Fatty acid profile of ewe’s milk infected with Staphylococcus spp.

Mastitis in sheep caused by Staphylococcus spp. is a serious concern for dairy farming.

The objective of this study was to evaluate the impact of the intramammary infection (IMI) caused by Staphylococcus spp. on the long-chain fatty acid profile and composition of ewe’s milk.

The experiment was conducted in a herd of Zoslachtena Valaska sheep. Half-udder milk samples were collected from 20 weight-matched sheep at the peak of their first or second lactation. The basic physicochemical composition of milk, somatic cell count (SCC), Staphylococcus spp. infection, and total bacterial contamination (TBC) were determined. The fatty acid profile of the milk fat was determined using gas chromatography.

The SCC in milk infected with Staphylococcus spp. was 3.25 times higher (P<0.01) than that in the uninfected milk samples. The content of lauric acid (С12:0) was higher (P<0.05) in the milk fat of infected ewes. A significant increase (P<0.05) in the share of linoleic acid (C18:2n6t), arachidonic acid (C20:4n6), and a decrease (P<0.01) in the vaccenic acid (C18:1n7t) were observed in the milk collected from ewes infected with Staphylococcus spp.. Staphylococcus spp. infection increased the ratio of n-6 to n-3 polyunsaturated fatty acids.

Changes in the fatty acid profile of milk caused by Staphylococcus spp. infection decrease the value of ewes’ milk as a health-promoting product.