12).

Keywords

animal modelsgrowthlambsmaternal effectsheepvariance components
Type
Research Article
Information
Animal Science , Volume 65 , Issue 2 , October 1997 , pp. 247 - 255
Copyright
Copyright © British Society of Animal Science 1997

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References

Atkins, K. D. 1986. A genetic analysis of the components of lifetime productivity in Scottish Blackface sheep. Animal Production 43:405–419.Google Scholar
Bhat, P. N. 1987. Principles for animal improvement in the tropics — sheep and goats: Asian experiences. In Animal genetic resources: strategies for improved use and conservation (ed. Hodges, J.), FAO animal production and health paper no. 66, pp. 89–124.Google Scholar
Boujenane, I. and Kerfal, M. 1990. Estimates of genetic and phenotypic parameters for growth traits of D'man lambs. Animal Production 51:173–178.Google Scholar
Brash, L. D., Fogarty, N. M., Barwick, S. A. and Gilmour, A. R. 1994a. Genetic parameters for Australian maternal and dual-purpose meatsheep breeds. I. Liveweight, wool production and reproduction in Border Leicester and related types. Australian Journal of Agricultural Research 45: 459–468.CrossRefGoogle Scholar
Brash, L. D., Fogarty, N. M. and Gilmour, A. R. 1994b. Genetic parameters for Australian maternal and dual-purpose meatsheep breeds. II. Liveweight, wool and reproduction in Corriedale sheep. Australian Journal of Agricultural Research 45:469–480.CrossRefGoogle Scholar
Burfening, P. J. and Kress, D. D. 1993. Direct and maternal effects on birth and weaning weight in sheep. Small Ruminant Research 10:153–163.CrossRefGoogle Scholar
Food and Agriculture Organization. 1994. Yearbook production, volume 48. Food and Agriculture Organization of the United Nations, Rome.Google Scholar
Gjedrem, T. 1967. Phenotypic and genetic parameters for weights of lambs at five ages. Acta Agriculturae Scandinavica 17:199–216.CrossRefGoogle Scholar
Hall, G. D., Gilmour, A. R. and Fogarty, N. M. 1994. Variation in reproduction and production of Poll Dorset ewes. Australian Journal of Agricultural Research 45:415–426.CrossRefGoogle Scholar
Jensen, J. and Madsen, P. 1993. A user's guide to DMU, a package for analyzing multivariate mixed models. National Institute of Animal Science Research Center Foulum, Box 39 8830, Tjele, Denmark.Google Scholar
Maria, G. A., Boldman, K. G. and Van Vleck, L. D. 1993. Estimates of variances due to direct and maternal effects for growth traits of Romanov sheep. Journal of Animal Science 71: 845–849.CrossRefGoogle ScholarPubMed
Martin, T. G., Sales, D. I., Smith, C. and Nicholson, D. 1980. Phenotypic and genetic parameters for lamb weights in a synthetic line of sheep. Animal Production 30: 261–269.Google Scholar
Mavrogenis, A. P., Louca, A. and Robison, O. W. 1980. Estimates of genetic parameters for pre-weaning and postweaning growth traits of Chios lambs. Animal Production 30: 271–276.Google Scholar
Näsholm, A. and Danell, Ö. 1996. Genetic relationships of lamb weight, maternal ability, and mature ewe weight in Swedish finewool sheep. Journal of Animal Science 74: 329–339.CrossRefGoogle ScholarPubMed
Olivier, J. J. 1994. Direct and maternal variance component estimates for clean fleece weight, body weight and mean fibre diameter in the Grootfontein Merino stud. South African Journal of Animal Science 24:122–124.Google Scholar
Robison, O. W. 1981. The influence of maternal effects on the efficiency of selection — a review. Livestock Production Science 8: 121–137.CrossRefGoogle Scholar
Snyman, M. A., Erasmus, G. J., Wyk, J. B. van and Olivier, J. J. 1995. Direct and maternal (co)variance components and heritability estimates for body weight at different ages and fleece traits in Afrino sheep. Livestock Production Science 44: 229–235.CrossRefGoogle Scholar
Statistical Analysis Systems Institute. 1985. SAS user's guide: statistics, version 5. SAS Institute Inc., Cary, NC.Google Scholar
Tosh, J. J. and Kemp, R. A. 1994. Estimation of variance components for lamb weights in three sheep populations. Journal of Animal Science 72:1184–1190.CrossRefGoogle ScholarPubMed
Young, S. S. Y., Brown, G. H., Turner, H. N. and Dolling, C. H. S. 1965. Genetic and phenotypic parameters for body weight and greasy fleece weight at weaning in Australian Merino sheep. Australian Journal of Agricultural Research 16: 997–1009.CrossRefGoogle Scholar
Young, S. S. Y., Turner, H. N. and Dolling, C. H. S. 1960. Comparison of estimates of repeatability and heritability for some production traits in Merino rams and ewes. II. Heritability. Australian Journal of Agricultural Research 11: 604–617.CrossRefGoogle Scholar