Adequate oxytocin letdown improves overall parlor performance and is directly related to the procedures and routines utilized in a given parlor. The procedures are those steps that are required to milk one cow. An example would be apply predip, strip teats, dry teats, and finally attach and adjust units. The routine is how groups of cows are milked in the parlor.
There are two main types of oxytocin letdown. Non-conditioned letdown is stimulated by manipulating teats during the udder preparation process. When stimulated by direct contact, nerves in the teats will send a message to the brain which then releases oxytocin from the pituitary gland into the bloodstream. Based on the known physiology of oxytocin letdown, non-conditioned stimulation requires 10 to 12 seconds of teat contact time, followed by full oxytocin expression in the mammary gland at approximately 90 seconds after teats are first touched. The conditioned effect of milk letdown is influenced by what the cow sees, hears, and experiences as she is brought to the parlor, as she enters the parlor and as she standing in the parlor. The more consistent the handling and movement of the cows into the parlor, the better the overall conditioned milk letdown effect. It’s important to remember that if a cow experiences anxiety as she’s moved to the parlor or while she’s in the parlor, it will negatively impact oxytocin letdown. Therefore handling cows in a calm manner and being very consistent in what she experiences during the milking process is extremely important to maximize parlor performance.
There are several routines that are commonly used on dairies. These are dependent on the size of the parlor, the number of milk harvest technicians and the goals of management.
- Group routine - one milk harvest technicians performs all the steps on each cow in a defined group size
- Sequential routine - technicians follow one another in a predetermined manner each performing one or more steps of the udder preparation process
- Territorial routine - this can be a combination of a group or sequential routine where one person is responsible for staying in one area of the parlor.
For maximum consistency, the easiest routine to teach in a parlor is a group routine. By having one technician responsible for each group, timing generally is significantly improved over sequential milking. In sequential milking the most difficult part for technicians to understand is to keep the distance between technicians consistent, to allow maximal oxytocin letdown. Some dairies operate with a group routine in combination with the territory routine. Each technician may milk two or more groups of cows in one section of the parlor and never move to another section of the parlor. Some dairies find this method works very well because they can print a parlor summary report for certain sections of the parlor if they have milk meters with data uploaded to herd a management program such as Dairy Comp 305.
Consistency of all aspects of preparation and routine are extremely important to maximizing parlor performance. Inconsistent application of procedures or the routine will result in longer individual cow milking times and if repeated over time, will result in less milk production per cow.
When producing standard operating procedures for parlors it’s extremely important to very clearly state all aspects of the requirements for milking technicians. Define each step as clearly as possible. For instance, how is the teat predip going to be applied? Dip cups, spraying or foam? Which teats do the technicians start with in the parlor? What you technicians do to more completely clean extremely dirty teats? If stripping is part of the routine, how many streams of milk from each teat? What teats do they start stripping? How are teats dried? In what order are they dried?
Drying teats is the most important aspect of udder preparation if using conventional udder preparation procedures. Teats should be dried with one circular, aggressive motion on each teat, beginning with the teats furthest away from the technician, then proceeding to teats that are closest to the technician. As soon the last teat has been dried with a circular motion, the technician should flip the towel and go back to each teat and make an aggressive pinching action across each teat end in the same order. The goal is to have the teats clean, dry, and stimulated when the technician comes back to attach units.
Attaching units is generally the last step, however it is extremely important to properly adjust the unit so all four teat cups assemblies are hanging straight down on each teat. Proper unit alignment will dramatically reduce liner slips, unit falloffs and reattachments that are required of the milk harvest technicians.
Many dairies are now utilizing mechanical brushes for cleaning and stimulating teats prior to unit attachment. It’s very important to manually flush the mechanical brush after each group of cows to minimize contamination of the brushes. In addition brushes must be changed on a regular basis to ensure that they are effectively cleaning teats. Properly trimming switches on cows will minimize issues with long hair being wrapped around the brushes and rendering them ineffective.
Whatever routines and procedures are used in the parlor, the more consistent these are cow to cow during every milking and from milking technician to milking technician at every milking the better the overall parlor performance will be for the diary. Consistency is the key factor!