Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-12-02T05:31:53.148Z Has data issue: false hasContentIssue false
  • English
  • Français

Effects of feeding ryegrass of varying maturity on the metabolism and composition of lipids in the rumen of sheep

Published online by Cambridge University Press:  27 March 2009

T. Gerson ,
A. John  and
A. S. D. King
T. Gerson
Affiliation:
Department of Scientific and Industrial Research, Applied Biochemistry Division, Palmerston North, New Zealand
A. John
Affiliation:
Department of Scientific and Industrial Research, Applied Biochemistry Division, Palmerston North, New Zealand
A. S. D. King
Affiliation:
Department of Scientific and Industrial Research, Applied Biochemistry Division, Palmerston North, New Zealand
Get access Rights & Permissions [Opens in a new window]

Summary

Two experiments were carried out to test the effects of ryegrass maturity on rumen lipid metabolism. In the first experiment the effect of stage of maturity of perennial ryegrass on lipid metabolism in the rumen was studied with grazing sheep fitted with rumen cannulae. The pasture was either immature (13·8% crude protein), mature (8·1% crude protein) or senescent (5·5% crude protein).

The rates in vitro of triacyl glycerol lipolysis and linoleic acid (18: 2w6) hydrogenation were found to decrease with increasing age of the ryegrass.

In the second experiment the sheep were dosed with emulsified linseed oil (30 g) via rumen cannulae while grazing immature or senescent ryegrass and the rumen digesta and blood plasma sampled at 0, 4 and 8 h after dosing.

The proportions of linseed oil retained in the rumen were greater and blood plasma linoleic (18:2w6) and linolenic (18:3w3) acid concentrations higher when senescent ryegrass was fed.

It was concluded that the rates of rumen lipolysis and hydrogenation decreased with the age of pasture and that after dosing with linseed oil the polyunsaturated fatty acid concentrations in blood plasma increased.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 106 , Issue 3 , June 1986 , pp. 445 - 448
Copyright
Copyright © Cambridge University Press 1986

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

Body, D. R. & Hansen, R. P. (1978). The occurrence of C13 to C31 branched chain fatty acids in the faeces of sheep fed ryegrass, and of C12 to C34 normal acids in both the faeces and the ryegrass. Journal of the Science of Food and Agriculture 29, 107–114.CrossRefGoogle Scholar
Gerson, T., John, A. & King, A. S. D. (1985). The effects of dietary starch and fibre on the in vitro rates of lipolysis and hydrogenation by sheep rumen digesta. Journal of Agricultural Science, Cambridge 105, 27–30.CrossRefGoogle Scholar
Gerson, T., John, A., Shelton, I. D. & Sinclair, B. R. (1982). Effect of dietary N on lipids of rumen digesta, plasma, liver, muscle and perirenal fat in sheep. Journal of Agricultural Science, Cambridge 99, 71–78.CrossRefGoogle Scholar
Gerson, T., John, A. & Sinclair, B. R. (1983). The effect of dietary N on in vitro lipolysis and fatty acid hydrogenation in rumen digesta from sheep fed diets high in starch. Journal of Agricultural Science, Cambridge 101, 97–101.Google Scholar
Hobson, P. N. & Wallace, R. J. (1982). Microbial ecology and activities in the rumen: part 1. CRC Critical Reviews in Microbiology 9, 165–225.Google Scholar
Kemp, P. & Lander, D. J. (1984). Hydrogenation in vitro of α-linolenic acid to stearic acid by mixed cultures of pure strains Of rumen bacteria. Journal of General Microbiology 130, 527–533.Google Scholar
Latham, M. J., Storry, J. E. & Sharpe, M. E. (1972). Effect of low-roughage diets on the microflora and lipid metabolism in the rumen. Applied Microbiology 24, 871–877.CrossRefGoogle ScholarPubMed
Leat, W. F. M. (1977). Depot fatty acids of Aberdeen Angus and Friesian cattle reared on hay and barley diets. Journal of Agricultural Science, Cambridge 89, 575–582.Google Scholar
Moore, J. H., Noble, R. C. & Steele, W. (1968). Factors affecting the polyunsaturated fatty acid content of the plasma lipids of sheep. British Journal of Nutrition 22, 681–688.CrossRefGoogle ScholarPubMed