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

Data from 18 β-carotene-deficient Japanese Black cows were collected to clarify the effects of feeding β-carotene-enriched dry carrots on β-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 β-carotene from dry carrots was 138 mg/day in the carrot group. Plasma β-carotene concentrations in the control and carrot groups at parturition were 95 and 120 μg/dL, and feeding dry carrots slightly improved plasma β-carotene at parturition. Feeding dry carrots increased colostral IgA concentrations in cows and tended to increase colostral IgG1 , but colostral IgM, IgG2 , β-carotene and vitamin A were not affected by the treatment. Feeding dry carrots had no effects on plasma IgG1 , IgA and IgM concentrations in cows, but plasma IgG1 concentrations decreased rapidly from 3 weeks before the expected calving date to parturition. These results indicate that feeding β-carotene-enriched dry carrots is effective to enhance colostral IgA and IgG1 concentrations in β-carotene-deficient cows.