Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 23, 2014
Publication Date: N/A
Interpretive Summary: The preruminant calf provides an excellent animal model for examining the impact of infection on immune response capacity and vitamin status of the neonate. In the present study, experimental infection of month-old, vitamin D and E replete calves with a “high virulence” strain of bovine viral diarrhea virus (BVDV) elicited a marked elevation in body temperature and rapid reduction in the numbers of blood-borne immune cells. Blood levels of serum amyloid A and haptoglobin, both positive acute phase proteins, increased dramatically post-inoculation. Concurrent with development of the clinical response was a rapid decrease in vitamin D status that was paralleled by an even more pronounced decrease in vitamin E status. Because both vitamins promote optimal immune function, their reduced availability during acute infection may contribute to the severity and duration of the infection.
Technical Abstract: Studies in young animals have shown an association between vitamin deficiencies and increased risk of infectious disease; however, there is a paucity of information regarding the impact of acute infection on the vitamin status of the vitamin-replete neonate. In order to characterize the effects of acute infection on vitamin D and E status of the neonate, six vitamin-replete preruminant Holstein bull calves were experimentally infected with bovine viral diarrhea virus (strain BVDV2-1373). Six additional, mock-inoculated calves served as controls. Sustained pyrexia, leukopenia, and asynchronous increases in serum haptoglobin and serum amyloid A (SAA) characterized the response of calves to infection with BVDV. Infection was also associated with increased serum IFN-', IL-2, and IL-6 concentrations. During the last 8d of the 14d post-inoculation period, serum 25-hydroxyvitamin D and '-tocopherol concentrations in infected calves decreased by 51% and 82%, respectively. The observed inverse association between vitamin D/E status and SAA in infected calves suggests that the infection-induced acute phase response contributed to the reduced vitamin status of these animals. Additional studies are necessary to determine if the negative effect of infection on status are unique to this specific infection model or is representative of preruminant calf’s response to acute infection. Studies are also needed to characterize mechanisms underlying infection-related changes in vitamin D and E status and to determine whether additional vitamin D and/or E supplementation during an acute infection diminishes disease severity and duration in the young animal.