1. Cows are Calm and Clean before Milking.

  Cow cleanliness is a major determinant of both milking efficiency and the rate of  intra-mammary infection. It is estimated that cows that enter parlors dirty, double cow prep time and reduce parlor throughput. A French study demonstrated that teat cleanliness is a good predictor of herd average somatic cell count. Environmental pathogens are often the major source of mastitis in herds that have controlled contagious mastitis pathogens. Environmental bacteria (such as E.coli and the environmental streptococci) are often present in organic bedding sources and wet, muddy pens. Management practices that reduce teat end exposure to these organisms will reduce the risk of developing mastitis. Bedding sources that are clean, dry and comfortable will minimize pathogen growth. Inorganic bedding such as sand is often the best choice for reducing pathogen numbers. It is important to recognize that all sand is not created equal and sand must be groomed daily. When rubber filled mattresses are used for cushioning stalls, it is important to adequately bed the stalls to ensure that they remain dry. Further improvements in cow cleanliness can be made through removal of udder hair. It is a good practice to routinely remove udder hair once a month or more often if necessary. Cow handling is an important determinant of milking time efficiency. The release of adrenaline within 30 minutes of milking can interfere with milk letdown and prolong unit on-time. Calm cows enter the milking parlor readily and do not generally defecate in the milking parlor. Personnel working with and moving cows are quiet and gentle. If a number of cows are refusing to enter the parlor or are defecating frequently in the milking parlor, operator and parlor performance should be examined.

2. Cows are Grouped

There are at least two non-nutritional reasons to group cows. Minimizing exposure to cows known to be infected with subclinical mastitis is necessary to control the new infections rate.  In freestall-parlor operations, uninfected cows should be grouped together and milked first. Cows of unknown infection status are milked next and the infected cows are milked last  Sometimes it is necessary to manually sanitize units between cows. To achieve adequate pathogen reduction, units should be rinsed, exposed to 25-50ppm iodine for at least 30 seconds, rinsed and then allowed to dry. In parlor operations, cow grouping is an important element of parlor performance. 

3. A Consistent Premilking Cow Prep is Used

Cows love routine and will reward operators that provide it. Research has documented a 5.5 % increase in lactational milk yield when a standardized milking routine was used compared to a variable milking routine. Achieving consistency can become a challenge when a number of different people are milking cows on an individual dairy each month. With so many different people milking cows, explicit milking routine instruction and training are a necessary component of quality milk production. Pre-milking preparation is a balance between speed (efficiency) and completion of the required steps to clean udders and stimulate milk let down. Milk is stored primarily in the secretory tissue of the udder (the alveoli) and the efficient removal of milk is hastened by coordinating unit attachment with milk letdown. Milk letdown is a combination of both oxytocin (from the pituitary gland) and stimuli from the local nervous system providing feedback to the muscles surrounding the alveoli to release the milk into the ductal and cisternal system for harvest. Selection for high yield and the need for increased cow throughput in parlor operations has led to debate about the necessity of manual stimulation prior to unit attachment. A summary of six studies that compared no stimulation (unit attachment only) to optimal stimulation (at least 20 seconds manual stimulation and unit attachment within 60 seconds) demonstrates the advantage of manual stimulation (Table 4).

Table 4: Summary of six studies on the effect of stimulation on milking.