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The litter size and fertility of Finnish Landrace and Tasmanian Merino sheep and their reciprocal crosses

Published online by Cambridge University Press:  02 September 2010

R. B. Land ,
W. S. Russell  and
H. P. Donald
R. B. Land
Affiliation:
ARC Animal Breeding Research Organisation, Edinburgh EH9 3JQ
W. S. Russell
Affiliation:
ARC Animal Breeding Research Organisation, Edinburgh EH9 3JQ
H. P. Donald
Affiliation:
ARC Animal Breeding Research Organisation, Edinburgh EH9 3JQ
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Summary

Litter size (number of lambs born per female lambing) of adult female Finnish Landrace and Tasmanian Merino sheep mated to males of either breed was 2·9 and 1·0 respectively. Breed of ram had a direct effect on the conception rate of the ewes to which they were mated—22% of ewes mated to Merino rams returned to oestrus but only 10% of those mated to Finn rams—but not on their litter size.

A comparison of the reproductive performance of crossbred females with that of purebred contemporaries indicated that there was very little or no heterosis for litter size, the crossbreds being almost exactly intermediate between the parents. The proportion of females showing oestrus during the mating period, however, was lower in the Merinos than in the Finns and crossbreds. This was particularly noticeable in females put to the ram at around 6 months of age. Whereas 35 of 36 Finnish Landrace females and 46 of 49 crossbreds showed oestrus, only one of the 20 Merinos did so. At about 6 months of age therefore the crossbred females showed heterosis in the incidence of oestrus.

Type
Research Article
Information
Animal Production , Volume 18 , Issue 3 , June 1974 , pp. 265 - 271
Copyright
Copyright © British Society of Animal Science 1974

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References

REFERENCES

Donald, H. P. and Read, J. L. 1967. The performance of Finnish Landrace sheep in Britain. Anim. Prod. 9: 471–476.Google Scholar
Donald, H. P., Read, J. L. and Russell, W. S. 1968. A comparative trial of crossbred ewes by Finnish Landrace and other sires. Anim. Prod. 10: 413–421.Google Scholar
Falconer, D. S. 1965. The inheritance of liability to certain diseases estimated from the incidence among relatives. Ann. Hum. Genet. 29: 51–76.CrossRefGoogle Scholar
Land, R. B. 1971. The incidence of oestrus during lactation in Finnish Landrace, Dorset Horn and Finn-Dorset sheep. J. Reprod. Fert. 24: 345–352.CrossRefGoogle ScholarPubMed
Land, R. B. 1973. The expression of female sex limited characters in the male. Nature, Lond. 241: 208–209.CrossRefGoogle ScholarPubMed
Land, R. B., Pelletier, J., Thimonier, J. and Mauléon, P. 1973. Quantitative study of genetic differences in the incidence of oestrus, in ovulation and in the plasma concentration of luteinizing hormone in the sheep. J. Endocr. 58: 305–317.CrossRefGoogle ScholarPubMed
McGuirk, B. J. 1970. Hybrid vigour in sheep production. M.Sc. Thesis, University of New South Wales.Google Scholar
Mariana, J. C. 1970. Étude sur le nombre d'ovulations obtenues après injection de PMSG chez la vache: notion de seuil de réponse. Annls Biol. anim. Biochim. Biophys. 10: 575–579.CrossRefGoogle Scholar
Meyer, H. H. and Bradford, G. E. 1973. Reproduction in Targhee and Finnish Landrace × Targhee ewes. J. Anim. Sci. 36: 847–853.CrossRefGoogle ScholarPubMed
Roberts, R. C. 1965. Some contributions of the laboratory mouse to animal breeding research. Part II. Genetic analysis of litter size and fertility in the mouse. Anim. Breed. Abstr. 33: 515–526.Google Scholar
Russell, W. S. 1973. Compreg Users' Guide, IU/RC Report No. 19.250.118, Program Library Unit, Edinburgh Regional Computing Centre.Google Scholar
Sidwell, G. M., Everson, D. O. and Terrill, C. E. 1962. Fertility, prolificacy and Iamb viability of some pure breeds and their crosses. J. Anim. Sci. 21: 875–879.CrossRefGoogle Scholar
Turner, H. N. 1969. Genetic improvement of reproductive rate in sheep. Anim. Breed. Abstr. 37: 545–563.Google Scholar