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Observations on the influence of high cell count on lipolysis in bovine milk

Published online by Cambridge University Press:  01 June 2009

Amer M. A. Salih
Affiliation:
National Institute for Research in Dairying, Shinfield, Reading, RG2 9AT
Malcolm Anderson
Affiliation:
National Institute for Research in Dairying, Shinfield, Reading, RG2 9AT

Summary

The effect that changes in composition which occur in milks possessing high cell counts have on milk lipolysis has been investigated. High cell counts were produced either by intramammary infusion of Escherichia coli endotoxin or Streptococcus agalactiae or by addition of washed cells which were isolated from milk obtained from quarters infused with endotoxin. Free fatty acid levels in milk were measured in terms of acid degree value (ADV) either as initial ADV measured immediately after milking or ADV developed after a prescribed incubation period.

There was an increase in initial ADV after the infusion either of endotoxin or of Str. agalactiae relative to a control quarter. This increase appeared to be associated with changes in cell count, but in absolute terms the influence of cells on ADV became less as cell count increased. Neither type of infusion had any effect on lipoprotein lipase activity. The addition of washed cells to normal milk resulted in an increase in developed ADV, but the increment was not as large as that produced by the addition of 1% blood serum. When cream and skim-milk from endotoxin-treated quarters and control quarters were mixed in different combinations with and without additional cells, developed ADV was higher in those samples containing endotoxin cream and those with added cells. Milk from a quarter treated with endotoxin was diluted with its own skim-milk to produce different cell counts and ADV was determined after various time intervals at 4 and 37 °C. Lipolysis increased with increasing cell count, but a depression in lipolytic rate was noted after incubation for 6 h at 4 °C and 20 min at 37 °C.

The proportion of skim-milk lipoprotein lipase activity in milk serum was larger both in milks possessing high cell counts and in normal milk adjusted to between 5 and 20 mM-NaCl by addition of solid NaCl. These levels of NaCl inhibited lipolysis.

The possible direct and indirect effects of high cell count on milk lipolysis are discussed.

Type
Original Articles
Copyright
Copyright © Proprietors of Journal of Dairy Research 1979

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References

REFERENCES

Anderson, M. (1977). Journal of Dairy Science 60, 1217.CrossRefGoogle Scholar
Anderson, M. & Andrews, A. T. (1977). Journal of Dairy Research 44, 223.CrossRefGoogle Scholar
British Standards Institution (1969). B.S. no. 696, Part II, p. 7.Google Scholar
Brumby, P. E., Storry, J. E. & Sutton, J. D. (1972). Journal of Dairy Research 39, 167.CrossRefGoogle Scholar
Castbero, H. B. & Solberg, P. (1974). Meieriposten 63, 961.Google Scholar
Christie, W. W. (1974). Lipids 9, 876.CrossRefGoogle Scholar
Christie, W. W. & Wooding, F. B. P. (1975). Experientia 31, 1445.CrossRefGoogle Scholar
Deeth, H. C. (1978). 20th International Dairy Congress, Paris E, 364.Google Scholar
Deeth, H. C. & Fitzgerald, C. H. (1978). 20th International Dairy Congress, Paris E, 308.Google Scholar
Downey, W. K. (1974). 19th International Dairy Congress, New Delhi 1E, 323.Google Scholar
Downey, W. K. & Andrews, P. (1966). Biochemical Journal 101, 651.CrossRefGoogle Scholar
Driessen, F. M. & Stadhouders, J. (1974). Netherlands Milk and Dairy Journal 28, 130.Google Scholar
Fielding, C. J. & Fielding, P. E. (1976). Journal of Lipid Research 17, 248.Google Scholar
Gaffney, P. J. & Harper, W. J. (1965). Journal of Dairy Science 48, 613.CrossRefGoogle Scholar
Hoynes, M. C. T. & Downey, W. K. (1973). Biochemical Society Transactions 1, 256.CrossRefGoogle Scholar
International Dairy Federation (1971). Annual Bulletin, Part 2, Appendix 1.Google Scholar
Iverius, P. H., Lindahl, U., Egelrud, T. & Olivecrona, T. (1972). Journal of Biological Chemistry 247, 6610.CrossRefGoogle Scholar
Jellema, A. (1975). Netherlands Milk and Dairy Journal 29, 145.Google Scholar
Linzell, J. L. & Peaker, M. (1972). British Veterinary Journal 128, 284.CrossRefGoogle Scholar
Luhtala, A., Korhonen, H., Koskinen, E. H. & Antila, M. (1970 a). 18th International Dairy Congress, Sydney 1E, 80.Google Scholar
Luhtala, A., Koskinen, E. H. & Antila, M. (1970 b). 18th International Dairy Congress, Sydney 1E, 79.Google Scholar
McCarthy, R. D. & Patton, S. (1964). Nature, London 202, 347.CrossRefGoogle Scholar
Newbould, F. H. S. (1974). In Lactation, vol. 2, p. 269. (Eds Larson, B. L. and Smith., V. R.) New York: Academio Press.Google Scholar
Olivecrona, T. & Lindahl, U. (1969). Acta Chemica Scandinavica 23, 3587.CrossRefGoogle Scholar
Randolph, H. E. & Erwin, R. E. (1974). Journal of Dairy Science 57, 865.CrossRefGoogle Scholar
Russell, M. W. (1973). Thesis, University of Reading.Google Scholar
Salih, A. M. A. (1978). Thesis, University of Reading.Google Scholar
Salih, A. M. A., Anderson, M. & Tuckley, B. (1977). Journal of Dairy Research 44, 601.CrossRefGoogle Scholar
Tallamy, P. T. & Randolph, H. E. (1969). Journal of Dairy Science 52, 1569.Google Scholar
Tarassuk, N. P. & Yaguchi, M. (1958). Journal of Dairy Science 41, 1482.Google Scholar