Effect of beta-carotene and nucleotide base supplementation on blood composition and immune response in weaned pigs

The effect of synthetic beta-carotene and synthetic nucleotide base on dail y weight gain, feed consumption and certain haematological, biochemical and immunological parameters of piglets were studied in a 3-week experiment. B eginning one week prior to weaning, the diet fed to one experimental group of piglets was supplemented with 10% Rovimix Beta-carotene at 875 mg/kg of diet. Synthetic uracil and adenine (98%, Sigma-Aldrich) were mixed into the diet of the other experimental group at doses of 500 mg/kg of diet for eac h substance. The control group received the basic diet without any suppleme ntation. The changes observed over time in the haematological parameters an d in certain biochemical variables could be regarded as physiological. By d ay 21 of the experiment, beta-carotene supplementation had significantly lo wered the neutrophilic granulocyte percentage and elevated the lymphocyte p ercentage, while in the other two groups a change of opposite tendency occu rred. At the end of the experimental period there was a decrease in plasma vitamin E concentration due to carotene supplementation (control: 6.1 +/- 1 .5, nucleotide: 6.3 +/- 2.5, carotene: 2.3 +/- 1.5 mg/L). Lymphocyte blasto genesis induced by phytohaemagglutinin and concanavalin A increased by 50 a nd 130%, respectively, in the nucleotide group and by 60 and 30%, respectiv ely, in the carotene group, while it did not change in the control group. T he supplements exerted no positive effect on the in vivo cellular immune re sponse.