Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-27T21:49:38.210Z Has data issue: false hasContentIssue false

An economic selection index for lean meat production in New Zealand sheep

Published online by Cambridge University Press:  02 September 2010

G. Simm
Affiliation:
Animal Sciences Group, Lincoln College, Canterbury, New Zealand
M. J. Young
Affiliation:
Animal Sciences Group, Lincoln College, Canterbury, New Zealand
P. R. Beatson
Affiliation:
Animal Sciences Group, Lincoln College, Canterbury, New Zealand
Get access

Abstract

An economic selection index was derived for terminal sire sheep breeds or strains, using physical and financial results from New Zealand export lamb-producing flocks. The aggregate breeding value of the index comprised carcass lean weight and carcass total fat weight. Index measurements were live weight, ultrasonic fat depth and ultrasonic muscle depth. Economic values used for lean and fat weights (NZ$5·65 and NZ$–1·2 per kg, respectively) were the change in profit per kg increase in lean or fat weight from that in the average carcass of lambs slaughtered in 1984/85. The s.d. of the aggregate breeding value was NZS3·20, and the correlation between the full index and the aggregate breeding value was 0·23. This correlation fell to 0·18, 0·15 and 0·07, respectively, when muscle depth or fat depth or muscle and fat depths were omitted from the index. Selection on the full index, or on the index omitting muscle depth was expected to lead to an increase in carcass lean weight and a slight decrease in carcass fat weight. Selection on the index omitting fat depth, or selection on live weight alone, was expected to lead to an increase in both fat and lean weights.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1987

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Agricultural Research Council. 1980. The Nutrient Requirements of Ruminant Livestock. Commonwealth Agricultural Bureaux, Slough.Google Scholar
Bennett, G. L., Johnson, D. L., Kirton, A. H. and Carter, A. H. 1982. Genetic variation of Southdown lamb carcass traits. Annual Report, Genetics Section, Ruakura Animal Research Station, pp. 2526.Google Scholar
Bennett, G. L., Meyer, H. H., Bass, J. J., Clarke, J. N. and Rae, A. L. 1983. Estimates of genetic and phenotypic (co)variances for measurements directly or indirectly related to DSIR probe. Summaries of Papers given at Overfatnessl Lean Meal Workshop, Lincoln College, pp. 1112 (Abstr.).Google Scholar
Botkin, M. P., Field, R. A., Riley, M. L., Nolan, J. C. and Roehrkasse, G. P. 1969. Heritability of carcass traits in lambs. Journal of Animal Science 29: 251255.CrossRefGoogle Scholar
Buxton, D. 1985. Profitable Lamb Production. Waitaki N.Z.R. Ltd, Christchurch, NZ.Google Scholar
Cunningham, E. P. 1970. Selind: a Fortran computer program for genetic selection indexes. An Foras Taluntais, Dunsinea, Eire (Mimeograph).Google Scholar
Dwyer, K. M. 1985. Environmental and genetic sources of variation for hogget production traits of Border Leicester, Corriedale and Dorset Down sheep. B.Agric.Sci. Dissertation, University of Canterbury, NZ.Google Scholar
Fennessy, P. F., Greer, G. J. and Bass, J. J. 1982. Progeny test of selected lean and fat rams. Proceedings of the New Zealand Society of Animal Production 42: 137140.Google Scholar
Fowler, V. R., Bichard, M. and Pease, A. 1976. Objectives in pig breeding, Animal Production 23: 365387.Google Scholar
Kirton, A. H., Carter, A. H., Clarke, J. N. and Duganzich, D. M. 1984a. Dressing percentages of lambs. Proceedings of the New Zealand Society of Animal Production 44: 231233.Google Scholar
Kirton, A. H., Duganzich, D. M., Feist, C. L., Bennett, G. L. and Woods, E. G. 1985. Prediction of lamb carcass composition from GR and carcass weight. Proceedings of the New Zealand Society of Animal Production 45: 6365.Google Scholar
Kirton, A. H. and Johnson, D. L. 1979. Interrelationships between GR and other lamb carcass fatness measurements. Proceedings of the New Zealand Society of Animal Production 39: 194201.Google Scholar
Kirton, A. H., Woods, E. G. and Duganzich, D. M. 1984b. Predicting the fatness of lamb carcasses from carcass wall thickness measured by ruler or by a total depth indicator (TDI) probe. Livestock Production Science 11: 185194.CrossRefGoogle Scholar
McEwan, J. C., Fennessy, P. F., Clarke, J. N., Hickfy, S. M. and Knowler, M. A. 1984. Selection for productive traits on back fat depth in ewe lambs. Proceedings of the New Zealand Society of Animal Production 44: 249252.Google Scholar
NEW Zealand Meat Producers' Board. 1985. Annual Report. Wellington, N.Z.Google Scholar
New Zealand Meat and wool Boards' Economic Service. 1982. Sheep and beef farm survey, 1980-81. Publication No. 1871.Google Scholar
New Zealand Meal and Wool Boards' Economic Service. 1983a. Supplement to the sheep and beef farm survey. 1980-81. Publication No. 1873.Google Scholar
New Zealand Meat and Wool Boards' Economic Service. 1983b. Sheep and beef farm survey. 1981-82. Publication No. 1890.Google Scholar
New Zealand Meat and Wool Boards' Economic Service. 1984a. Supplement to the sheep and beef farm survey, 1981-82. Publication No. 1893.Google Scholar
New Zealand Meat and Wool Boards' Economic Service. 1984b. Sheep and beef farm survey, 1982-83. Publication No. 1908.Google Scholar
New Zealand Meat and Wool Boards' Economic Service. 1985. Supplement to the sheep and beef farm survey, 1982-83. Publication No. 1911.Google Scholar
Nicol, A. M. and Parratt, A. C. 1984. Methods of ranking two-tooth rains for fat-free carcass growth rate. Proceedings of the New Zealand Society of Animal Production 44: 253256.Google Scholar
Parratt, A. C. and Simm, G. 1987. Selection indices to improve lean meat production from sheep in the United Kingdom. Animal Production 45: 8796.Google Scholar
Purchas, R. W., Bennett, G. L. and Dodd, C. J. 1985. The calculation of a simple lean-growth index for young sheep. Proceedings of the New Zealand Society of Animal Production 45: 7376.Google Scholar
Rah, A. L. 1984. Development of selection programs for increasing lean meat production in sheep. Proceedings of 4th Conference of the Australian Association of Animal Breeding and Genetics, pp. 37.Google Scholar
Rattray, P. V. 1986. Feed requirements for maintenance, gain and production. In Sheep Production, Vol. 2. Nutrition. New Zealand Institute of Agricultural Science, Wellington. In press.Google Scholar
Rattray, P. V., Garrett, W. N., Hinman, N., East, N.E. and Meyer, H. H. 1973. Relationships between carcass density and body composition with observations on differences in the fat free body composition in sheep. Journal of Animal Science 37: 13321338.CrossRefGoogle Scholar
Sehested, E. 1984. Evaluation of carcass composition of live lambs based on computed tomogtsphy. Proceedingss of the European Association of Animal Production, Paper G5.21 (Abstr.).Google Scholar
Simm, G., Smith, C. and Prescott, J. H. D. 1986. Selection indices to improve the efficiency of lean meat production in cattle. Animal Production 42: 183193.Google Scholar
Simm, G., Smith, C. and Thompson, R. 1987. The use of product traits such as lean growth rate as selection criteria in animal breeding. Animal Production 45: 307316.Google Scholar
Smith, C. 1978. The effect of inflation and form of investment on the estimated value of genetic improvement in farm livestock. Animal Production 26: 101110.Google Scholar
Smith, C. 1983. Effects of changes in economic weights on the efficiency of index selection. Journal of Animal Science 56: 10571064.CrossRefGoogle Scholar
Sykes, A. R. and Nicol, A. M. 1983. The energy requirements of the weaned lamb. In Lamb Growth Technical Handbook, pp. 121134. Lincoln College, Canterbury, NZ.Google Scholar
Vandepitte, W. M. and Hazel, L. N. 1977. The effect of errors in the economic weights on the accuracy of selection indices. Annales de Gènèlique et de Sèlection Animale 9: 87103.Google Scholar