Species composition of microbiota of cows udder and raw milk quality at mastitis

Abstract

To increase the productivity of cows and improve the nutritional and sanitary-technological qualities of milk is one of the most important tasks in the development of dairy farming in all countries of the world. The cause of degradation of these parameters is such a widespread disease of cows as mastitis. The social significance of mastitis is manifested in the fact that the causative agents of mastitis in cows can cause disease in humans. Since streptococci and staphylococci play a leading role in mastitis, they are the most common in milk. Studies have shown that udder disease in cows with mastitis at the beginning of lactation has a certain seasonal nature and its main peaks occur in March-May and September-November. During these months, from 2.5% to 4.1% of cows from the total number of livestock of the farm were found to have mastitis. Physiochemical features of milk from the cows with mastitis were an increase in the number of somatic cells to 1,500,000/cm3, increase of milk pH to 7.3, caused by the breakdown of milk proteins into ammonia, the increase in milk electrical conductivity to 5.92-7.54 mS/cm, associated with the entry of sodium and chlorine ions from the blood into the milk. In studies of cows with mastitis, 16 species of bacteria were isolated from the secretion of the udder. In monoculture, the microflora, that was found in 30.5% of cows, consisted of E. coli, St. epidermidis, C. freundi, Sh. Dysentery, St. aureus, St. hyicus spp. Chromogenes, Str. Agalactiae, St. lentus, and St. intermediate. In 69.5% of cows with mastitis, the microflora was found in various associations. The most common associations of bacteria were St. epidermidis + St. aureus + Str. agalactiae + Str. haemolyticus; E. coli + Str. agalactiae; Str. agalactiae + St. epidermidis; St. epidermidis + St. aureus + Str. agalactiae. We developed a method for diagnosing mastitis in cows, which was to diagnose the disease at early stage of inflammation of the mammary glands by studying the composition of the milk the examined lobe of the udder.