ESTIMATION OF NITRATE CONTENT IN RAW COW’S MILK DURING THE YEAR

Abstract

Foods of animal origin are less controlled by nitrate content (except sausages), since they are not a potential source of consumers of these substances into the body. At the same time, cow’s milk can also be a source of additional nitrate intake into the body, so it is especially relevant to monitor their content in milk, which is a daily component of many consumers, including children. The purpose of this work was to determine the possible seasons of changes in the number of nitrates in the milk of cow-obtained from two breeds of cows-Holstein and Black-Rawbi. Increased nitrate content in milk can occur due to the entry of nitrates into the cow’s components with feed or water, especially in conditions of violation of feeding technology, reduced activity of rumen microflora or poor-quality feed. Therefore, the efficiency of nitrate conversion in the digestive tract of cows directly affects the quality of dairy products. To determine the amount of nitrates in milk used a standard method using cadmium recovery and analysis of injection flow after dialysis. It is established that in the milk raw from the Holstein and black-and-white breeds of cows in the summer months, the content of nitrates did not differ significantly and was from 2,9 to 6,5 mg/kg of milk. However, no significant dependence on the effect of cows on the content of nitrates in milk at the same diet and animal feeding was not revealed. It is established that in March, the content of nitrates in the milk of Holstein and black-and-white breeds of cows in all farms was probably higher than in January. In addition, in March on farms № 2 and № 3 with Holstein rocks of cows and in two with black and gap, the number of nitrates in milk exceeded, although not significant in 10 mg/kg. Therefore, the possible increase in the content of nitrates in milk requires more thorough research on the mechanisms of their intake into milk with modern technology of keeping and feeding cows.