Antibody responses to different dosages of sheep red blood cells in lines of chickens selected for high and low antibody response to sheep red blood cells

Temporal patterns of SRBC antibody response after primary and secondary ino culations were measured in White Leghorn males from lines selected 24 gener ations for high (HA) or low (LA) 5-d antibody titers to an i.v. inoculation with 0.1 mL of a 0.25% suspension of SRBC. Primary i.v. inoculations were administered at 50 d of age as 0.1 mt of either 0.025 or 0.25% suspension o f SRBC. Antibody levels of SRBC were measured 3, 5, 7, 9, 11, 13, and 20 d after inoculation. Also, IgG levels were measured on samples obtained 3, 7, 13, and 20 d after inoculation. At 70 d of age, half of the cockerels in e ach line-dosage subclass were given a booster inoculation of 0.1 mL of 0.25 % SRBC. The SRBC antibody was measured 3, 6, 9, and 13 d later in chicks bo th receiving and not receiving the second inoculation. Patterns of antibody response to SRBC dosage differed according to line, resulting in interacti ons of line by dosage by day. Concentrations of IgG were greater for Line H A than for LA at 7 and 11 d after inoculation with SRBC but not at 3 and 20 d. Antibody responses to the booster inoculation differed between lines wi th a dosage effect present for LA but not for HA chicks. The greater anamne stic response observed in LA than in HA chicks is explained in the context of the resource allocation paradigm.