Effects of positive-pressure pulsation on several characteristics of milk production

A premilking phase of positive-pressure pulsation was evaluated by comparing milk production, persistence, peak milk flow, average milk flow, and several indicators of udder health of two groups of high-producing Holstein cows. Forty-four cows, 21 controls and 23 test animals, completed at least 250 days of lactation. After a premilking wash-up regimen of 25 to 30 s, test cows were given an additional 45 s for positive-pressure pulsation. The group with positive-pressure pulsation maintained significantly more persistence during the last two-thirds of lactation, and this resulted in an 8% relative increase of milk production over controls. There were no differences of udder health between the two groups as measured by number of cases of clinical mastitis or California mastitis test.