Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/17/2014
Publication Date: N/A
Citation: Interpretive Summary: d-'-Tocopherol is a highly bioavailable form of dietary vitamin E. Pre-ruminant Holstein calves were fed all-milk diets with varying energy content that were unsupplemented or supplemented with d-a-tocopherol. Supplementation improved plasma vitamin E status, was associated with a reduction in the level of two blood-borne proteins that are normally elevated during inflammation, and tended to increase growth in calves fed for normal growth rates. These results suggest a role for vitamin E in the amelioration of potentially pro-inflammatory state associated with accelerated growth and infectious disease during the pre-ruminant phase of growth.
Technical Abstract: To observe the effects of supplemental dietary d-a-tocopherol in relation to dietary energy on growth and immune status in dairy calves, 32 newborn Holstein bull calves were assigned to 1 of 4 treatments for 5 wks in a 2x2 factorial randomized complete block, split-plot design. Calves received moderate growth (MG) or low growth (LG) all-milk dietary treatments, formulated to support daily gains of 0.5 kg/d or 0.25 kg/d, respectively, per the dietary energy recommendation for milk-fed calves according to the National Research Council’s Nutrient Requirements of Dairy Cattle. Calves in both groups were either injected i.m. with Vital E-A+D® (injectable solution of vitamins E, A, and D) on d 1 and supplemented with Emcelle Tocopherol® (micellized vitamin E) via milk daily (S), or were not supplemented (C) during the study period. Total weight gain of MG calves was greater than that of LG calves and tended to be greater in MG-S calves than in MG-C calves. Calves receiving vitamin supplementation demonstrated greater concentrations of plasma a-tocopherol, retinol, and 25-(OH)-vitamin D than did C calves, whereas MG calves demonstrated lower concentration of plasma a-tocopherol than did LG calves. The apparent increased utilization of a-tocopherol by MG calves was accompanied by a rise in serum haptoglobin, an acute phase protein and indicator of inflammation, especially in MG-C calves. Serum amyoloid A, also an acute phase protein, was not different among groups, but was elevated from baseline in all groups during wks 1 through 3. Plasma IgG1 concentrations were higher in MG-S and LG-S calves than in their non-supplemented dietary counterparts, whereas plasma IgG2, IgA, and IgM concentrations were not different among groups. In summary, dietary supplementation of d-a-tocopherol improved plasma a-tocopherol status and tended to increase growth in MG calves. Vitamin supplementation ameliorated the rise of serum haptoglobin associated with acute inflammation in MG calves, and may have improved passive transfer of maternal antibody. These results indicate a role for a-tocopherol in prevention of pro-inflammatory state associated with accelerated growth and onset of infectious disease. Supported in part by Stuart Products, Inc. Keywords: tocopherol, growth, haptoglobin, dairy calf