415. Factors affecting the rate of machine milking

Abstract

1. A study was made of the milking of the two hind quarters of four cows by teat cup and by teat cannula at three levels of vacuum and by teat cannula at atmospheric pressure.2. The eight quarters milked at significantly different maximum rates by teat cup but at nearly the same rate through a teat cannula, suggesting that the teat orifice is a very important factor controlling rate of milking.3. The maximum rate of milking by both teat cup and teat cannula increased with increasing level of vacuum from 11 to 20 in. Hg. The rate of increase in the teat-cup milking was greater than in the cannula milking, suggesting that the teat orifice was stretched open at the higher levels of vacuum.4. The average amount of strippings increased at the higher level of vacuum in teat-cup milking, due apparently to teat-cup crawl.

Sources of Variation in Quarter Milk Flow Measures

“…Yields and rates both declined through lactation. Other researchers (1,3,9) have reported that peak and average rates on a whole udder basis declined throughout lactation.…”

“…Milk flow differed between AM and PM milkings. Differences for machine were reported by Smith and Peterson (11), Baxter et al (1), and Schmidt and Van Vleck (9). Schmidt and Van Vleck (9) suggested adjustments of milking rates for pulsation rates, pulsation ratio, and vacuum.…”

“…Variation in total milking time may be an important labor factor in some milking parlors. Rate of flow declines throughout lactation for the whole udder (1,3,10). Smith et al (10) investigated milk flow traits for whole udder and found maximum rate, duration of maximum rate, time to strip, strip time, total time, and average rate were affected by lactation, machine, and interaction of stage of lactation by machine.…”

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

“…The dairy industry promoted the intensive development of accurately working and highly efficient milking machines. Simultaneously, scientists became interested in the investigation of machine milking and its effects on milk yield, milkability, udder health and the quality of milk delivered to the consumer (Baxter et al 1950;Wilson 1963;Bruckmaier 1995;Svennertsen-Sjaunja et al 2003;Moser 2010). The newly established hygienic surveillance of cows and milk caused an increase in detection of udder infections and numerous clinical mastitis cases during the introduction period of machine milking (Wilson 1963).…”

“…This led to the assumption that high vacuum levels and vacuum fluctuations occurring during the milking process had negative effects on teat condition and udder health. From the 1960s to present, one of the main goals of milking equipment engineers and a key subject of research was milking at a more constant teat-end vacuum to achieve fast milk removal while avoiding negative impacts on udder health being caused by the mechanical load on the teats (Baxter et al 1950;Dodd 1963;Wilson 1963;Cowhig 1968;Dodd & Neave 1968;Nyhan 1968;Reinemann et al 2003). The 1960s and 1970s represented the most active period of research related to the effects of pulsation and vacuum including the impacts of irregular and cyclic vacuum fluctuations on milking performance, teat condition and udder health in dairy cows.…”