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Crossbred sheep production. III. Selection for growth rate and carcass attributes in the second-cross lamb

Published online by Cambridge University Press:  02 September 2010

Maurice Bichard
Affiliation:
School of Agriculture, University of Newcastle-upon-Tyne
B. C. Yalçin
Affiliation:
School of Agriculture, University of Newcastle-upon-Tyne
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Extract

Results have been presented from a small scale investigation into operational and theoretical aspects of progeny testing Down rams as sires of crossbred fat lambs. Twenty-six Suffolk rams were evaluated from the growth records of 922 lambs out of Border Leicester × Cheviot ewes. In addition measurements were recorded on 260 carcasses. Significant differences were found between corrected progeny means, which were equivalent t o heritabilities of between 0·03 and 0·13 for live-weights up to 15 weeks, and o t higher values for skeletal measurements.

A scheme for the selection of Down rams was considered which involved measuring the individual performance of all ram lambs and then progeny testing the best of these by measuring a fixed total number of crossbred lambs. It was concluded that the proportion to be progeny tested could be varied within quite wide limits without seriously changing the genetic merit of the selected group.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1964

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References

REFERENCES

Barton, R. A., Phillips, T. O. & Clarke, E. A., 1949. Influence of sire on fat lamb quality. Proc. N.Z. Soc. Artim. Prod., 1949, p. 66.Google Scholar
Blackwell, R. L. & Henderson, C. R., 1955. Variation in fleece weight, weaning weight and birth weight of sheep under farm conditions. J. Anim. Sci., 14: 831.CrossRefGoogle Scholar
Bowman, J. C., 1959. Selection for heterosis. Anim. Breed. Abstr., 27: 261.Google Scholar
Broadbent, J. S., 1963. Relationship of performance to progeny testing of fat lamb sires. Anim. Prod., 5: 218 (Abstr.).Google Scholar
Butcher, R. L., Dunbar, R. S. & Welch, J. A., 1959. Genetic parameters of birth and 140-day weights in purebred lambs. J. Anim. Sci., 18: 1462 (Abstr.).Google Scholar
Bywater, T. L., 1945. Sheep for long leys. Proc. Brit. Soc. Anim. Prod., 1944, p. 25.CrossRefGoogle Scholar
Dickerson, G. E. & Hazel, L. N., 1944. Effectiveness of selection on progeny performance as a supplement to earlier culling in livestock. J. agric. Res., 69: 459.Google Scholar
Dickson, G. R., 1959. The more efficient grazing of ewes and lambs. J. Brit. Grass. Soc., 14: 172.CrossRefGoogle Scholar
Donald, H. P., 1958. Crossbred lamb production from cast-for-age Blackface ewes. Proc. Brit. Soc. Anim. Prod., 1958, p. 77.CrossRefGoogle Scholar
Falconer, D. S., 1960. Introduction to quantitative genetics. Oliver and Boyd, Edinburgh.Google Scholar
Felts, V. L., Chapman, A. B. & Pope, A. L., 1957. Estimates of genetic and phenotypic parameters for use in a farm flock ewe selection index. J. Anim. Sci., 16: 1048.Google Scholar
Fisher, R. A., 1941. Statistical methodsfor research workers. Oliver and Boyd, Edinburgh. 8th ed.Google Scholar
Givens, C. S. Jr, Carter, R. C. & Gaines, J. A., 1960. Selection indices for weanling traits in spring lambs. J. Anim. Sci., 19: 134.CrossRefGoogle Scholar
Harrington, R. B., Brothers, D. G. & Whiteman, J. V., 1962. Heritability of gain of lambs measured at different times and by different methods. J. Anim. Sci., 21: 78.CrossRefGoogle Scholar
Knapp, B. Jr & Clark, R. T., 1950. Revised estimates of heritability of economic characteristics in beef cattle. J. Anim. Sci., 9: 582.CrossRefGoogle ScholarPubMed
McLean, J. W., 1948. Progeny testing in sheep. The inheritance of birth weight, growth rate and cannon bone length. Proc. N.Z. Soc. Anim. Prod., 1948, p. 86.Google Scholar
Pálsson, H., 1939. Meat qualities in the sheep with special reference to Scottish breeds and crosses. I. J. agric. Sci., 29: 544.CrossRefGoogle Scholar
Purser, A. F., 1956. The use of correction for regression on a second character to increase the efficiency of selection. In Biometrical Genetics. Edited by Kempthorne, O., Per-gamom Press.Google Scholar
Rae, A. L., 1952. Crossbreeding of sheep. II. Crossbreeding for lamb and mutton production. Anim. Breed. Abstr., 20: 287.Google Scholar
Rendel, J., 1956. Heritability of multiple birth in sheep. J. Anim. Sci., 15: 193.CrossRefGoogle Scholar
Robertson, A., 1957. Optimum group size in progeny testing and family selection. Biometrics., 13: 442.CrossRefGoogle Scholar
Robertson, A. & Rendel, J. M., 1950. The use of progeny testing with artificial insemination in dairy cattle. J. Genet., 50: 21.CrossRefGoogle ScholarPubMed
Smith, C., Kino, J. W. B. & Gilbert, N., 1962. Genetic parameters of British Large White bacon pigs. Anim. Prod., 4: 128.Google Scholar
Taneja, G. C., 1959. Sources of variation in mutton score and body measurements in Australian Merino sheep. Indian J. Vet. Sci. Anim. Husb., 29: 87.Google Scholar
Wiener, G., 1961. Population dynamics in fourteen lowland breeds of sheep in Great Britain. J. agric. Sci., 57: 21.CrossRefGoogle Scholar
Yalcin, B. C. & Bichard, M., 1964a. Crossbred sheep production. I. Factors affecting production from the crossbred ewe flock. Anim. Prod., 6: 73.Google Scholar
Yalcin, B. C. & Bichard, M., 1964b. Crossbred sheep production. II. The repeatability of performance and the scope for culling. Anim. Prod., 6: 85.Google Scholar