Influence of switch level of automatic cluster removers on milking performance and udder health

Abstract

SummaryThe effect of a switch level of 200 or 400 g/min for automatic cluster removers on milking performance and udder health was measured with 71 first lactation cows in their first 36 weeks of lactation and with 64 older cows in their first 12 weeks of lactation. Early removal of the milking unit decreased machine-on time by 0·5 min, increased average milk flow rate slightly, improved teat condition significantly and reduced the change in teat end thickness during milking of first lactation cows. Early removal of the milking unit did not affect milk yield or composition, and the incidence and prevalence of subclinical mastitis were the same in the two groups. Fewer older cows developed clinical mastitis in the group switched at 400 g/min, but this was not significant. It is concluded that the milking unit can be detached at a milk flow rate of 400 instead of 200 g/min without having a negative influence on milk yield. Machine-on time is shortened and teat condition improved, and udder health does not seem to be affected.

Effect of setting a maximum milking time, from peak lactation, on production, milking time and udder health

“…Studies by Rasmussen (1993) and more recently Stewart et al (2002) demonstrated that by raising the threshold setting of the ACR, milking time could be substantially reduced without affecting yield or the incidence and prevalence of subclinical mastitis. Researchers in Australia reported that assigning a maximum milking time resulted in a 34% reduction in the maximum (5), [246][247][248][249][250][251][252]2010 milking time of the slower-milking cows without signifi cant loss of milk yield (Clarke et al 2004).…”

Dynamics of teat-end vacuum during machine milking: types, causes and impacts on teat condition and udder health – a literature review

“…If the teat is not refilled with milk quickly enough after the respective quarter is emptied, the compressed teat is re-opening when the liner opens. However, in this case, it opens via the influx of air or milk from outside the teat instead of a refill with milk from the mammary tissue, thus increasing the risk of cross-contamination and infection (Rasmussen 1993).…”

“…Thus, the time of cluster removal is also a matter of discussion. In an experimental study, Rasmussen (1993) showed that automatic cluster removal at a milk flow level of 400 g/min has no negative influence on milking performance and milk yield but shortens milking duration and reduces stress on the teat tissue. Thus, a longer period of milking at very low milk flow rates or even over-milking in certain quarters towards the end of milking can be avoided by a timely cluster removal.…”

“…There is evidence of increasing sensitivity of teats for developing hyperkeratosis and teat-end eversion towards the end of milking, i.e., the last 0.5 minute before cluster detachment (Rasmussen 1993). Most importantly, there are indications that the risk of new infections, which might also be due to vacuum fluctuations, is at highest when milk flow in the respective quarter has ceased Thompson et al 1978).…”

The measurement of volumetric flow rate milk

“…Taki system powinien mierzyć wypływ mleka z każdej ćwiartki wymienia krowy. Parametry doju będą zmieniać się zależnie od wielkości wypływu mleka [1,8]. Umożliwi to sterowanie procesem doju w obrębie każ-dej ćwiartki i dopasowanie dynamiki doju do cech osobniczych krów.…”