Impact of lactation stage and milk production on milk fat fatty acids ratio
2012
Foltys, V., Animal Production Research Centre, Nitra (Slovak Republic) | Kirchnerová, K., Animal Production Research Centre, Nitra (Slovak Republic)
Milk fat is, from a nutritional point of view, of the negative value because of the prevalent content of saturated fatty acids with high atherogenic index. Intake of milk fat in the diet is important because of the content of monounsaturated fatty acids, acting favorably against cardiovascular diseases and especially of essential fatty acids: linoleic, alpha-linolenic and conjugated linoleic acid (CLA), which is found only in meat and milk of ruminants. The analysis of relations of fatty acids in milk fat to qualitative-production parameters of milk shows that the correlations of fatty acids with lactation stage and qualitative-production parameters of milk are quite weak in dairy cows with stable type of nutrition in form of whole-the-year feeding mixed feed ration in lowland agricultural area. Coefficients r more than 0.3 for the values of lactation sum were observed at monounsaturated fatty acids (MUFASC), r = 0.467 for days, 0.307 for milk, 0.353 for fat, and 0.340 for protein total production. The most important fatty acids, as far as their content is concerned, C12:0, C14:0, C16:0, C18:0, C18:1n9, the ratio of which is higher than 5 % in milk fat and they represent together about 75 % of milk fat, show no significant relations either to sum or to daily production parameters or to the content of basic components in milk. With the exception of C16:0, palmitic acid (30.93 plus minus 4.81 % in milk fat), which has negative relation to daily milk (r = -0.404) and protein (r = -0.345) production. This acid has positive relation to the content of fat in milk (r = 0.444) and negative relation to the content of lactose in milk (r = -0.311). CLA showed negative correlation with daily fat production (r = -0.407) and content of fat in milk (r = -0.269) and F/P index (r = -0.420).
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