The biological activities of vitamin A acetate and vitamin A palmitate: experiments with chickens.

Abstract

In the first experiment, 250 unsexed day-old chickens were given for 7 days a diet low in vitamin A based on white maize and soya bean meal. Then 100 chickens were given a single dose of 11, 960 IU retinyl acetate or 11, 510 IU retinyl palmitate and 50 were not dosed. After 68 h lots of 10 pooled livers were analysed for vitamin A. The birds given acetate had more vitamin A in the liver and a higher proportion of the dose stored than the palmitate groups, but the differences were not significant. In experiment 2 the sexes were equally divided within groups and the birds were similarly dosed. After 72 h liver vitamin A was significantly higher in groups given the acetate. In experiment 3 male and female chickens were separated and groups of each were given either the acetate or the palmitate ester. Vitamin A was measured in the liver after 3 days and after 4, 6, 7 and 8 weeks. It was significantly more in acetate-treated groups at 3 days and at 4 weeks. Compared with males, females had significantly greater vitamin A stores at 6, 7 and 8 weeks in groups given acetate and at 7 weeks in groups given palmitate. The next experiment was similar, but the basal diet contained 7-5 IU retinyl acetate in dry stabilised form and measurements were continued to 9 and 11 weeks. There was no significant difference in vitamin A stores between sexes or esters, or between dosed and non-dosed groups. Stores of vitamin A rose rapidly during the entire period. In experiments 5 and 6 male broiler chickens were given for 8 weeks the basal diet with 7.5 IU retinyl acetate or palmitate per g. Lots of 3 different body-weight ranges were taken from each treatment and liver vitamin A was measured. No significant effects of treatment on stores or bodyweight were found in either trial. In one trial liver weights were significantly higher in the acetate groups and the combined results showed significantly greater vitamin A stores in groups given acetate.-G. F. H. (Abstract retrieved from CAB Abstracts by CABI’s permission)