Effects of β-carotene-enriched dry carrots on β-carotene status and colostral immunoglobulin in β-carotene-deficient Japanese Black cows.

Data from 18 beta-carotene-deficient Japanese Black cows were collected to clarify the effects of feeding beta-carotene-enriched dry carrots on beta-carotene status and colostral immunoglobulin (Ig) in cows. Cows were assigned to control or carrot groups from 3 weeks before the expected calving date to parturition, and supplemental beta-carotene from dry carrots was 138 mg/day in the carrot group. Plasma beta-carotene concentrations in the control and carrot groups at parturition were 95 and 120 mu/dL, and feeding dry carrots slightly improved plasma -carotene at parturition. Feeding dry carrots increased colostral IgA concentrations in cows and tended to increase colostral IgG(1), but colostral IgM, IgG(2), beta-carotene and vitamin A were not affected by the treatment. Feeding dry carrots had no effects on plasma IgG(1), IgA and IgM concentrations in cows, but plasma IgG(1) concentrations decreased rapidly from 3 weeks before the expected calving date to parturition. These results indicate that feeding beta-carotene-enriched dry carrots is effective to enhance colostral IgA and IgG(1) concentrations in beta-carotene-deficient cows.