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Changes in the conjugated linoleic acid content of milk from dairy cows throughout the year

  • A.L. Lock (a1) and P.C. Garnsworthy (a1)

Abstract

Conjugated linoleic acid (CLA) is a naturally occurring anticarcinogen found in dairy products which is produced in the rumen as an intermediate in the biohydrogenation of polyunsaturated fatty acids by the bacteria Butyrivibrio fibrivsolvens. An experiment was conducted to examine the changes in CLA concentration in bovine milk throughout the year. 338 milk samples were taken from the University of Nottingham's commercial dairy herd between December 1997 and March 1999. All animals followed the same dietary regime throughout the study. Samples were analysed for fat and CLA content. Morning and evening samples were pooled to calculate daily fat and CLA concentrations and yields. There was a small variation in milk yield (P<0.05) whereas CLA content and yield varied considerably (P<0.001) throughout the year (CLA = 0.91 to 2.81 mg/g of fat). The highest concentrations were found during the summer months when the cows were mainly eating fresh grass as opposed to conserved forages. Fat content and yield followed by the month were the predominant factors affecting CLA output. Results indicate that, if required, CLA in milk could be increased through suitable dietary management practices.

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References AOAC 1990. AOAC Official Methods of Analysis: Food Composition; Additives; Natural Contaminants Volume Two: 812814.
Doll, R. 1992. The lessons of life – keynote address to the Nutrition and Cancer Conference. Cancer Research 52:s2024s2029.
Ha, Y.L., Grimm, N.K. and Pariza, M.W. 1987. Anticarcinogens from ground beef: heat altered derivatives of linoleic acid. Carcinogenesis 8: 18811887.
Ha, Y.L., Storkson, J. and Pariza, M.W. 1990. Inhibition of benzo(a)pyrene-induced mouse forestomach neoplasia by conjugated dienoic derivatives of linoleic acid. Cancer Research 50: 10971101.
Jiang, J., Bjoerck, L., Fonden, R. and Emanuelson, M. 1996. Occurrence of conjugated Cis-9, trans-11-octadecadienoic acid in bovine milk: Effects of feed and dietary regimen. Journal of Dairy Science 79: 438445.
Kelly, M.L., Berry, J.R., Dwyer, D.A., Griinari, J.M., Chouinard, P.Y., Van Amburgh, M.E. and Bauman, D.E. 1998. Dietary fatty acid source affects conjugated linoleic acid concentrations in milk from lactating cows. Journal of Nutrition 128: 881885.
Kepler, C.R. and Tove, S.B. 1967. Biohydrogenation of unsaturated fatty acids III. Purification and properties of a linoleate cis-12, trans-11 isomerase from Butyrivibrio fibrivsolvens . Journal of Biological Chemistry 242: 56865692.
Lin, H., Boylston, T.D., Chang, M.J., Luedecke, L.O. and Shultz, T.D. 1995. Survey of the conjugated linoleic acid contents of dairy products. Journal of Dairy Science: 23582365.
Lough, A.K. and Anderson, L.J. 1973. Effect of ensilage on the lipids of pasture grass. Proceedings of the Nutrition Society 32: 61A62A.
Parodi, P.W. 1994. Conjugated Linoleic Acid – an anticarcinogenic fatty acid present in milk fat. Australian Journal of Dairy Technology 49: 9397.
Parodi, P.W. 1997. Cows’ milk fat components as potential anticarcinogenic agents. Journal of Nutrition 127: 10551060.

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