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Meat properties of lambs grown to 32 kg at various rates on phalaris or lucerne pastures and an apparent effect of pre-slaughter ambient temperature

Published online by Cambridge University Press:  27 March 2009

E. P. Furnival
Affiliation:
G.S.I.R.O. Division of Animal Production, Pastoral Research Laboratory, Armidale, New South Wales, 2350, Australia
J. L. Corbett
Affiliation:
G.S.I.R.O. Division of Animal Production, Pastoral Research Laboratory, Armidale, New South Wales, 2350, Australia
W. R. Shorthose
Affiliation:
C.S.I.R.O. Division of Food Research, Meat Research Laboratory, P.O. Box 12, Cannon Hill, Queensland, 4170, Australia

Summary

One hundred and fifty-nine Corriedale x Dorset Horn lambs were slaughtered at 32 kg live weight at ages varying from 98 to 303 days. The youngest lambs were from ewes on a pasture with high herbage availability and had not been weaned; the next youngest were from the same group of ewes but had been weaned at 6 or 12 weeks of age. Older lambs had been weaned at 6, 12 or 29 weeks from ewes on a pasture with low herbage availability. The weaned lambs grazed either a phalaris or a lucerne pasture.

Lambs that grazed lucerne had a greater dressing percentage and a heavier carcass. Over all lambs, ultimate pH of the m. semimenxbranosus ranged from 5·4 to 6·0 and Warner-Bratzler shear values increased twofold from lowest to highest pH. Minimum ambient temperatures during the nights before the slaughter days ranged from 13 to – 1°C; ultimate pH increased by 0·25 units with decreasing temperature over the range, equivalent to an increase in shear value of 26%. Shear values adjusted for pH differences increased from about 3·4 kg/cm2 at 130 days of age to about 7·5 kg/cm2 at 300 days.

Visual attractiveness of 13th rib chops increased with increasing area of the m. longissimus dorsi. Attractiveness was least at intermediate dominant wavelength (redness) of this muscle, but was not related to its reflectance. Optimum fat depth was about 2·4 mm. In general, chops from younger lambs were more attractive than those from older lambs.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1977

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References

Anon. (19731974). Meat Research Institute, Bristol. Annual Report, p. 42.Google Scholar
Batcher, O. M., Dawson, E. H., Pointer, M. T. & Gilpin, G. L. (1962). Quality of raw and cooked lamb meat as related to fatness and age of animal. Food Technology, 16 102–10.Google Scholar
Blaxter, K. L. (1962). The Energy Metabolism of Ruminants. London: Hutchinson.Google Scholar
Bouton, P. E., Harris, P. V. & Shorthose, W. R. (1971). Effect of ultimate pH upon the water-holding capacity and tenderness of mutton. Journal of Food Science 36, 453–9.CrossRefGoogle Scholar
Burton, J. H. & Reid, J. T. (1969). Interrelationships among energy input, body size, age and body composition of sheep. Journal of Nutrition 97, 517–24.CrossRefGoogle ScholarPubMed
Corbett, J. L., Furnival, E. P., Southcott, W. H., Park, R. J. & Shorthose, W. R. (1973). Induced cryptorchidism in lambs. Effect on growth rate, carcass and meat characteristics. Animal Production 16, 157–63.Google Scholar
Furnival, E. P. & Corbett, J. L. (1976). Early weaning of grazing sheep. 1. Growth of lambs. Australian Journal of Experimental Agriculture and Animal Husbandry 16, 149–55.CrossRefGoogle Scholar
Hall, J. L., Latschar, C. E. & Mackintosh, D. L. (1944). Quality of beef. IV. Characteristics of dark cutting beef. Survey and preliminary investigation. Kansas Agricultural Experimental Station Technical Bulletin 58.Google Scholar
Jagusch, K. T. & Nicol, A. M. (1970). Pasture type and lamb carcass composition: a comparison of experimental design. Proceedings of the New Zealand Society of Animal Production 30, 116–22.Google Scholar
Ledward, D. A. & Shorthose, W. R. (1971). A note on the haem pigment concentration of lamb as influenced by age and sex. Animal Production 13, 193–5.Google Scholar
Lawrie, R. A. (1966). Meat Science. Oxford: Pergamon Press.Google Scholar
Munns, W. O. & Burrell, D. E. (1966). The incidence of dark-cutting beef. Food technology 20, 1601–3.Google Scholar
Nicol, A. M. & McLean, J. W. (1970). The influence of pasture species and exogenous oestrogen treatment on the liveweight gain and carcass composition of lambs. New Zealand Journal of Agricultural Research 13, 385–94.CrossRefGoogle Scholar
Preston, T. R. & Willis, M. B. (1970). Intensive Beef Production. Oxford: Pergamon Press.Google Scholar
Reed, K. F. M. (1972). Plants for Sheep in Australia (ed. Leigh, J. H. & Noble, J. C.), p. 193. Sydney, Australia: Angus & Robertson.Google Scholar
Searle, T. W., Graham, N. McC. & O'Callaghan, M. (1972). Growth in sheep. 1. The chemical composition of the body. Journal of Agricultural Science, Cambridge 79, 371–82.CrossRefGoogle Scholar
Winter, W. H. (1970). Effect of compensatory growth on meat quality in sheep. Proceedings of the Australian Society of Animal Production 8, 283–90.Google Scholar