MONITORING OF QUARTER HEALTH STATUS BY PERIODIC MILK CONDUCTIVITY MEASUREMENT: A USEFUL MANAGEMENT TOOL IN DAIRY HERDS

摘要

From September 2000 to July 2001 foremilk electrical conductivity (EC) was measured monthly in 3 herds with 46, 60 and 350 milking cows, respectively. The bulk milk somatic cell count was lower than 200,000 cells per ml. A total of 16,606 quarter EC readings were taken on foremilk prior to the udder cleaning routine with a handheld conductometer. Clots and other indicators of abnormal milk were visually detected on a black plate connected to the conductometer. Every three months quarter foremilk was sampled for cyto-bacteriological analysis. A total of 675, 614 and 4,545 samples was collected in herds A, B and C, respectively. In herds A and B, a comparison between California-Mastitis-Test (CMT) and EC was made based on the same milk samples. Results of cyto-bacteriological analyses were classified according to the standards for mastitis classification of the German Veterinarian Society (over 100,000 somatic cells per ml milk and a positive bacteriological result indicates mastitis). As expected, CMT showed more affected quarters than EC measurement, i. e. 89 % and 74 % of all mastitis quarters, respectively. On the other hand, EC measurement has some advantage over CMT: simpler handling, no chemicals needed, and objective numeric results obtained. In addition, EC readings and reading changes per cow and quarter can be graphically evaluated, as well as herd averages. As observed in our investigation, this might be a useful additional management tool especially in larger herds.