Influence of vitamin A supplementation in milk on growth, health, concentrations of vitamins in plasma, and immune parameters of calves.
Seventy-seven Holstein calves were used to determine effects of vitamin A supplementation (0, 15,000, or 30,000 IU/d) of milk fed to calves through 6 wk of age. Effects of gender of calves and parity of dams also were considered. Supplementation with vitamin A did not affect retinol concentrations in plasma; however, calves fed milk containing supplemental vitamin A had decreased alpha-tocopherol concentrations in plasma at 6 wk compared with the concentrations in plasma of calves that were fed milk without supplemental vitamin A. Growth, serum protein, serum immunoglobulin (Ig) M and IgG, leukocyte proportions, and weekly fecal scores were not affected by vitamin A supplementation. Calves that scoured were fed milk supplemented with an additional 0 or 30,000 IU/d of vitamin A. Supplementation with an additional 30,000 IU/d when calves were scouring increased treatment days. Female calves had lower body measurements (weight, length, and height) at birth and greater fecal scores for wk 2 and 3 than did male calves. Gender did not affect serum protein, IgM, or IgG; however, female calves had higher percentages of monocytes and lower percentages of T cells than did male calves. At 6 wk, female calves also had higher percentages of B cells than did male calves. These data indicate that ratios of vitamins A and E should be considered in dietary formulations for calves. Also, additional vitamin A provided by some scour treatments could be detrimental to calves that are already receive vitamin A supplementation.
Franklin
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Dairy Science Department, South Dakota State University, Brookings 57007, USA.
Sorenson
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Hammell
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D000818:Animals; D001699:Biometry; D001798:Blood Proteins / Q000378:metabolism; D002417:Cattle / Q000254:growth & development / Q000276:immunology / Q000502:physiology*; D019587:Dietary Supplements; D005243:Feces; D005260:Female; D007109:Immunity; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D018655:Lymphocyte Count; D008297:Male; D008892:Milk; D014801:Vitamin A / Q000008:administration & dosage* / Q000097:blood; D014810:Vitamin E / Q000097:blood; D014815:Vitamins / Q000097:blood*
D001798:Blood Proteins; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D014815:Vitamins; D014801:Vitamin A; D014810:Vitamin E