Effects of [beta]-carotene-enriched dry carrots on [beta]-carotene status and colostral immunoglobulin in [beta]-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 µg/dL, and feeding dry carrots slightly improved plasma [beta]-carotene at parturition. Feeding dry carrots increased colostral IgA concentrations in cows and tended to increase colostral IgG1, but colostral IgM, IgG2, [beta]-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 [beta]-carotene-enriched dry carrots is effective to enhance colostral IgA and IgG1 concentrations in [beta]-carotene-deficient cows.