Increasing health effect of milk and milk product by modifying feeding of the animals

Nikolay Todorov

Abstract: An increasing interest for enhancing the conjugated linoleic acids (CLA) content in milk fat is connected with its potential anti-carcinogenic, ant-diabetic, anti-obesity, anti-atherogenic and immunomodulatory functions. It is synthesized in the rumen from linoleic acid or endogenously from trans-vaccenic acid (trans-11, C18:1) by Δ9 desaturase. About 28 CLA isomers are possible, of which those with known healthy biological activities are cis-9, trans-11 comprising 80 – 90%, and trans-10, cis-12 comprising 3 – 5% of total CLA. Another isomer of quantitative importance is trans-7, cis-9, which comprises 3 – 16% is obviously not active biologically. Increasing CLA content of milk fat is possible by modifying diet of animals. Positive effect has inclusion of more forage instead of concentrate, using fresh pasture vs. preserved feeds, addition of linoleic and linolenic acids as oil bearing seeds or oil and some fish oil, and maintaining pH into rumen above 6. A second factor is animal-to-animal variation connected with activity of Δ9 desaturase, while processing of milk and meat appear to be of minor importance. It seems that there are not significant differences in CLA content of milk fat of cows, water buffaloes, ewes as well as between fat of colastrum and milk, and as a consequence milk or colastrum richer in fat is better sours of CLA. It is difficult to establish at the moment correct doses of CLA for prevention of human cancers. It’s expected that level of CLA in the blood plasma is better indicator of real dose, than intake of CLA.

Keywords: breed; colastrum; Conjugated linoleic acid; diet; fat; individual; milk

Date published: 2023-03-07