Part one of this paper introduced a study evaluating milk quality on 9 Pennsylvania dairy farms using robotic milking systems and characteristics of these farms. This article will focus specifically on teat cleanliness and the ability of the robots to clean teats.
Technical Success of Teat Cleaning
Technical success of teat cleaning in robotic milking systems is defined as having the teat correctly positioned in the cleaning device throughout the entire cleaning process (Hovinen et al., 2005). In the current study 6 farms using Lely robots and 3 farms using Delaval robots were evaluated, these are the two predominant brands of robotic milking systems on Pennsylvania dairy farms. Rotating brushes are used by Lely robots, and a cleaning cup is used in Delaval robots to clean teats.
In the study by Hovinen (2005) cleaning cups achieved technical success on 79.9% of the teat cleaning, and brushes achieved technical success 85.0% of the time. For the current study, technical success was typically over 90% for most farms (Table 1). The exceptions to this were Farms D and H, which achieved a technical success of 53% and 76% for the right front teats. When the low technical success was brought to the farmers’ attention they were able to work with their service providers to remedy the problem. Only Farm E achieved 100% technical success on all four teats during the observation period.
Table 1. Technical success of teat cleaning.
|FARM ID||TECHNICAL SUCCESS, % SUCCESS|
|LEFT FRONT||RIGHT FRONT||LEFT REAR||RIGHT REAR|
Given that under normal conditions the robot misses up to 10% of the teats and under extreme conditions they miss 25 to 50% of teats, good teat cleanliness when the cow enters the robot is important. Teat cleanliness was visually evaluated as cows entered the robot and again following cleaning, but before milking. Teats were scored from 0 (very clean) to 4 (very dirty) at both time points.
In general, between 60 and 80% of teats were very clean (scored 0) and an additional 20% were clean (scored 1) when cows entered the robot (Table 2). Following cleaning this improved to 97 or 98% very clean and 2 to 3% clean on most farms. Even though visually teats looked clean following cleaning, when teats were wiped with an alcohol swab prior to milking unit attachment most swabs still showed that there was some amount of dip, manure, and dirt present on the teat ends at attachment.
Table 2. Distribution of teat cleanliness scores (percentage of teats) before and after the cleaning routine.
|FARM ID||TEAT CLEANLINESS SCORE –
|TEAT CLEANLINESS SCORE –
Conclusions & Recommendations
Data from the current study is still being analyzed to help better understand what management factors contribute to good teat cleanliness and milk quality. In general, Lely brushes and Delaval cleaning cups were able to achieve similar technical success and similar levels of teat cleanliness in the current study. When problems with technical success were brought to the farmers’ attention they were able to remedy the situation. These results demonstrate that robotic milking systems do not eliminate the need for labor and management. Dairy farmers with robots still need to be in the barn on a regular basis to observe the functioning of the robots and cleanliness and health of the cows.
- Hovinen, M., A.-M. Aisla, and S. Pyorala. 2005. Visual detection of technical success and effectiveness of teat cleaning in two automatic milking systems. Journal of Dairy Science 88:3354-3362.