Milking responses of cows given premilking stimulation at four lactational stages.

Milk yield, machine-on time, peak milk flow rate, average milk flow rate, and milk composition were measured in 10 Holstein Friesian cows after receiving no premilking stimulation (i.e., teat cups attached to the udder without premilking washing or teat manipulation) and manual premilking stimulation (30 s udder and teat massage and withdrawal of a few squirts of milk followed by a 30 s delay) at approximately 100, 160, 220, and 280 days postpartum. Milk yield was not different for cows milked with premilking stimulation as compared with cows receiving no premilking stimulation at each stage of the trial. Machine-on time was consistently shorter for cows receiving premilking stimulation. Peak milk flow rate and average flow rate were also uniformly greater in cows receiving premilking stimulation. Milk fat yields were always slightly higher for cows given premilking stimulation compared with those receiving no premilking stimulation. Protein yields did not differ between treatments at any lactational state. Differences in machine-on time and certain milk flow variables are congruent between cows given premilking manual massage and no premilking stimulation during short trials at specific stages of lactation.