Parturient Paresis. III. A Study of Various Blood Constituents at Parturition in Mastectomized Cows

Abstract
Data include analyses for blood serum Ca and Mg, and blood plasma P and fat for 8 parturitions of mastectomized cows for 5 days prepartum, 3 times on the day of parturition, and 5 days postpartum. Comparisons were made with cows calving with intact udders for 5 of these parturitions. The analyses include those blood constituents particularly related to the milk fever syndrome, and a comparison was made between the controls and the mastectomized parturitions uncomplicated by the initiation of lactation. Serum Ca level of mastectomized cows decreased slightly on the day of calving, with a rapid recovery and an increase in postpartum levels above the prepartum level. The control cows showed a characteristic drop from 10.4 mg. % one day prepartum to a low of 8.5 mg. % one day postpartum. Plasma P levels for the 2 groups paralleled each other, both showing a decline at the time of parturition. Serum Mg level of the mastectomized cows remained quite constant, while the control cows showed an average increase from 2.5 mg. % 2 days prepartum to 3.3 mg. % 1-3 hrs. postpartum. Mastectomized cows showed little change in plasma fat levels compared to the control cows, which showed a marked decrease following parturition.