Cows and heifers should be moved from winter grounds to calving grounds 2–3 wk before calving season begins. They should be sorted into groups based on estimated calving date. This date can be determined at the time of pregnancy examination, when cows and heifers are grouped based on estimated duration of gestation. Separation of the herd into groups allows more concentrated observation of a smaller number of cows or heifers that are more likely to calve and potentially need help.
Cows and heifers should be observed to ensure they accept and mother their calves. Heifers especially are at risk of calf rejection, which increases the risk of calf disease. If heifers do not accept their calves and allow nursing within a short time, they should be brought into the calving barn and restrained to allow the calf to suck. Heifers that experience dystocia and human assistance are at increased risk of rejecting their calves. Cows or heifers that experience difficulty in calving or mothering should be moved to the calving barn for assistance and monitoring. Pairs entering the calving barn are at increased risk of disease because of dystocia, mismothering, hypothermia, and exposure to a higher population density. Once a pair enters the calving barn, they should not go to the general nursery pasture but to a separate high-risk nursery. Calves in the high-risk nursery can be monitored more closely for morbidity and treated promptly. Segregation of these high-risk calves also avoids exposure of the rest of the herd. Consideration should be given to management of infectious diseases such as Johnes disease by segregating higher-risk cows from lower-risk cows throughout this calving management period.
Once cows or heifers have calved, the pair should be moved out of the calving area to a nursery pasture within 24 hr. When the pair has bonded and passive transfer has occurred, movement to a nursery with decreased population density minimizes infection rates. Sick calves in the healthy nursery pasture should be removed and brought to the barn for treatment if necessary and placed in a morbidity nursery. Infectious agents can multiply in clinically ill calves and cause high levels of environmental contamination. The morbidity nursery may be combined with the high-risk nursery, but this increases exposure of the high-risk calves to pathogens. Ill calves should not be returned to the general nursery area. Treatment equipment should be disinfected thoroughly between calves to avoid transfer of infectious agents from calf to calf.