Comparative evaluation of the milk composition of dairy cows in the Volgograd region

The article presents the results of determining the indicators of milk productivity of dairy cows in the Volgograd region. The studies processed the data of monthly control milking of five large agricultural enterprises of the region (LLC JV "Donskoe" Kalachevsky district, PZK "Put Lenina" Surovikinsky district, "Vostok" Nikolaevsky district, "PZK named after Lenin" Surovikinsky district, FSUE "Irrigated" Sovetsky district ). A comparative characteristic of the milk yield of the presented breeds of cattle in different periods of the year is given. Physicochemical definitions of milk quality indicators were carried out according to generally accepted methods - fat content (GOST R ISO 2446-2011) and protein (GOST 23327-98). A comparative analysis of the fat and protein content in the milk of dairy cows by periods of the year is presented. To analyze the chemical composition of milk samples by inductively coupled plasma mass spectrometry (ICP-MS), a Nexion 300D quadrupole mass spectrometer (Perkin Elmer, USA) was used. The determination of the chemical composition of milk samples by inductively coupled plasma atomic emission spectrometry (ICP AES) was carried out using an Ortima 2000DV atomic emission spectrometer (Perkin Elmer, USA). The results obtained showed the content of chemical elements in the milk of cows in the summer period within the limits of permissible concentrations, including the content of heavy metals (cadmium, mercury, lead, arsenic). Studies carried out with milk samples obtained from animals from all experimental farms have shown that the controlled indicators of milk quality, the content of chemical elements correspond to regulatory documents and raw milk of all farms is recommended for use in the production of all types of fermented milk and dairy products.