Effect of dietary β-carotene on the accumulation of β-carotene and vitamin A in plasma and tissues of gilts

Abstract

The absorption of β-carotene in pigs is limited. Nevertheless β-carotene might positively affect reproduction. In this study the absorption and tissue distribution of β-carotene as well as its function as precursor of vitamin A was investigated in gilts that were fed according to one of three dietary treatments: VA (4000 IU vitamin A), VA + VA (4000 IU + 8300 IU) and VA + BC (4000 IU + 100 mg β-carotene per kg diet) for 14 weeks. Only in the VA + BC group was β-carotene detected in plasma (1-8 ng·mL-1), liver, adrenals and corpora lutea, indicating that pigs absorb intac β-carotene at low rates. Liver levels of vitamin A were higher (P < 0.01) at comparable levels in the VA + VA and VA + BC group than in the VA group, indicating a conversion rate of β-carotene to vitamin A of 40 to 1 on the basis of weight for β-carotene at this level (100 mg·kg-1) in the diet. Higher levels of vitamin A in the uterus of the VA + BC group (P < 0.01) as well as the accumulation of β-carotene in adrenals and corpora lutea might reflect some influence of β-carotene on local vitamin A metabolism which might be of importance for reproductive performance in gilts.