Antibody responses of undernourished sinclairs(S-1) miniature swine

1.Sinclair(S-1) miniature swine, 9 weeks of age, were divided into 2 groups and ad libitum fed diets containing 16 or 4% protein. After 0, 4, 8, 12, 16, 20 or 24 weeks, 2 males and 2 females from each group were injected with a suspension of bovine serum albumin, Salmonella typhosa "H" antigen and influenza virus. Blood samples were taken periodically and serum antibody titers were determined by standard methods. All animals were sacrificed 8 weeks after primary antigenic stimulation. At 120 hours before sacrifice each animal was injected subcutaneously with sheep erythrocytes; a regional lymph node was removed at necropsy and tested for antibody producing cells.2.There was no difference in the antibody responses of the 2 dietary groups tested after 0, 4 or 8 weeks. After 12 or 16 weeks on test, the appearance of serum antibody was delayed and maximum antibody titers were attained later in undernourished swine. Serum antibody not only appeared later in undernourished swine tested after 20 or 24 weeks, but it also failed to attain the levels reached in corresponding control animals. Mercaptoethanol-sensitive antibody was affected more than mercaptoethanol-resistant antibody. Also, there was a decrease in the number of antibody producing cells obtained from the lymph nodes of undernourished swine.