I deally the milking unit should be attached, approximately one minute after preparation, to a fully distended teat. It will then seal better and stay where it belongs. This in turn leads to complete milkout in a shorter period of time. Attaching units too quickly after prepping the teats tends to lead to lower peak flows and longer machine on time. M ilking routines therefore need to be developed that allow thorough preparation and stimulation of the teats followed by unit attachment one minute after this is complete.
Cows are very much creatures of habit and they respond best to consistent routines.
Deviations throw them off because they do not quickly adjust to such changes. M ilkers need to be trained in the basics so that the proper sequence and timing of events is accomplished. Make the routine available in a written format in the language milkers understand. It is also critical that management accept this approach to milking because it is very tempting to speed up the attachment of units with the idea that time is being saved. In fact the time saved at the front end may be offset by lower peak flows and extended machine on-time which is obviously counterproductive.