Liner Wall Movement and Vacuum Measured by Data Acquisition

Spencer, S.B.; Jones, Lewis

doi:10.3168/jds.s0022-0302(00)74976-9

Cited by 6 publications

(5 citation statements)

References 8 publications

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“…As a consequence, a drop of the claw vacuum during milking may not only reduce milking performance through reduced efficiency of milk removal (Rasmussen and Madsen, 2000) but can also compromise the teat condition due to an impaired liner closure and reduced pressure of the liner on the teat and hence a reduced massage effect of the closed liner on the teat (Hamann et al, 1993). The effect of low teat end vacuum on the liner movement within each pulsation cycle leads to a prolonged liner-open phase because the liner opens earlier during the evacuation phase of the pulsation chamber and closes later when the pulsation chamber is ventilated (Spencer and Jones, 2000). In addition, a drop of the claw vacuum may increase the probability of liner slips because the adhesion of the liner to the teat is reduced (Baxter et al, 1950;Stewart and Schultz, 1958;Rasmussen and Madsen, 2000;Besier et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

Vacuum levels and milk-flow-dependent vacuum drops affect machine milking performance and teat condition in dairy cows

Besier

Bruckmaier

2016

Journal of Dairy Science

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Different levels of claw vacuum during machine milking may influence milking performance and teat condition. The claw vacuum acts on the teat and is responsible for removal and transport of milk but is also causing potential effects on the teat tissue. In the absence of milk flow, the claw vacuum is similar as the system vacuum. During milk flow, the claw vacuum drops to lower levels depending on lifting height and tube length and diameter, which may influence milking performance and the mechanical load on the teat tissue. The goal of the present study was to investigate the effects of high system vacuum and extremely low claw vacuum during milk flow on milking performance and teat condition after milking recorded by ultrasound. Treatments were control (treatment 1) with a system vacuum of 42 and a minimum claw vacuum during milk flow of 33 kPa; treatment 2 representing a system vacuum of 50 kPa, with a minimum claw vacuum almost similar as treatment 1 (34 kPa); and treatment 3 with the same system vacuum as treatment 1 but a claw vacuum drop during milk flow down to 24 kPa. Total milk yield was similar in all treatments, but strip yield was lower in treatment 3 than in the other treatments. Milk flow was similar in treatment 1 and treatment 2, but was reduced in treatment 3, thus causing a prolonged milking time in treatment 3. Teat wall thickness was increased and teat cistern diameter was decreased in treatment 2 as compared with the other treatments. The results demonstrate that the minimum claw vacuum had the main influence on milking performance independent of the level of the system vacuum and related vacuum drops and a low minimum claw vacuum caused low milk flow and long milking times. Teat condition at the end of milking, however, was mainly dependent on the system vacuum, and the load on the teat tissue was obviously increased at a system vacuum of 50 kPa. This effect was obviously occurring toward the end of milking when milk flow decreased and hence the milk flow dependent vacuum drop disappeared. Therefore, an early cluster detachment should be considered to avoid an increased effect on the teat tissue. Estimates of simulated early detachment levels in the present study of up to 1,000g/min lead to the assumption of minimal milk loss at simultaneously shorter machine-on time through the avoidance of lowest milk flow at the end of milking.

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Section: Introductionmentioning

confidence: 99%

Vacuum levels and milk-flow-dependent vacuum drops affect machine milking performance and teat condition in dairy cows

Besier

Bruckmaier

2016

Journal of Dairy Science

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“…Teat liners should support teat integrity and massage the teat with a compressive load (Spencer & Jones, 2000). Liner design is often a series of compromises.…”

Section: Resultsmentioning

confidence: 99%

“…Low claw vacuum causes liner movement within each pulsation cycle, which leads to a prolonged lineropen phase. This means that the liner opens earlier during the evacuation phase of the pulsation chamber (aphase) and closes later when the pulsation chamber is ventilated (c-phase) (Spencer & Jones, 2000). In addition, a drop in the claw vacuum may increase the probability of liner slips because the adhesion of the liner to the teat is reduced (Spencer, 2011;Besier & Bruckmaier, 2016;Rasmussen & Madsen, 2000).…”

Section: Resultsmentioning

confidence: 99%

Effects of milking machine settings and teat liners on bovine udder health

Vermaak¹,

Petzer²,

Karzis³

2023

SA J. An. Sci.

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The purpose of milking machines is to harvest milk at an optimum speed while maintaining cow comfort and preserving teat defence mechanisms against the invasion of mastitis pathogens, thus making machine settings critical in dairy herds. The various settings and combinations for milking machines were reviewed to enable operators to optimize them to preserve teat canal integrity and minimize mastitis. All databases of Web of Science and relevant websites were used to document machine settings and teat liners. All vacuum levels in milking systems need to be monitored. In addition, liners, milk yield, and automated cluster removal switch-point settings need to be regarded as bearing a risk of teat damage. They affect milking speed and vacuum levels at total, peak, and over-milking. An equilibrium should be reached between optimal milking speed and risk of teat damage. An increased switch-point setting shortens milking time and decreases overmilking and claw vacuum to preserve teat-canal integrity. Analysis of milk flow dynamics with a VaDia instrument highlights opportunities to improve milking protocols and equipment functions that align with the physiology of the cow. This knowledge can be applied on individual farms, in which herd milk yield, parlour layout, milking machine system, parlour management, and economics should be considered to obtain a balance between milking efficiency, udder health, and cow comfort. Standards for switch-point settings were identified in this review.

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“…Therefore, methods to detect the pressure between the teat and a collapsing liner have been developed. One such method frequently used in literature is the calculation of the touch point [3,4,5,6,7,8], the residual vacuum available for massage [4,9,10], the liner compression [3,4,8,9], the over-pressure [4,10,11], and the true milk:rest ratio [4,10]. In several studies, the usability of pressure sensors to measure the pressure between a teat and the teat cup liner was tested.…”

Section: Introductionmentioning

confidence: 99%

The Usability of a Pressure-Indicating Film to Measure the Teat Load Caused by a Collapsing Liner

Demba

Elsholz

Ammon

et al. 2016

Sensors

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Prevention of damage to the teat and mastitis requires determination of the teat load caused by a collapsing liner. The aim of this study was to test a pressure-indicating film designed to measure the pressure between a collapsing liner and artificial teats. The Ultra Super Low and the Extreme Low pressure-indicating films were tested on two types of artificial teat. The experiments were performed with a conventional milking cluster equipped with round silicone liners. For each teat and film type, 30 repetitions were performed. Each repetition was performed with a new piece of film. Kruskal-Wallis tests were performed to detect differences between the pressure values for the different teats. The area of regions where pressure-indication color developed was calculated to determine the most suitable film type. Both film types measured the pressure applied to both artificial teats by the teat cup liner. Thus, the pressure-indicating films can be used to measure the pressure between a collapsing liner and an artificial teat. Based on the results of the present investigation, a pressure-indicating film with the measurement ranges of both film types combined would be an optimal tool to measure the overall pressure between an artificial teat and a collapsing liner.

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Liner Wall Movement and Vacuum Measured by Data Acquisition

Cited by 6 publications

References 8 publications

Vacuum levels and milk-flow-dependent vacuum drops affect machine milking performance and teat condition in dairy cows

Vacuum levels and milk-flow-dependent vacuum drops affect machine milking performance and teat condition in dairy cows

Effects of milking machine settings and teat liners on bovine udder health

The Usability of a Pressure-Indicating Film to Measure the Teat Load Caused by a Collapsing Liner

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