The effects of quarter-individual milking in conventional milking parlours on the somatic cell count and udder health of dairy cows.

The objective of this study was to examine the quarter health status of quarter-individually and conventionally milked cows. The MultiLactor®, a quarter-individual milking system (MULTI), has single guided tubes which provide milking on the quarter level with a low system vacuum level (37 kPa), sequential pulsation and periodic air inlet. The conventional milking system (CON) was equipped with a milking cluster where the system vacuum level was adjusted to 40 kPa. A total of 84 German Holstein cows, randomly divided into two groups, were included in the study. Over a period of 32 trial weeks, quarter foremilk samples were taken every week to determine somatic cell count (SCC). Bacteriological examinations and udder palpation were conducted at three different times. During the trial period, median SCC of quarter foremilk samples in both groups did not exceed the threshold value of 100,000 cells/ml. The results of the F test showed that the milking system (P = 0.0587) and days in milk (DIM) (P = 0.8066) had no significant effects on the quarter health status. On the other hand, lactation (P = 0.0396), quarter health status in the previous week (P < 0.0001) and trial week (P = 0.0061) affected quarter health status significantly. The estimated probabilities of the occurrence of a suspicious quarter (SCC > 100,000 cells/ml) were 19.97% (CON) and 31.72% (MULTI). However, the test of differences in the Least Square Means (LSM) showed no significant differences (P = 0.0585) between CON and MULTI. The estimated probability of quarters becoming suspicious during the first lactation was 12.51% for both groups. With an increasing number of lactation, the probability of a quarter becoming suspicious clearly increased (2nd lactation: 32.73% and 3rd lactation: 36.19%). The results also showed that the percentage of quarters with bacteriological findings revealed a stronger increase over time for MULTI than for CON.

Development of a control system for the teat-end vacuum in individual quarter milking systems.

Progress in sensor technique and electronics has led to a decrease in the costs of electronic and sensor components. In modern dairy farms, having udders in good condition, a lower frequency of udder disease and an extended service life of dairy cows will help ensure competitiveness. The objective of this study was to develop a teat-end vacuum control system with individual quarter actor reaction. Based on a review of the literature, this system is assumed to protect the teat tissue. It reduces the mean teat-end vacuum in the maximum vacuum phase (b) to a level of 20 kPa at a flow rate of 0.25 L/min per quarter. At flow rates higher than 1.50 L/min per quarter, the teat-end vacuum can be controlled to a level of 30 kPa, because in this case it is desirable to have a higher vacuum for the transportation of the milk to the receiver. With this system it is possible for the first time to supply the teat end with low vacuum at low flow rates and with higher vacuum at increasing flow rates in a continuous process with a three second reaction-rate on individual quarter level. This system is completely automated.