FATTY ACIDS OF MILK AND THE INTENSITY OF S. AUREUS SECRETION IN COWS WITH SUBCLINICAL MASTITIS IN THE STEPPE OF UKRAINE

Abstract

The consumption of raw drinking milk and pasteurised drinking milk is a topic still widely debated around the world. Raw drinking milk, as for its biological safety, can pose a number of hazards to human health. However, pasteurised milk, too, can vary in its biological value. The composition of milk directly depends on the physiological state of the mammary gland. So, taking into account the intensity of fatty acid exchange in this organ, it can be assumed that the physiological state of dairy cows’ mammary gland can affect the biological value of the secretion, in particular, its fatty acid composition. The paper shows the changes in the fatty acid composition of milk, depending on how intensely the mastitic lesion of the mammary gland has developed, ranging from the subclinical form of the disease (the signs of the disease are unmanifest) to the clinical form (the signs of the disease are clearly manifest). Cows with the subclinical form of mastitis pose the greatest biohazard: they show no clinical signs of the disease, so raw milk from these cows more easily finds its way onto numerous markets. The research was conducted in 974 dairy cows of various breeds in 6 farms of the steppe zone of Ukraine (Odesa, Mykolaiv, and Poltava regions). Each of the forms of mastitis (subclinical and clinical) has been found in about 20% of the dairy livestock. The main pathogen causing mammary gland infection is Staphylococcus aureus bacteria (36.6-47.4%). Changes in the fatty acid composition of milk of cows with subclinical mastitis have been shown. It has been established that the proportion of long-chain fatty acids decreases and the percentage of short-chain fatty acids increases, along with a decrease in mono- and polyunsaturated fatty acids. It has been proved that that the subclinical form of mastitis affects the content of C4:0, C10:0 (ղ²ᵪ = 0.90–0.94 arb. units; р<0.001), and C18:1n9c (ղ²ᵪ = 0.36–0.84 arb. units; р<0.001) in cow’s milk. With the cows’ clinical recovery, the content of all fatty acids in milk does not immediately return to the indicators observed before the disease.