|Rajaraman, Veena - IA STATE UNIV., AMES, IA|
Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 24, 1997
Publication Date: N/A
Interpretive Summary: The newborn calf is highly susceptible to infectious diseases. The immune system plays an important role in defense against infectious diseases. The objective of this study was to evaluate the effects of short-term deprivation of fat-soluble vitamins, which include vitamins A, D, and E, on the immune system of the newborn calf. A second objective was to compare the immune systems of the newborn calf and adult dairy cow. Immune cells from newborn calves were not affected by a short-term deprivation of fat-soluble vitamins A, D, and E. Functional capacities of immune cells from newborn calves, however, were much lower than those of the adults. Immune cells from calves 1-4 days old were the least active in tests evaluating cell function. These results explain the greater susceptibility of younger animals to infectious diseases. A greater understanding of the events occurring in the newborn animals would take us closer to the goal of increasing the competency of the immune system of the newborn calf, resulting in greater health and productivity.
Technical Abstract: Fat-soluble vitamins and their metabolites are known to modulate immune function in a variety of animal species. The objective of the present study was to determine the role of fat-soluble vitamins in colostrum and milk on the development of specific aspects of immune function in the calf during the first week postpartum. During this period, control calves (n=6) were fed normal colostrum and milk, and calves in the treatment group (n=6) were fed skimmed colostrum and skimmed milk supplemented with coconut oil. Treated calves did not experience the progressive increase in concentrations of retinol, beta- carotene, alpha-tocopherol, 1,25-dihydroxyvitamin D, or retinoic acids in serum as observed in control animals. Functional capacities and the cellular composition of blood mononuclear leukocyte populations collected from birth to 7 d postpartum, however, were unaffected by treatment. Serum IgG1 concentrations were also unaffected. Major changes were observed in the function and composition of mononuclear leukocyte populations from all calves during the experimental period, and were likely due to factors unrelated to the concentrations of fat- soluble vitamins in serum. Blood mononuclear leukocyte populations from calves were functionally hyporesponsive and compositionally different from blood mononuclear populations from adult nongravid cows.