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In vivo estimation of carcass meat by ultrasound in ram lambs slaughtered at an average live weight of 37 kg

Published online by Cambridge University Press:  02 September 2010

A. Fortin
Affiliation:
Animal Research Centre, Agriculture Canada, Ottawa, Ontario, Canada, K1A OC6
J. N. B. Shrestha
Affiliation:
Animal Research Centre, Agriculture Canada, Ottawa, Ontario, Canada, K1A OC6
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Abstract

Ultrasonic measurements of fat thickness and m. longissimus depth 25 and 50 mm lateral to the mid line at the last rib and 100 mm caudally to the last rib were made, before slaughter, on 273 ram lambs using two probes: the Scanogram and Krautkramer. The lambs were from three strains: a meat-type sire strain and two fecund dam strains. They weighed on average 37·3 kg at scanning, (range 29·0 to 51·3 kg), well within the weight range over which Canada Al-grade lambs are marketed in Canada. Their carcasses contained on average 437 g trimmed boneless meat per kg (s.d. pooled within strain = 24·1 g/kg).

The precision with which the ultrasonic measurements combined with live weight at scanning predicted trimmed boneless meat (weight and proportion) was examined. Fat thickness measurements had no predictive value (P > 0·05). The residual standard deviations for the prediction of trimmed boneless meat in the half carcass (weight and proportion) from weight at scanning were 0·29 kg and 21·5 kg, respectively; the addition of the m. longissimus depth measurement reduced the residual standard deviations by 0·02 kg and 1·1 g/kg, respectively. The weight of trimmed boneless meat was predicted with more precision than the proportion of trimmed boneless meat. Strain, location of measurement site or type of instrument did not change the precision of prediction.

It is concluded that prediction of trimmed boneless meat in young ram lambs based on live animal ultrasonic measurements made with the Scanogram or Krautkramer lacks the level of precision necessary for practical application.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1986

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References

REFERENCES

Barr, A. J., Goodnight, J. J., Sall, J. P. and Helwig, J. T. 1976. SAS User's Guide. Statistical Analysis System Institute, Raleigh, NC.Google Scholar
Bass, J. J., Woods, E. G. and Paulsen, W. D. 1982. A comparison of three ultrasonic machines (Danscan, AIDD (NZ) and Body Composition Meter) and subjective fat and conformation scores for predicting chemical composition of live sheep. Journal of Agricultural Science, Cambridge 99: 529532.CrossRefGoogle Scholar
Botkin, M. P., Field, R. A., Riley, M. L., Nolan, J. C. Jr and Roehrkasse, G. P. 1969. Heritability of carcass traits in lambs. Journal of Animal Science 29: 251255.CrossRefGoogle Scholar
Clements, B. W., Thompson, J. M., Harris, D. C. and Lane, J. G. 1981. Prediction of carcase fat depth in live lambs: A comparison of techniques. Australian Journal of Experimental Agriculture and Animal Husbandry 21: 566569.CrossRefGoogle Scholar
Cuthbertson, A., Croston, D. and Jones, D. W. 1984. In vivo estimation of lamb carcass composition and lean tissue growth rate. In In vivo Measurement of Body Composition in Meat Animals (ed. Lister, D.), pp. 163166. Elsevier, New York.Google Scholar
Fortin, A. 1980. Fat thickness measured with three ultrasonic instruments on live ram lambs as predictors of cutability. Canadian Journal of Animal Science 60: 857867.CrossRefGoogle Scholar
Hocking, R. K. 1976. The analysis and selection of variables in linear regression. Biometrics 32: 149.CrossRefGoogle Scholar
Jones, S. D. M., Walton, J. S., Wilton, J. W. and Szkotnicki, J. E. 1982. The use of urea dilution and ultrasonic backfat thickness to predict the carcass composition of live lambs and cattle. Canadian Journal of Animal Science 62: 371379.CrossRefGoogle Scholar
Kempster, A. J. 1983. Carcass quality and its measurement in sheep. In Sheep Production (ed. Haresign, W.), pp. 5974. Butterworths, London.Google Scholar
Kempster, A. J., Arnall, D., Alliston, J. C. and Barker, J. D. 1982. An evaluation of two ultrasonic machines (Scanogram and Danscanner) for predicting the body composition of live sheep. Animal Production 34: 249255.Google Scholar
Kempster, A. J., Cuthbertson, A., Jones, D. W. and Owen, M. G. 1981. Predition of body composition of live cattle using two ultrasonic machines of differing complexity: a report of four separate trials. Journal of Agricultural Science, Cambridge 96: 301307.CrossRefGoogle Scholar
Pattie, W. A., Thompson, J. M. and Butterfield, R. M. 1975. An Evaluation of the Scanogram as an Ultrasonic Aid for Assessing Carcase Composition in Live Sheep. A report submitted to the Australian Meat Board.Google Scholar
Shelton, M., Smith, G. C. and Orts, F. 1977. Predicting carcass cutability of Rambouillet rams using live animal tracts. Journal of Animal Science 44: 333337.CrossRefGoogle Scholar
Stouffer, J.R. and Westervelt, R. G. 1977. A review of ultrasonic applications in animal science. Journal of Clinical Ultrasound 45: 124127.CrossRefGoogle Scholar
Wolf, B. T., Smith, C., King, J. W. B. and Nicholson, D. 1981. Genetic parameters of growth and carcass composition in crossbred lambs. Animal Production 32: 17.Google Scholar