The vitamin A activity of beta-carotene in growing pigs. 1. Effect of a supplementation of a grain soya bean meal diet with vitamin A or beta-carotene on the liver vitamin A storage.
In 3 experiments with a total of 113 growing pigs, supplements of 1,000 to 9,000 IU vitamin A or 2 to 100 mg beta-carotene to vitamin A and beta-carotene free grains soyabean-meal-diets were tested. The liver samples were taken by biopsy or after slaughtering. The error of biopsy sampling was defined in preliminary experiments. The initial liver vitamin A depots were checked by slaughtering of 5 piglets of each group. The vitamin A content was analyzed by the anhydromethod or fluorometrically. In all 3 experiments, the different vitamin or provitamin intake did not influence feed intake and growth at any time. Highly significant linear relations were found between the intake of vitamin A or beta-carotene and the storage in the liver. Due to the higher relative liver weight, younger animals had a lower vitamin A concentration in this organ. Related to the tested beta-carotene dose of 2, 4, 8, 50 and 100 mg/kg feed, a vitamin A activity of 360, 320, 290, 130 and 80 micrograms retinol equivalents per mg beta-carotene was found. The conversion of beta-carotene into vitamin A decreases inversely to the beta-carotene intake. The vitamin A activity of synthetic beta-carotene which is higher than the beta-carotene analyzed in feedstuffs is discussed.
Karl-Marx-Universität Leipzig, School of Animal Production and Veterinary Medicine, Department of Animal Nutrition-Chemistry, Jena, GDR.
F
F
Schoene
H
H
Luedke
A
A
Hennig
W
W
Ochrimenko
P
P
Moeckel
D
D
Geinitz
D000821:Animal Feed; D000818:Animals; D001835:Body Weight; D002338:Carotenoids / Q000008:administration & dosage / Q000378:metabolism*; D004435:Eating; D008099:Liver / Q000378:metabolism*; D011810:Quinoxalines / Q000008:administration & dosage*; D013025:Glycine max; D013552:Swine / Q000254:growth & development / Q000378:metabolism*; D014801:Vitamin A / Q000008:administration & dosage / Q000378:metabolism*; D019207:beta Carotene
D011810:Quinoxalines; D019207:beta Carotene; D014801:Vitamin A; D002338:Carotenoids; C013168:olaquindox