Secretory immunoglobulins of the duck (Anas platyrrhynchos domesticus)

Abstract

The profile and functional properties of the immunoglobulins of serum, bile, mucos of trachea and intestine of ducks were studied. The immunoglobulins were separated by salting out using ammonium sulphate. The various fractions of immunoglobulines were further resolved by Sephadex G-200 gel filteration which gave two peaks for serum and tracheal immunoglobulins and a single peak each for bile and intestinal immunoglobulins. The purity of these fractions were checked by immunodiffusion and immunoelectrophoresis. The different fractions obtained were quantified by single radial immunodiffusion. The level of fraction 1 in the bile ranged between 1718 µg/ml and 1959 µg/ml and that of serum, 1718.06 µg/ml to 2442 µg/ml, in the S.typhimurium treated groups. The level of fraction 1 in the NDV treated groups ranged from 1115 µg/ml to 1597.35 µg/ml in bile, and 1597.35 µg/ml to 1959.34 µg/ml in serum. The level of fraction 2 in serum ranged from 1797 µg/ml to 2591 µg/ml in S.typhimurium treated group and 1400 µg/ml to 1797 µg/ml in the NDV treated group. Fraction 2 was not detectable in bile. The antibody response of ducks to a bacterial and viral antigen (anaculture of S.typhimurium and R2B strain of New Castle Disease virus respectively) was assessed. On conducting standard tube agglutination test, the serum, bile and oviduct washings revealed antibody tires against S.typhimurium in inoculated birds ranging between 1:20 and 1:160 in the case of serum; 1:10 and 1:80 in the case of bile and tire less than 1:10 for oviduct washings. No antibody titre could be detected for tracheal and intestinal washings and testicular extracts. The HI titre ranging from 1:32 to 1:128 could be observed for serum, 1:32 to 1:64 for bile and a titre of 1:16 was observed for oviduct washings of ducks parenterally administered with NDV. The tire was relatively low for serum when NDV was administered intranasaly. Intestinal and tracheal washings and testicular extract failed to reveal any HI antibodies.