Purdue researchers investigated the effects of milking heifers before calving on milk production and heifer health. Milking began 21 days before the expected calving date for half of the heifers in the trial and at calving for the remaining heifers. Heifers were fed a single TMR and allowed ad lib consumption. One day after calving, premilked heifers produced 42.5 pounds of milk compared to 15.9 for control heifers. Production differences decreased steadily, and by 14 days after calving, there was no difference between the two groups. Complete lactation milk production and production persistency were similar between the two groups. Somatic cell count during the first month after calving and throughout first lactation was lower in heifers milked before calving. Udder edema was also reduced in premilked heifers. However, the premilked heifers had more quarters infected with Strep. uberis at calving than control heifers.
Because all other measures of udder health were improved, the increase in infections of an opportunistic environmental pathogen could be due to increased exposure in the premilked heifers compared to the control heifers, not to poorer udder health.
The authors concluded that prepartum milking has several beneficial effects. They also suggested that increasing diet energy density at the time milking begins may be needed to realize the full potential of milking heifers before calving. This research was published in the May 2007 issue of the Journal of Dairy Science.
Source: Dairy Calf and Heifer Association