Hostname: page-component-848d4c4894-nr4z6 Total loading time: 0 Render date: 2024-04-30T13:12:07.423Z Has data issue: false hasContentIssue false
  • English
  • Français

Effects of live weight and energy intake on nitrogen balance and total N requirements of lambs

Published online by Cambridge University Press:  25 March 2008

J. L. Black  and
D. A. Griffiths
J. L. Black
Affiliation:
CSIRO, Division of Animal Physiology, Ian Clunies Ross Animal Research Laboratory, Prospect, POBox 239, Blacktown, New South Wales 2148, Australia
D. A. Griffiths
Affiliation:
CSIRO, Division of Mathematical Statistics, Newtown, New South Wales 2042, Australia
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

1. Results of 298 nitrogen balance studies from experiments with male cross-bred lambs, ranging in weight from 3 to 38 kg, which had been either fasted, or fed entirely on liquid diets of varying protein content at various energy intakes up to ad lib. intake, were used to quantitatively describe the effects of the amount and quality of absorbed protein, energy intake and live weight on N balance and total N requirement of lambs.

2. When N intake was less than the amount required, N balance was independent of energy intake, but linearly related to absorbed N and metabolic body-weight (live weight0·75). In the fitted relationship, the coefficient of absorbed N was shown to be an estimate of the biological value of absorbed protein and the coefficient of metabolic body-weight was an estimate of the loss of endogenous N in both urine and faeces. For the milk-based diets used in the experiment biological value was 0·72 and the total endogenous N loss in urine and faeces was 148 mg N/kg0·75 per d.

3. When N intake was in excess of the amount required, N balance in lambs of a constant live weight increased linearly with metabolizable energy (ME) intake, at a rate that decreased with increasing live weight. Similarly at constant ME intake, N balance was a curvilinear decreasing function of metabolic body-weight. When N balance was expressed per unit metabolic body-weight, it was constant for lambs of all weights when ME intake was about 0·23 MJ/kg0·75 per d, but it decreased linearly with increasing metabolic body-weight for ME intakes above this level.

4. N balance of fasted lambs was several times less than predicted by either of the relationships established for fed animals, and was found to be linearly related to metabolic body-weight.

5. The effects of energy intake and live weight on the total N requirement of lambs were determined. When total N requirement was expressed per unit of energy intake, it was found to be constant at 0·9 g N/MJ ME for all lambs irrespective of live weight when ME intake was 0·23 MJ/kg0·7 per d. However, as ME intake/unit metabolic body-weight was raised above this level, N requirement/unit ME intake increased for lambs weighing less than c. 23 kg, but decreased for heavier animals.

Type
General Nutrition
Information
British Journal of Nutrition , Volume 33 , Issue 3 , May 1975 , pp. 399 - 413
Copyright
Copyright © The Nutrition Society 1975

References

Agricultural Research Council (1965). The Nutrient Requirements of Livestock No. 2, Ruminants. London: Agricultural Research Council.Google Scholar
Agricultural Research Council (1967). The Nutrient Requirements of Livestock No. 3, Pigs. London: Agricultural Research Council.Google Scholar
Allison, J. B., Anderson, J. A. & Seeley, R. D. (1947). J. Nutr. 33, 361.CrossRefGoogle Scholar
Andrews, R. P. & Ørskov, E. R. (1970). J. agric. Sci., Camb. 75, 11.CrossRefGoogle Scholar
Balch, C. C. (1967). Wld Rev. Anim. Prod. 14, 84.Google Scholar
Black, J. L. (1974). Proc. Aust. Soc. Anim. Prod. 10, 211.Google Scholar
Black, J. L., Pearce, G. R. & Tribe, D. E. (1973). Br. J. Nutr. 30, 45.CrossRefGoogle Scholar
Blaxter, K. L. (1962). The Energy Metabolism of Ruminants. London: Hutchinson Scientific and Technical.Google Scholar
Blaxter, K. L. & Mitchell, H. H. (1948). J. Anim. Sci. 7, 351.CrossRefGoogle Scholar
Blaxter, K. L. & Wood, W. A. (1952). Br. J. Nutr. 6, 1.CrossRefGoogle Scholar
Brody, S. (1945). Bioenergetics and Growth. New York: Reinhold.Google Scholar
Chudy, A. & Schiemann, R. (1969). Publs Eur. Ass. Anim. Prod. no. 12, p. 161.Google Scholar
Cornish, E. A. (1950). Aust. J. Sci. Res. B3, 178.Google Scholar
Graham, N. McC. & Searle, T. W. (1972). Aust. J. agric. Res. 23, 97.CrossRefGoogle Scholar
Graham, N. McC., Searle, T. W. & Griffiths, D. A. (1974). Aust. J. agric. Res. 25, 957.CrossRefGoogle Scholar
Hegsted, D. M. & Neff, R. (1970). J. Nutr. 100, 1173.CrossRefGoogle Scholar
Hodge, R. W. (1971). Nutritional studies with the young ruminant. PhD Thesis, University of Melbourne.Google Scholar
Kleiber, M. (1969). Publs Eur. Ass. Anim. Prod. no. 12, p. 505.Google Scholar
Markowitz, J., Archibald, J. & Downie, H. G. (1964). Experimental Surgery 5th ed. Baltimore: Williams and Wilkins.Google Scholar
Miller, D. S. & Payne, P. R. (1963). J. theoret. Biol. 5, 398.CrossRefGoogle Scholar
Munro, H. N. (1964). In Mammalian Protein Metabolism Vol. 1, p. 381 [Munro, H. N. and Allison, J. B., editors]London and New York: Academic Press.CrossRefGoogle Scholar
Munro, H. N. & Naismith, D. J. (1953). Biochem. J. 54, 191.CrossRefGoogle Scholar
Norton, B. W. (1968). The nutrition of the milk-fed lamb: N retention during growth. PhD Thesis, University of Sydney.Google Scholar
Norton, B. W. & Walker, D. M. (1971 a). Br. J. Nutr. 26, 1.CrossRefGoogle Scholar
Norton, B. W. & Walker, D. M. (1971 b). Br. J. Nutr. 26, 7.CrossRefGoogle Scholar
Ørskov, E. R. (1970). In Nutrition Conference for Feed Munufacturers p. 20 [Swan, H. and Lewis, D., editors]London: J. & A. Churchill.Google Scholar
Preston, R. L. (1966). J. Nutr. 90, 157.CrossRefGoogle Scholar
Walker, D. M. (1967). Br. J. Nutr. 21, 289.CrossRefGoogle Scholar
Walker, D. M. & Cook, L. J. (1967). Br. J. Nutr. 21, 237.CrossRefGoogle Scholar
Walker, D. M., Cook, L. J. & Jagusch, K. T. (1967). Br. J. Nutr. 21, 275.CrossRefGoogle Scholar
Walker, D. M. & Norton, B. W. (1971 a). Br. J. Nutr. 26, 15.CrossRefGoogle Scholar
Walker, D. M. & Norton, B. W. (1971 b). J. agric. Sci., Camb. 77, 363.CrossRefGoogle Scholar