Browsing by Subject "Melken"

Now showing 1 - 2 of 2

Investigating dairy cow welfare by optimizing pulsation cycles and improving activity measurements during milking from a technical perspective
(2016) Blümel, Franziska Elisabeth; Schick, Matthias
During machine milking, farmers often encounter milking problems even though milking machine constructions generally comply with the required international standards. The first aim of this thesis was to investigate the effect of two different durations of the closing and closed phase (c- and d-phase, respectively) on physical processes in the milking cluster. The second aim was to examine the effect of these c- and d-phases on milk removal and hind-leg activity. It was hypothesized that a prolonged c-phase (i.e. slower liner closing) might be gentler and more comfortable for the dairy cow than a short c-phase (i.e. faster liner closing). Consequently, this would lead to optimized milk removal and calmer dairy cow behavior in the milking parlor. Therefore, dairy cows were confronted randomly with two types of pulsation chamber cycles (Treatments A and B) for 12 milkings. The treatments differed in the durations of c- and d-phases. In Treatment A, the c-phase lasted 70 ms and the d-phase 330 ms, whereas in Treatment B, the c-phase lasted 130 ms and the d-phase 270 ms. Using a vacuum measuring device (MT52, BEPRO AG, Güttingen, Switzerland), measurements were taken during milking proceedings. Milk flow characteristics were recorded using milk flow meters (LactoCorder®, WMB AG, Balgach, Switzerland). Hind-leg activity was recorded during milking using accelerometers attached on the hind-legs (RumiWatch® pedometer, ITIN+HOCH GmbH, Liestal, Switzerland). Treatment B showed the following effects on parameters measured in the milking cluster compared with Treatment A: -Durations of open liner were on average 26.2 ms longer. -Durations of closing liner were on average 23.4 ms longer. -Pressure sum was on average 1 kPa lower. Treatment B showed the following effects on milk flow and hind-leg activity compared with Treatment A: -Cows produced 0.21 kg higher total milk yield. -Peak flow rate was 1.04 kg/min higher. This thesis showed that c-phase durations influence physical processes in the milking cluster and milk flow characteristics. A prolonged c-phase is not only beneficial for dairy cow’s health but also from an economic point of view. Statements regarding welfare improvements are rather difficult to make. In addition to the first and second aim of this thesis, the third aim was to examine the correlations of hind-leg activity with accelerometers attached to the hind-leg and to the milking cluster with direct observations. As restlessness during milking is considered as an important parameter for impairments of dairy cow welfare, a standardized measuring procedure for this behavior may be severe for detection of deficient milking conditions. It was assumed that the milking cluster is set in motion as hind-legs of dairy cows move, because the milking cluster is freely suspended on the cow’s udder. Therefore, an accelerometer attached to the milking cluster may measure the hind-leg activity of the dairy cow indirectly. This method could replace laborious attaching of accelerometers on the hind-legs of dairy cows and provide a standardized on-line measuring procedure. Therefore, measurements with accelerometers on hind-legs of dairy cows and on the milking cluster were taken once during morning and evening milkings for every cow. In addition, direct observations of dairy cows’ motion behavior during milking were made. The differentiation of hind-leg activity took place between active phases and inactive phases. Data from morning milkings were used to create an algorithm to validate data automatically from evening milkings. The correlation measurements of hind-leg activity were as follows: - The algorithm is defined as the number of observations using mean values + standard deviation + 0.2 m/s2. -Correlation “visually counted number of active phases from graphs” with “number of observations calculated with the algorithm from the milking cluster” was 97 % (morning milkings). -Correlation “number of active phases recorded with milking cluster using the algorithm” with “number of active phases using direct observations” was 74 %. -Correlation “number of active phases recorded with the hind-leg using the algorithm” with “number of active phases using direct observations” was 91 %. It was possible to develop a hind-leg activity measuring method, without attaching accelerometers on the hind-legs of dairy cows. With this novel method, costs and labor can be minimized and objective examination of animal behavior can be guaranteed. In a next step, it can be implemented in the milking parlor or in the automatic milking device as a diagnostic tool providing valuable information to the farmer and consultant in a management program.
Making milking easier : reducing physical strain of parlor workers during milking cluster attachment
(2017) Cockburn, Marianne; Schick, Matthias
Milking personnel have been affected by musculoskeletal disorders for many years. In parlor workers the shoulders, wrists and lower back are most affected. As the procedure of milking cluster attachment has been reported to be the most strenuous during milking, we took a three- step approach to reduce the physical strain of this task. In the first step, we used the computer-assisted recording and long-term analysis system (CUELA) to record flexion angles of multiple joints during milking. The posture of 30 milkers was evaluated on 15 farms. Milking parlor types evaluated included the Herringbone 30°, the Herringbone 50°, and the Parallel as well as the Rotary parlor. The 5th, 50th and 95th percentiles of the data recordings were classified against ISO Norms and it was found that joint flexion angles were concerning. The statistical analysis revealed a significant interaction between milking parlor type and a working height coefficient, which reflected the ratio between the subject’s height and the effective udder height (udder height + depth of pit). By using model predictions, we calculated working height coefficients that could improve joint flexion angles. These working height coefficients were calculated for each parlor type and used within the newly developed “milking health formula” to calculate the ideal depth of pit, under the consideration of the milker’s height, milking parlor type and udder height. As the working heights recommended within the milking health formula were relatively low for all parlor types, and the recommendations made for the Herringbone 30° were broad, we aimed to further validate our findings by using surface electromyography to monitor muscle contraction intensities of 16 milkers (nine females, seven males). The second step of this thesis was performed in a laboratory setting where the milking cluster was attached to an artificial udder. It was important to ensure that the milking health formula enabled a consistent setting of working heights for milkers of different body heights, as well as ensuring that lower working heights reduced muscle contraction intensities of the upper limb and shoulder muscles. The results showed that lower working heights decreased muscle contraction intensities of the shoulder muscles, but not of the lower and upper arms. Further, since the subjects body height had no effect on muscle contraction intensities, it can be concluded that the formula offers an effective way to set comparable working heights for milkers of different body heights. Posture of milkers is not only affected by working heights, but also by the horizontal reaching distance between the milker and the cows’ udder. It has recently been assumed that milking stall dimensions are currently too small for dairy cows and that they should be increased to ensure their welfare. This could however increase the reaching distance between the udder and the cow and thus negatively affect ergonomics. In the third step of the thesis, we therefore used surface electromyography, in both a Herringbone 30° and a Side by Side milking parlor, to investigate the effect of increased milking stall dimensions on muscle contraction intensities of the upper limb and shoulder muscles during milking. Nine male subjects milked 30 cows twice per parlor type, where the milking stall dimensions were large on one side of the milking parlor and standard sized on the other. Milking stall dimensions had no effect on muscular contraction intensities in the Side by Side parlor and a controversial effect in the Herringbone 30° parlor. The contraction intensities in the right lower and upper arm were higher when cows were milked in standard sized milking stalls, but were higher in the left upper arm when cows were milked in large milking stalls. The effect of milking stall dimensions on the work environment should therefore be further investigated. In conclusion, the current project has developed a method to calculate beneficial working heights for a variety of milking parlor types. These derived recommendations have been further validated and it was shown that lower working heights reduced muscular load of the shoulder muscles.