Prepartum Milking. II. The Effect of Prepartum Milking on the Carotene and Vitamin A and Proximate Composition of Colostrum

Open Access
Publisher Website
Google Scholar
Abstract
The effect of prepartum milking for 10 days prior to the calculated parturition date on the carotene and vit. A, and proximate composition of colostrum was studied in 44 cows. In addition, the changes in the carotene and vit. A content of both pre-milk and colostrum were studied in 14 of these cows milked for 10 or more days prepartum. Secondarily, the effect of feeding 1 million U.S.P. units of vit. A daily for 30 days prior to the calculated parturition date was measured. Prepartum milking resulted in significant decreases in the carotene, vit. A, protein, and ash contents, and in specific gravity and significant increases in the lactose content of the colostrum of the first 6 milkings postpartum. Both the carotene and vit. A content of pre-milk and of colostrum decreased with successive milkings in cows milked for 10 or more days prepartum. Parturition caused a decrease in this negative trend. The prepartum feeding of supplementary vit. A resulted in significant increases in the vit. A content of both pre-milk and colostrum, and decreased the carotene content of colostrum.