DBPapers
DOI: 10.5593/sgem2017/61/S25.123

RESEARCHES REGARDING THE PROFILE OF FATTY ACIDS IN THE MILK RESULTING FROM COWS DIAGNOSED WITH SUB-CLINICAL MASTITIS

M. Cola, F. Cola
Tuesday 12 September 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7408-12-6 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 61, 939-946 pp, DOI: 10.5593/sgem2017/61/S25.123

ABSTRACT

The effect of mastitis on the content and composition of the milk lipids is not fully known yet, the literature presenting numerous contradicting data. In this work it was aimed to emphasize the modifications occurred at the level of the composition in fatty acids and cholesterol, as well as to establish the level of peroxidation of lipids in the milk resulting from cows with sub-clinical mastitis as compared to the milk resulting from healthy cows.
Thus, within the researches carried out in 2016 in Olt county there were pursued the following general objectives: to assess the level of oxidative degradation of lipids resulting from healthy cows and cows diagnosed with sub-clinical mastitis; to determine the enzyme antioxidant status at blood level and at milk level (both in case of samples collected from healthy cows and from cows diagnosed with sub-clinical mastitis). The determined enzymes were the following: catalase, superoxide dismutase and glutathionperoxidase. The level of peroxidase of lipids present in milk were determined photometrically, through the method based on the reaction with thiobarbituric acid, and the determination of the activity of antioxidant enzyme in blood was carried out using analysis kits like Cayman, Ransel, Hospitex. Malonildialdehide, the product resulted by oxidation of polyunsaturated fatty acids is used as marker of lipid peroxidation [6]. The results obtained (table 4) showed that mastitic milk contains a concentration significantly higher of malonildialdehide as compared to the normal one. In case of samples of mastitic milk, the ratio polyunsaturated fatty acids/saturated fatty acids is smaller than the normal milk (table 3). We can say that in the mastitic milk occurs an intensification of oxidative processes at lipid level, as result of the increase of the number of somatic cells, the results obtained being compliant with those presented by other authors [8;13]. The results obtained in case of blood catalase show that the activity of this enzyme does not present significant modifications. Thus, in case of cows with sub-clinical mastitis, the average values were of 2.05 U/mg Hb while in case of healthy animals the average values were of 1.46 U/mg Hb. In the case of samples of milk analysed we noticed the increase of catalasic activity in mastitic milk as compared to the normal one. As it can be noticed in table 5, the superoxide dismutase activity has average values comprised between 1.044 U/ml resulting from the milk of healthy cows and 1,066 U/ml in the milk resulting from the cows with sub-clinical mastitis, both values being close to the normal limits presented in the literature. Also, at blood level there are no significant modifications in the superoxide disamutase activity. As for the glutathion-peroxidase activity, this one significantly increases (4 times more) in mastitis milk as compared to the normal one.

Keywords: mastitic milk; saturated fatty acids; haemoglobin; lipids.