EVALUATION OF 50/50 AND 70/30 PULSATION RATIOS IN A LARGE COMMERCIAL DAIRY-HERD

An experiment was conducted in a large commercial dairy milking 1350 Holstein cows in Florida to investigate the effects of 50:50 or 70:30 pulsation ratios on milking parlor performance, milk production, and udder health. The experiment used a reversal design in which the two pulsation ratios were tested over four 2-mo periods in nearly identical double-11 herringbone milking parlors. Analysis of milking parlor performance measures of cows milked per hour, milk harvested per hour. parlor turns per hour, and parlor cycle time revealed a small increase in milking parlor performance for the 70:30 pulsation ratio. Milking with the 70:30 pulsation ratio increased cows milked by 4.1 cows per h, increased milk harvested by 38.3 kg/h, increased parlor turns by .2 turns per hr, and decreased parlor cycle time by .4 min compared with the 50:50 pulsation ratio. Average milk production per cow per milking did not differ between the two ratios. Udder health indicators of clinical mastitis incidence, cows culled for mastitis, or bulk tank SCC were not different because of pulsation ratio.