Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-28T22:09:14.007Z Has data issue: false hasContentIssue false

Body composition studies with the milk-fed lamb. II. The effect of the age of the lamb and the protein content of the diet on the chemical composition of the body and its organs

Published online by Cambridge University Press:  27 March 2009

K. T. Jagusch
Affiliation:
Department of Animal Husbandry, University of Sydney, Australia, 2006
B. W. Norton
Affiliation:
Department of Animal Husbandry, University of Sydney, Australia, 2006
D. M. Walker
Affiliation:
Department of Animal Husbandry, University of Sydney, Australia, 2006

Summary

Eighteen male cross-bred lambs (aged 2–5 days) in two equal groups were given artificial milk diets of either low- or high-protein content; subgroups of three lambs were slaughtered after 2, 4 and 6 weeks on experiment. The composition of the change in empty body weight (E.B.W.), and the chemical composition of the change in weight of the separate compartments and organs, were determined by the comparative slaughter method.

Lambs given the high-protein diet made significant gains in weight and in all chemical components in all periods. The composition of their E.B.W. was closely related to E.B.W. regardless of age. Lambs given the low-protein diet made only small gains in weight in 6 weeks, of which 76% was fat. The chemical composition of their E.B.W. was closely related to E.B.W. within each age group. The net gain of protein of these lambs in 6 weeks represented only 1% of the total weight gain, and over 50% of the protein gain was in wool. The skin and blood lost protein during the first 2 weeks, and failed to recover this loss during the remaining 4 weeks. Other organs lost protein initially but recovered this loss between 2 and 6 weeks.

It was concluded that the initial loss of protein represented the labile protein reserves of the lamb, and the subsequent recovery was an adaptation to the low-protein diet. Furthermore, the results with both diets indicated that the skin and blood were the most inefficient of the organs in the body in utilizing the available N during a period of protein deficiency, or during a period of abundance in the dietary supply of N.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1970

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

Addis, T., Lee, D. D., Lew, W. & Poo, L. J. (1940). The protein content of the organs and tissues at different levels of protein consumption. J. Nutr. 19, 199205.Google Scholar
Garrow, J. S. (1959). The effect of protein depletion on the distribution of protein synthesis in the dog. J. clin. Invest. 38, 1241–50.Google Scholar
Hammond, J. (1932). Growth and Development of Mutton Qualities in Sheep. Edinburgh and London: Oliver and Boyd.Google Scholar
Jagusch, K. T., Norton, B. W. & Walker, D. M. (1970). Body composition studies with the milk-fed lamb. I. Chemical composition and calorific content of the body and organs of newly-born lambs. J. agric. Sci., Camb. 75, 273–7.CrossRefGoogle Scholar
Langlands, J. P. & Sutherland, H. A. M. (1969). An estimate of the nutrients utilized for live-weight gain by Merino sheep. Br. J. Nutr. 23, 603–9.Google Scholar
Ling, E. R., Kon, S. K. & Porter, J. W. G. (1961). The composition of milk and the nutritive value of its components. In Milk: the Mammary Gland and its Secretions (ed. Kon, S. K. and Cowie, A. T.), vol. II, p. 195. New York: Academic Press Inc.Google Scholar
Mitchell, H. H., Kammlade, W. G. & Hamilton, T. S. (1928). A technical study of the maintenance and fattening of lambs and their utilisation of a ration of alfalfa hay and corn. Bull. Ill. agric. Exp. Stn no. 314.Google Scholar
Norton, B. W. (1968). The nutrition of the milk-fed lamb: N retention during growth. Ph.D. thesis, University of Sydney.Google Scholar
Norton, B. W., Jagusch, K. T. & Walker, D. M. (1970). Body composition studies with the milk-fed lamb. III. The effect of the protein and energy intake on the composition of the live-weight gain. J. agric. Sci., Camb. 75, 287–92.CrossRefGoogle Scholar
Norton, B. W. & Walker, D. M. (1970). Nitrogen balance studies with the milk-fed lamb. 8. Labile protein reserves. Br. J. Nutr. (in the Press).Google Scholar
Pálsson, H. & Vergés, J. B. (1952a). Effects of the plane of nutrition on growth and the development of carcass quality in lambs. Part I. The effects of high and low planes of nutrition at different ages. J. agric. Sci., Camb. 42, 192.CrossRefGoogle Scholar
Pálsson, H. & Vergés, J. B. (1952b). Effects of the plane of nutrition on growth and the development of carcass quality in lambs. Part II. Effects on lambs of 30 lb carcass weight. J. agric. Sci., Camb. 42, 93149.Google Scholar
Steel, R. G. D. & Torrie, J. H. (1960). Principles and Procedures of Statistics. New York: McGraw-Hill Book Co. Inc.Google Scholar
Walker, D. M. & Cook, L. J. (1967). Nitrogen balance studies with the milk-fed lamb. 4. Effect of different nitrogen and sulphur intakes on live-weight gain and wool growth and on nitrogen and sulphur balances. Br. J. Nutr. 21, 237–56.Google Scholar
Walker, D. M. & Faichney, G. J. (1964). Nitrogen balance studies with the milk-fed lamb. 1. Endogenous urinary nitrogen, metabolic faecal nitrogen and basal heat production. Br. J. Nutr. 18, 187200.CrossRefGoogle ScholarPubMed
Wallace, L. R. (1948a). The growth of lambs before and after birth in relation to the level of nutrition. Parts II and III. J. agric. Sci., Camb. 38, 243302.CrossRefGoogle Scholar
Wallace, L. R. (1948b). The growth of lambs before and after birth in relation to the level of nutrition. Part III. J. agric. Sci., Camb. 38, 367401.Google Scholar
Weil, W. B. & Wallace, W. M. (1963). The effect of variable food intakes on growth and body composition. Ann. N.Y. Acad. Sci. 110, 358–73.CrossRefGoogle ScholarPubMed