Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-25T02:15:35.441Z Has data issue: false hasContentIssue false

Effects of long-term protein excess or deficiency on whole-body protein turnover in sheep nourished by intragastric infusion of nutrients

Published online by Cambridge University Press:  09 March 2007

S. M. Liu
Affiliation:
Rowett Research Institute, Greenburn Road, Bucksburn, Aberdeen AB2 9SB
G. E. Lobley
Affiliation:
Rowett Research Institute, Greenburn Road, Bucksburn, Aberdeen AB2 9SB
N. A. Macleod
Affiliation:
Rowett Research Institute, Greenburn Road, Bucksburn, Aberdeen AB2 9SB
D. J. Kyle
Affiliation:
Rowett Research Institute, Greenburn Road, Bucksburn, Aberdeen AB2 9SB
X.B. Chen
Affiliation:
Rowett Research Institute, Greenburn Road, Bucksburn, Aberdeen AB2 9SB
E.R. Ørskov
Affiliation:
Rowett Research Institute, Greenburn Road, Bucksburn, Aberdeen AB2 9SB
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.

The effect of long-term dietary protein excess and deficit on whole-body protein-N turnover (WBPNT) was examined in lambs nourished by intragastric infusions of nutrients. Ten sheep were given 500 mg N/kg metabolic weight (W0.75) per d from casein for 2 weeks and then either 50 (L), 500 (M) or 1500 (H) mg N/kgW0.75 per d for 6 weeks. Volatile fatty acids were infused at 500 kJ/kgW0.75 per d. Daily WBPNT was measured by continuous intravenous infusion of [l-13C]leucine 3 d before, and on days 2, 21 and 42 after the alteration in protein intake. Whole-body protein-N synthesis (WBPNS) was calculated as the difference between WBPNT and the protein-N losses as urinary NH3 and urea. Whole-body protein-N degradation (WBPNS) was then estimated from WBPNS minus protein gain determined from N balance. Fractional rates of WBPNS and WBPND were calculated against fleece-free body N content. WBPNS rates at the L, M and H intakes were respectively 35·1, 41·5 amd 6·37 g/d (P < 0.001) on average over the 6 weeks and WBPND rates were 39·5, 41·1 and 56·8 g/d (P < 0.001). The fractional rates of WBPNS were 5·01, 6·37 and 7·73% per d (P < 0.001) while those of WBPND were 5·64, 6·29 and 6·81% per d (P < 0.005) respectively. On days 2, 21 and 42, WBPNS rates at intake H were 54·0, 61·8 and 75·4 g/d (P = 0·03) respectively, and WBPND rates were 43·2, 56·4 and 70·9 g/d (P = 0.03); at intake L the amounts were 38·2, 34·2 and 32·8 g/d for WBPNS (P = 0.003) and for WBPND were 43·4, 38·0 and 36·9 g/d (P = 0·016) respectively. There were no significant (P > 0·05) differences in fractional rates of WBPNS and WBPND with time at either the L or H intake. We concluded that absolute protein turnover was affected both by dietary protein intake and by body condition while the fractional rate of turnover was predominantly influenced by intake.

Type
Protein intake and protein turnover in sheep
Copyright
Copyright © The Nutrition Society 1995

References

Agricultural Research Council (1984) The Nutrient Requirements of Ruminant Livestock, p. 49. Slough: Commonwealth Agricultural Bureaux.Google Scholar
Calder, A. G. & Smith, A. (1988) Stable isotope ratio analysis of leucine and ketoisocaproic acid in blood plasma by gas chromatography/mass spectrometry. Use of tertiary butyldimethylsilyl derivatives. Rapid Communications in Mass Spectrometry 2, 1416.CrossRefGoogle ScholarPubMed
Davidson, J., Mathieson, J. & Boyne, A. W. (1970) The use of automation in determining nitrogen by the Kjeldahl method, with final calculations by computer. Analyst 95, 181193.CrossRefGoogle ScholarPubMed
Davis, S. R., Barry, T. N. & Hughson, G. A. (1981) Protein synthesis in tissues of growing lambs. British Journal of Nutrition 44, 129140.Google Scholar
Fawcett, J. K. & Scott, J. E. (1960) Rapid and precise method for the determination of urea. Journal of Clinical Pathology 13, 156159.CrossRefGoogle ScholarPubMed
Fuller, M. F., Reeds, P. J., Cadenhead, A. & Seve, B. (1987) Effects of the amount of quality of dietary protein on nitrogen metabolism and protein turnover of pigs. British Journal of Nutrition 58, 287300.CrossRefGoogle ScholarPubMed
Garlick, P. J. (1980) Protein turnover in the whole animal and specific tissues. In Comprehensive Biochemistry - Protein Metabolism, Vol. 19B, pp. 77154 [Garlick, P.J. and Millward, D. J., editors]. Amsterdam: Elsevier.Google Scholar
Garlick, P. J., Graeme, A. C. & Waterlow, J. C. (1980) Influence of low-energy diets on whole-body protein turnover in obese subjects. American Journal of Physiology 238, E235E244.Google ScholarPubMed
Genstat 5. Release 2·2. (1988) Reference Manual. Rothamsted Experimental Station, Lawes Agricultural Trust. Oxford: Oxford Science Publications.Google Scholar
Hammond, A. G., Huntington, G. B., Reytnolds, P. J., Tyrrell, H. F. & Eisemann, J. H. (1987) Absorption, plasma flux and oxidation of L-leucine in heifers at two levels of intake. Journal of Animal Science 64, 420425.CrossRefGoogle ScholarPubMed
Harris, P. M. & Lobley, G. E. (1991) Amino acid and energy metabolism in the peripheral tissues of ruminants. In Physiological Aspects of Digestion and Metabolism in Ruminants: Proceedings of the Seventh International Symposium on Ruminant Physiology, pp. 201230 [Tsude, T., Sasaki, Y., Kawashima, R., editors]. San Diego: Academic Press.CrossRefGoogle Scholar
Harris, P. M., Skene, P. A., Buchan, V., Milne, E., Calder, A. G., Anderson, S. E., Connell, A. & Lobley, G. E. (1992) Effect of food intake on hind-limb and whole-body protein metabolism in young growing sheep: chronic studies based on arterio-venous techniques. British Journal of Nutrition 68, 389407.CrossRefGoogle ScholarPubMed
Lindsay, D. B. (1980) Amino acids as energy source. Proceedings of the Nutrition Society 39, 5359.CrossRefGoogle Scholar
Lobley, G. E. (1993) Protein metabolism and turnover. In Quantitative Aspects of Ruminant Digestion and Metabolism, pp. 313339 [Forbes, J.M. and France, J., editors]. London: C.A.B. International.Google Scholar
Lobley, G. E., Connell, A. & Buchan, V. (1987) Effect of food intake on protein and energy metabolism in finishing beef steers. British Journal of Nutrition 57, 457465.CrossRefGoogle ScholarPubMed
Lobley, G. E., Connell, A., Milne, E., Newman, A. M. & Ewing, T. A. (1994) Protein synthesis in splanchnic tissues of sheep offered two levels of intake. British Journal of Nutrition 71, 312.CrossRefGoogle ScholarPubMed
Lobley, G. E., Harris, P. M., Skene, P. A., Brown, D., Milne, E., Calder, A. G., Anderson, S. E., Garlick, P. J., Nevison, I. & Connell, A. (1992) Responses in tissue synthesis to sub- and supra-maintenance intake in young growing sheep: comparison of large-dose and continuous-infusion techniques. British Journal of Nutrition 68, 373388.CrossRefGoogle ScholarPubMed
MacLeod, N. A., Corrigall, W., Stirton, R. A. & Ørskov, E. R. (1982) Intragastric infusion of nutrients in cattle. British Journal of Nutrition 47, 547552.CrossRefGoogle ScholarPubMed
Marsh, W. H., Fingerhut, B. & Miller, H. (1965) Automated and manual direct methods for the determination of blood urea. Clinical Chemistry 11, 624627.CrossRefGoogle ScholarPubMed
Matthews, D. E., Schwarz, H. P., Yang, R. D., Motil, K. J., Young, V. R. & Bier, D. M. (1982) Relationship of plasma leucine and α-ketoisocaproate during a L-[I13]leucine infusion in man: a method for measuring human intracellular leucine tracer enrichment. Metabolism 31, 11051112.CrossRefGoogle Scholar
Motil, K. J., Matthews, D. E., Bier, D. M., Burke, J. F., Munro, H. N. & Young, V. R. (1981) Whole-body leucine and lysine metabolism: response to dietary protein intake in young men. American Journal of Physiology 240, E712E721.Google ScholarPubMed
Nissen, S. & Ostaszewski, P. (1985) Effects of supplemental energy on leucine metabolism in sheep. British Journal of Nutrition 54, 705712.Google ScholarPubMed
Oddy, V. H., Lindsay, D. B., Barker, P. J. & Northrop, A. J. (1987) Effect of insulin on hind-limb and whole body leucine and protein metabolism in fed and fasted lambs. British Journal of Nutrition 55, 143154.Google Scholar
Ørskov, E. R., Grubb, D. A., Wenham, W. & Corrigall, W. (1979) The sustenance of growing and fattening ruminants by intragastric infusion of volatile fatty acids and protein. British Journal of Nutrition 41, 553558.CrossRefGoogle Scholar
Ørskov, E. R. & MacLeod, N. A. (1982) The determination of the minimal nitrogen excretion in steers and dairy cows and its physiological and practical implications. British Journal of Nutrition 47, 625636.CrossRefGoogle ScholarPubMed
Reeds, P. J., Cadenhead, A., Fuller, M. F., Lobley, G. E. & McDonal, J. D. (1980) Protein turnover in growing pigs. Effect of age and food intake. British Journal of Nutrition 43, 445455.CrossRefGoogle ScholarPubMed
Reeds, P. J. & Lobley, G. E. (1980) Protein synthesis: are there real special differences? Proceedings of the Nutrition Society 39, 4352.CrossRefGoogle Scholar
Riis, P. M. (1983) The pools of tissue constituents and products: proteins. In Dynamic Biochemistry of Animal Production, pp. 75108 [Riis, P. M., editor]. Amsterdam: Elsevier.Google Scholar
Scornik, O. A. & Bothol, V. (1976) Role of changes in protein degradation in the growth of regenerating liver. Journal of Biological Chemistry 251, 28912897.CrossRefGoogle Scholar
Swick, R. W. & Ie, M. M. (1974) Measurement of protein turnover in rat liver with 14C-carbonate. Journal of Biological Chemistry 249, 68366841.CrossRefGoogle ScholarPubMed
Waterlow, J. C., Garlick, P. J. & Millward, D. J. (1978) Protein Turnover in Mammalian Tissues and in Whole-body. Amsterdam: North-Holland Publishing Company.Google Scholar
Waterlow, J. C., Golden, M. H. N. & Picou, D. (1977) The measurement of rates of protein turnover, synthesis, and breakdown in man and the effects of nutrition status and surgical injury. American Journal of Clinical Nutrition 30, 13331339.CrossRefGoogle ScholarPubMed
Young, V. R., Stothers, S. C. & Vilaire, G. (1971) Synthesis and degradation of mixed proteins, and composition changes in skeletal muscle of malnourished and refed rats. Journal of Nutrition 101, 13791390.CrossRefGoogle ScholarPubMed