Comparative assessment of modern methods of diagnosis of subclinical mastitis in cows

Abstract

Diseases of the mammary gland, among which mastitis is the most common, cause significant damage to dairy farming. On different farms, from 3 to 50% of lactating cows are sick, and only in 30% of cases the disease manifests itself clinically, and in most cases it has a subclinical course. Early diagnosis of the subclinical stage of mastitis is of great economic, sanitary and technological importance. The effectiveness of timely treatment of sick animals and prevention of the clinical stage of mastitis and ensuring normal milk quality largely depends on it. The study was conducted at the National Research Center of the Ukrainian National Academy of Sciences on 92 lactating cows of the Ukrainian black-spotted breed. Each animal was diagnosed with clinical and subclinical mastitis. Research on subclinical mastitis was carried out using the German milk test and determining the electrical resistance of milk. The diagnostic value of these methods of settling breakdown was monitored. According to the results of the standing test, subclinical mastitis was detected in 30 (32.6%) of 92 lactating cows during the study (49 quarters were affected). Indirect determination of the number of somatic cells using the German milk test allows rapid diagnosis of subclinical mastitis with an accuracy of 84.8%. The use of the "Electronic determinant of mastitis in cows" with the interpretation of the obtained results according to the value of electrical resistance or the difference between the indicators of individual quarters according to the instructions ensures the accuracy of the result in 82.6 and 91.3% of cases, respectively. It is advisable to interpret the indicators of electrical resistance of milk taking into account both indicators. At the same time, cows with indicators of the numerical value of the electrical resistance of milk of 340 (u).o. should be considered healthy. and more and with a difference between the indicators of the quarters of 50 (u).o. and less; for sick animals, the electrical resistance of the secretion of the mammary gland in the range of 260 (u).o. is characteristic. And less with a difference between the largest and smallest indicators of individual quarters of 100 (u).o. and more. A diagnosis of subclinical mastitis can be considered doubtful if the electrical resistance of milk is between 270 and 330 (u).o. and differences between indicators of quarters 60 - 90 (u).o. Key words: cows, subclinical mastitis, electronic mastitis detector, EIMU.