Submitted to: American Dairy Science Association Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 6/1/2004
Publication Date: 7/25/2004
Citation: Foote, M.R., Nonnecke, B.J., Waters, W.R., Palmer, M.V., Fowler, M.A., Miller, B.L., Beitz, D.C. 2004. Dietary protein and energy and the adaptive immune response of milk replacer-fed dairy calves [abstract]. American Dairy Science Association Abstracts. p. 406.
Technical Abstract: We have shown previously that increased protein and energy affect specific aspects of immune function. Effects of enhanced nutrient availability on adaptive immune responses, however, have not been studied. Using a Mycobacterium bovis, BCG sensitization/purified protein derivative (PPD) challenge model, we have shown that neonatal calves, relative to adult cattle, have robust cell-mediated immune responses and weak antibody responses to antigen. The present study examined the effects of increased protein and energy provided by a commercial, intensified milk replacer on the adaptive (i.e. antigen-specific) immune response of the calf. Holstein bull calves were fed a standard (ST, 0.57 kg/d of a 22% CP, 20% F milk replacer, n=11) or intensified (IN, 1.14 kg/d of a 28% CP, 20% F milk replacer, n=11) diet from 1 to 7 wk of age. Calves were vaccinated with BCG at the initiation of the study (i.e. approximately 1 wk of age). Average daily gain was greater (P less than 0.0001) for IN (0.62 kg) than ST (0.29) calves. Liver, thymus, and subcervical lymph nodes from IN calves were heavier (P less than 0.05) than ST calves. Total leukocyte numbers, serum IgG, IgM, and IgA levels and cutaneous reactions to antigen were affected by age but not by nutrition. Mitogen-stimulated blood mononuclear cells (PBMC) from IN calves produced less (P less than 0.05) IFN-gamma and more (P less than 0.05) NO than PBMC from ST calves 5 wk after vaccination, as reported previously. Antigen-induced IFN-gamma and NO production by PBMC, however, were unaffected (P more than 0.05) by nutritional plane. TNF-alpha production of non-stimulated and PPD-stimulated PBMC from IN calves was decreased (P less than 0.05) relative to responses of cells from ST calves 5 wk after vaccination. These results suggest that antigen-specific responses of vaccinated calves are affected minimally by feeding an intensified milk replacer that is available commercially.