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Metabolism of lactic acid isomers in the rumen of silage-fed sheep

Published online by Cambridge University Press:  09 March 2007

M. Gill
Affiliation:
The Grassland Research Institute*, Hurley, Maidenhead, Berkshire SL6 5LR
R. C. Siddons
Affiliation:
The Grassland Research Institute*, Hurley, Maidenhead, Berkshire SL6 5LR
D. E. Beever
Affiliation:
The Grassland Research Institute*, Hurley, Maidenhead, Berkshire SL6 5LR
J. B. Rowe
Affiliation:
ICI Pharmaceutical Division, Alderley Park, Macclesfield, Cheshire SK10 4TG
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Abstract

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1. Four mature sheep were offered perennial ryegrass (Lolium perenne, cv. S23) silage (885 g dry matter/d) at hourly intervals. The silage was well fermented with a pH of 4.0, a lactic acid content of 139 g/kg dry matter and an organic matter digestibility of 0.766.

2. Continuous intraruminal infusions of 14C-labelled sodium salts of [U-14C]acetic acid, [2-14C]propionic acid, [2-14C]butyric acid and D- and L-[U-14C]lactic acid and an intravenous infusion of [U-14C]glucose were made on separate occasions to estimate the fluxes of rumen acetate, propionate, butyrate and lactate as well as plasma glucose. The data were resolved by the use of appropriate four-compartment (rumen) and three-compartment (rumen-plasma) models.

3. Irreversible loss rate (g C/h) of rumen acetate (5.32 g C/h) was considerably greater than values obtained for propionate (2.58), butyrate (2.80) and lactate (2.91).

4. Total flux of lactate (1.83 mol/d) exceeded the amount of lactate consumed in the diet (1.37 mol/d) indicating a net synthesis of 0.46 mol lactate/d. Approximately 0.90 of total lactate flux was metabolized in the rumen, with 1.00 mol/d converted to acetate, 0.57 to propionate and 0.08 to butyrate. The flux to acetate was significantly (P < 0.05) greater than that to propionate. Both the D- and L-isomers appeared to have similar metabolic fates.

5. Lactate appeared to make no direct contribution to glucose flux in the animal, but 0.10 of total lactate was converted to glucose through propionate.

6. The results are discussed in relation to overall lactate metabolism, and it is suggested that almost 0.30 of ruminally digested organic matter may be fermented via lactate.

Type
Papers on General Nutrition
Copyright
Copyright © The Nutrition Society 1986

References

REFERENCES

Baldwin, R. L., Wood, W. A. & Emery, R. S. (1962). Journal of Bacteriology 83, 907913.CrossRefGoogle Scholar
Beever, D. E. (1980). In Forage Conservation in the 80's. Occasional Symposium no. 11, pp. 131143 [Thomas, C., editor]. Hurley: British Grassland Society.Google Scholar
Bergmann, E. N., Roe, W. E. & Kon, K. (1966). American Journal of Physiology 211, 793799.CrossRefGoogle Scholar
Chamberlain, D. G., Thomas, P. C. & Anderson, F. J. (1983). Journal of Agricultural Science, Cambridge 101, 47–58.CrossRefGoogle Scholar
Cottyn, B. G. & Boucque, C. U. (1968). Journal of Agricultural and Food Chemistry 16, 105107.CrossRefGoogle Scholar
Counotte, G. H. M. (1981). Regulation of lactate metabolism in the rumen. PhD Thesis, University of Utrecht.CrossRefGoogle Scholar
Dewar, W. A. & MacDonald, P. (1961). Journal of the Science of Food and Agriculture 12, 790795.CrossRefGoogle Scholar
Dunlop, R. H. & Hammond, P. B. (1965). Annals of the New York Academy of Science 119, 11091113.CrossRefGoogle Scholar
Elsden, S. R. & Gibson, Q. M. (1954). Biochemical Journal 58, 154158.CrossRefGoogle Scholar
Emery, R. S., Thomas, J. W. & Brown, L. D. (1966). Journal of Animal Science 25, 379401.CrossRefGoogle Scholar
Gill, M. & Beever, D. E. (1982). British Journal of Nutrition 48, 3747.CrossRefGoogle Scholar
Gill, M., Siddons, R. C., Beever, D. E. & Rowe, J. B. (1984). Canadian Journal of Animal Science 64, Suppl., 169170.CrossRefGoogle Scholar
Jayasuriya, G. C. N. & Hungate, R. E. (1959). Archives of Biochemistry & Biophysics 82, 274287.CrossRefGoogle Scholar
Judson, G. J. & Leng, R. A. (1973). British Journal of Nutrition 29, 175194.CrossRefGoogle Scholar
Leng, R. A. & Leonard, G. J. (1965). British Journal of Nutrition 19, 469484.CrossRefGoogle Scholar
MacRae, J. C. & Lobley, G. E. (1982). Livestock Production Science 9, 447456.CrossRefGoogle Scholar
Nolan, J. V., Norton, V. W. & Leng, R. A. (1976). British Journal of Nutrition 35, 127147.CrossRefGoogle Scholar
Rowe, J. B., Davies, A., Hinchcliffe, P. M. & Broome, A. W. J. (1982). Laboratory Practice 31, 2324.Google Scholar
Ryan, H. (1958). Analyst 83, 528531.CrossRefGoogle Scholar
Schmidt, S. P., Smith, J. A. & Young, J. W. (1975). Journal of of Dairy Science 58, 952956.CrossRefGoogle Scholar
Siddons, R. C., Evans, R. T. & Beever, D. E. (1979). British Journal of Nutrition 42, 535545.CrossRefGoogle Scholar
Somogyi, M. (1945). Journal of Biological Chemistry 160, 6973.CrossRefGoogle Scholar
Stanier, G. & Davies, A. (1981). British Journal of Nutrition 45, 567578.CrossRefGoogle Scholar
Terry, R. A. & Osbourn, D. F. (1980). In Forage Conservation in the 80's. Occasional Symposium no.11, pp. 315330 [Thomas, C., editor]. Hurley: British Grassland Society.Google Scholar
Thomas, P. C. (1982). In Forage Protein in Ruminant Animal Production. Occasional Symposium no. 6, pp. 6778 [Thomson, D. J., Beever, D. E. and Gunn, R. G., editors]. Thames Ditton: British Society of Animal Production.Google Scholar
Waldo, D. R. & Schultz, L. H. (1956). Journal of Dairy Science 39, 14531460.CrossRefGoogle Scholar
Williams, V. J. & MacKenzie, D. D. S. (1965). Australian Journal of Biological Science 18, 917934.CrossRefGoogle Scholar
Wilson, R. F. & Wilkins, R. J. (1972). Journal of Science of Food and Agriculture 23, 377385.CrossRefGoogle Scholar
Wood, W. A. (1961). In The Bacteria, vol. 2, pp. 103108 [Gunsalus, I. C. and Stanier, R. Y., editors]. New York: Academic Press.Google Scholar