Prepartum Milking. I. The Effect of Prepartum Milking on Some Blood Constituents of the Cow

Prepartum milking has been proposed for reducing the incidence of milk fever and decreasing mammary and umbilical edema (4, 20). However, Smith and Blosser ( This study was undertaken to determine quantitatively the effect of prepartum milking upon the changes occurring at parturition in total blood hemoglobin, total blood serum calcium, total blood serum inorganic phosphorous, and plasma carotene and vitamin A, and on mammary and umbilical edema. Secondarily these factors were studied in relation to two dietary regimes. EXPEEIMENTAL Animals. A total of 43 cows of the Ayrshire, Guernsey, Holstein and Jersey breeds in the University of Connecticut herd which calved from November, 1947, through December, 1948, were used in the experiment. They were divided into four experimental groups which were equalized insofar as possible in respect to breed, age, number of previous lactations, anticipated length of dry period, health, ancestry and previous dietary history. Groups 1-A and 1-B were not milked prepartum, Group 1-A receiving the basal ration alone, and 1-B the basal ration + 1 million USP units of vitamin A daily for 30 days prior to the calculated parturition date. Groups 2-A and 2-B were milked prepartum, Group 2-A receiving the basal ration and Group 2-B the basal ration plus the vitamin A supplement.