Short communication: Effects of changing teatcup removal and vacuum settings on milking efficiency of an automatic milking system

Abstract

The aim of this experiment was to assess strategies to reduce milking time in a pasture-based automatic milking system (AMS). Milking time is an important factor in automatic milking because any reductions in box time can facilitate more milkings per day and hence higher production levels per AMS. This study evaluated 2 end-of-milking criteria treatments (teatcup removal at 30% and 50% of average milk flowrate at the quarter-level), 2 milking system vacuum treatments (static and dynamic, where the milking system vacuum could change during the peak milk flowrate period), and the interaction of these treatment effects on milking time in a Lely Astronaut A4 AMS (Maassluis, the Netherlands). The experiment was carried out at the research facility at Teagasc Moorepark, Cork, Ireland, and used 77 spring-calved cows, which were managed on a grass-based system. Cows were 179 DIM, with an average parity of 3. No significant differences in milk flowrate, milk yield, box time, milking time, or milking interval were found between treatments in this study on cows milked in an AMS on a pasture-based system. Average and peak milk flowrates of 2.15 kg/min and 3.48 kg/min, respectively, were observed during the experiment. Small increases in maximum milk flowrate were detected (+0.09 kg/min) due to the effect of increasing the system vacuum during the peak milk flow period. These small increases in maximum milk flowrate were not sufficient to deliver a significant reduction in milking time or box time. Furthermore, increasing the removal setting from 30% of the average milk flowrate to 50% of the average milk flowrate was not an effective means of reducing box time, because the resultant increase in removal flowrate of 0.12 kg/min was not enough to deliver practical or statistically significant decreases in milking time or box time. Hence, to make significant reductions in milking time, where cows have an average milk flow of 2 kg/min and yield per milking of 10 kg, end-of-milking criteria above 50% of average milk flowrate at the quarter level would be required.

Short communication: Increasing the teatcup removal settings of the last milking quarter did not reduce box time in a pasture-based automatic milking system

“…However, Silva Boloña et al (2020) reported a 30-s reduction in MD Q by increasing the milk flowrate switch-point from 30 to 50% of the quarter rolling AMF for the SQ, but this reduction was in quarter MD rather than udder MD, as reported in the present study. The small differences in milk flowrate at teatcup removal between both treatments appeared to be the main factor affecting the lack of differences on MD, in agreement with data reported by Upton et al (2019) and Silva Boloña et al (2019). The 50% milk flowrate switch-point is the maximum that can be set by the user in this AMS, and it is possible that a higher switch-point might produce a significant effect on MD.…”

“…Additionally, it was estimated that by increasing the milk flowrate switch-point on the quarter with the longest milking duration from 30 to 50% of the quarter's 30-s rolling average milk flowrate, MD of that quarter could be reduced by 30 s (Silva Boloña et al, 2020). However, in the study of Silva Boloña et al (2020), the differences on MD were at the quarter level, which may not necessarily result in a reduction in udder MD or box time (BT), as opposed to the udder level for the Upton et al (2019) and Silva Boloña et al (2019) trials.…”

“…Furthermore, Krawczel et al (2017) used an absolute quarter milk flowrate switch-point in an AMS (0.06 kg/min vs. 0.48 kg/min) and found a significant 54-s reduction in udder MD with no effect on MY or SCC. In the previous studies that used a switch-point of 50% of the quarter's rolling average milk flowrate, an additional criteria was applied by which teatcups were not removed if the milk flowrate of the quarter was above 0.5 kg/min; this affected 13% of milkings as reported by Upton et al (2019) and 25% of the milkings as reported by Silva Boloña et al 2019, limiting the effect of this milk flowrate switch-point. Conversely, results from a simulated teatcup removal setting study showed that quarter MD could be reduced by 24 s by using a quarter milk flowrate switch-point of 50% of that quarter's 30-s rolling average milk flowrate compared with 30% of the quarter's rolling average milk flowrate (Silva Boloña et al, 2020).…”

Milkability differences based on lactation peak and parity in Holstein cattle

“…In the experiment we observed higher milk flow for multiparous cows, which corresponds with the standard milk flows of Holstein cattle (Upton et al, 2019). The period in which the cows reached the highest lactation affected the AMF when early peaking cows had worse values for AMF.…”

Research of some physical and mechanical characteristics of cow’s udder nipples

“…In order to reduce the crawl of two-chamber teat cups on nipples of the mammary gland, the mass of the suspended part of the vacuum milking machine is usually changed [6,7,8].…”