COMPARISON OF MILK QUALITY GAUGE (MQG) WITH WISCONSIN MASTITIS TEST (WMT)

The MQG, a cowside, screening test for abnormal milk, is based on observing the rate of flow of warm milk under vacuum through a dense test disk. The MQG, as applied to individual cow and herd milk samples has been evaluated in this study, a filtration time of 15 s or more being considered a positive test. Results were compared with those obtained by the WMT in which a column height of 20 mm or more was considered a positive test. Of 364 herd samples tested, 97 were positive to MQG and 9 to WMT, 8 of these latter 9 samples being positive for both tests. Of 181 individual cow samples tested, 75 were positive to MQG and 22 to WMT, all of these latter 22 samples being positive for both tests. High sediment content was considered to be a factor contributing to the large number of positive MQG samples. Also, many of the herd milk samples were old, a factor which probably influenced the WMT results obtained on them. When a yellow material on the disk was used as criterion for a positive test, the MQG was found to agree with the WMT in 16 of the 22 positive WMT results and 175 of the 181 total, individual cow samples.