بررسي حساسيت و ويژگي دستگاه MAS-D-TEC جهت شناسايي اورام پستان تحت باليني در گاوهاي شيري

Sensitivity and specificity of MAS-D-TEC device to detect subclinical mastitis in dairy cows

Early diagnosis of subclinical mastitis in dairy cows may be important in reducing production loss and enhancing prospects of recovery. In recent years, most effort has gone into the system that uses changes in the electrical conductivity of milk. The purpose of this study was to evaluate the sensitivity (Se) and specificity (Sp) of MAS-D-TEC (a manually cowside detector of mastitis, Westcor Inc., Logan, USA) for detection of subclinical mastitis by changes in electrical conductiviy of foremilk. Foremilk samples of each cow fn-236 quarters) were first examined by MAS-D-TEC device and then by CMT procedure. MAS-D-TEC graded from 0 to 9. On the basis of the lactory recommendation, sample grades >5 are highly indicative of presence of infection. Quarter milk samples were then collected aseptically and sent to the diagnostic Lab. For bacteriological cultures on blood agar and MacConkey agar media. The results of this study revealed that on the basis of the factory recommendation, Se of MAS-D-TEC for detection of subclinical mastitis was 100% , but the Sp of this device was 43.3%. if the border grade change to >6 and <5, so the Se and Sp of this procedure change to 96.4% and 60% respectively. The false positive results of this device to detect subclinical mastitis may be attributed to the stage of lactation, parity, presence of the pathogen in the milk cells, presence of other microorganisms other than bacteria in the sample, and so on. In conclusion, the present study revealed that milk specimens with degrees <4 in MAS-D-TEC procedure are highly indicative of absence of pathogens in the udder, but specimens with degrees >5 may be indicative of subclinical mastitis which bacteriological cultures must be done to ascertain the presence of bacteria and kind of pathogens involved, necessary for control and preventive mastitis programs in dairy herds.