Absorption of α-tocopheryl acetate is limited in mink kits (Mustela vison) during weaning

Bioavailability of alpha -tocopherol varies with source, dose and duration of supplementation. The effect of source and dose of alpha -tocopherol on response of alpha -tocopherol stereoisomers in plasma and tissues of mink kits during the weaning period was studied. Twelve mink kits were euthanised in CO2 at the beginning of the experiment, and 156 mink kits (12 replicates per treatment group) were randomly assigned to thirteen treatment groups: no added alpha -tocopherol in the feed (0 dose) or four different doses (50, 75, 100 and 150 mg/kg of diet) of RRR-alpha -tocopherol (ALC), RRR-alpha -tocopheryl acetate (ACT) or all-rac-alpha -tocopheryl acetate (SYN). Six mink kits per treatment group were euthanised 3 weeks after initiation of the experiment, and the remaining six were euthanised 6 weeks after initiation of the experiment. The RRR-alpha -tocopherol content in plasma, liver, heart and lungs was affected by interaction between source and dose (P<0.01 for all). The highest RRR--tocopherol content in plasma (13.6 mu g/ml; LS-means for source across dose and week), liver (13.6 mu g/mg), heart (7.6 mu g/mg) and lungs (9.8 mu g/mg) was observed in mink kits fed ALC. The RRR-alpha -tocopherol content in plasma and tissues depended on source and dose interaction and increased linearly with supplementation. In conclusion, the interaction between source and dose reveals a limitation in hydrolysis of ester bond in alpha -tocopheryl acetate in mink kits around weaning as the likely causative explanation for the higher response of ALC at the highest doses. Thus, considerable attention has to be paid to the source of alpha -tocopherol during weaning of mink kits fed a high dose of alpha -tocopherol.

Automated summary

The bioavailability of alpha-tocopherol in mink kits during the weaning period is affected by the source and dose of supplementation. RRR-alpha-tocopherol content in plasma and tissues increases linearly with supplementation and is highest in mink kits fed ALC at the highest doses. The interaction between source and dose may be due to limitations in the hydrolysis of ester bond in alpha-tocopheryl acetate.