The accumulation of alpha- and beta-carotene in serum and tissues of preruminant calves fed raw and steamed carrot slurries.

The preruminant calf model was used to evaluate the effects of mild heat treatment on the serum and tissue accumulation of alpha- and beta-carotene from carrots. Twenty-four 1-wk-old Holstein male calves were assigned to one of four groups and fed a milk replacer diet. Negative control animals received no additional supplement. The three remaining groups received an additional 20 mg beta-carotene/d from either water-soluble beadlets, homogenized raw carrots or homogenized steamed carrots. Serum samples were obtained daily, and calves were killed after 7 d and samples of serum, liver and adrenal collected. Tissue and serum alpha- and beta-carotene concentrations were not significantly higher in steamed carrot-fed animals than in raw carrot-fed animals. The molar ratios of beta-carotene to alpha-carotene in both raw carrot-fed and steamed carrot-fed groups were highest in adrenal tissues, intermediate in serum and lowest in the diets. None of these differences were statistically significant. When the serum, liver and adrenal beta-carotene data were pooled, the mean relative accumulation of beta-carotene, expressed as a percentage of the mean response of calves receiving water-soluble beadlets, was 46.8% for calves fed raw carrots and 74.0% for calves fed steamed carrots. These results suggest a small enhancing effect of mild heat treatment of carrots on the serum and tissue accumulation of carotenoids.