Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-25T08:14:31.523Z Has data issue: false hasContentIssue false
  • English
  • Français

Body composition of young sheep: II. Effect of stocking rate on body composition of Dorset Horn cross lambs

Published online by Cambridge University Press:  27 March 2009

G. W. Arnold ,
H. R. Gharaybeh ,
M. L. Dudzinski ,
W. R. McManus  and
A. Axelsen
Get access Rights & Permissions [Opens in a new window]

Summary

Empty body weight and body measurements were made on 142 lambs from Border Leicester × Merino and Merino ewes mated to Dorset Horn rams, grazed at three stocking rates and slaughtered at approximately 32·3 kg full body weight (FBW). Carcass composition studies were made on 58 of these lambs. An approximate doubling of growth rate during the first 6 weeks of life occurred between stocking rates for lambs from Merino ewes. A smaller difference was found in lambs from Border Leicester × Merino ewes. Growth rates of lambs from Merinos were significantly lower at all times from birth to slaughter. Stocking rate, breed and sex effects on growth rate resulted in lambs reaching mean weight of 32·3 kg at 80–150 days.

A three-way analysis of variance was performed on data for all parameters measured using FBW as a covariate. These parameters were of carcass measurements and composition, and of composition of the internal organs. There were no effects of stocking rate on empty body weight, carcass weight, or any carcass measurements. The weight of dry edible meat was depressed at the high stocking rate due to a higher moisture content. The fresh weight of internal organs was lower at the high stocking rate. A number of sex differences were found. Ewes had lighter carcasses and heavier cannon bones; their edible meat had a higher moisture content and higher ash content than wethers. Eye muscle width was less in ewes than in wethers. Internal organs of ewes had a lower EE % and higher CP % than those of wethers. The only breed type differences were in the weights of internal organs and eye muscle widths at the 9–10th and lOth–llth ribs, and age to slaughter.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 72 , Issue 1 , January 1969 , pp. 77 - 84
Copyright
Copyright © Cambridge University Press 1969

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

Arnold, G. W. & Bush, I. G. (1962). The effects of stocking rate and grazing management on fat lamb production. Proc. Aust. Soc. Anim. Prod. 4, 121–9.Google Scholar
Arnold, G. W., Mcmanus, W. R. & Bush, I. G. (1964). Studies in the wool production of grazing sheep. I. Seasonal variation in feed intake, liveweight and wool production. Aust. J. exp. Agric. Anim. Husb. 4, 392–403.CrossRefGoogle Scholar
Arnold, G. W., Mcmanus, W. R. & Dudzinski, M. L. (1965). Studies in the wool production of grazing sheep. 3. Changes in efficiency of production. Aust. J. exp. Agric. Anim. Husb. 5, 396–403.CrossRefGoogle Scholar
Davies, H. L. (1963). The milk production of Merino ewes at pasture. Aust. J. agric. Res. 14, 824–38.Google Scholar
Elsley, F. W. A., Mcdonald, I. & Fowler, V. R. (1964). The effect of plane of nutrition on the carcasses of pigs and lambs when variations in fat content are excluded. Anim. Prod. 6, 141–54.Google Scholar
Gharaybeh, H. R., Arnold, G. W., McManus, W. R. & Dudzinski, M. L. (1966). Prediction of body composition in live animals. Proc. Aust. Soc. Anim. Prod. 6, 284–90.Google Scholar
Gharaybeh, H. R., McManus, W. R., Arnold, G. W. & Dudzinski, M. L. (1968). Body composition of young sheep. I. Body composition in Merino and Border Leicester x Merino hoggets in relation to and at common empty body weight. J. agric. Sci., Camb. 72, 65–75.CrossRefGoogle Scholar
Lambourne, L. J. & Reardon, T. F. (1963). Effect of environment on the maintenance requirements of Merino wethers. Aust. J. agric. Res. 14, 272–92.CrossRefGoogle Scholar
Palsson, H. (1939). Meat qualities in the sheep with special reference to Scottish breeds and crosses. I. Carcase measurements and ‘sample joints’ as indices of quality and composition. J. agric. Sci., Camb. 29, 544–626.CrossRefGoogle Scholar