Antibody transmitting ability of hens from lines of chickens differing in response to SRBC antigen.

1. Hens from White Leghorn lines selected for high (HA) or low (LA) antibody response to sheep red blood cells (SRBC) were inoculated with 0.1 ml of either 0.25% or 2.50% SRBC suspension. Eggs laid over the next 15 d were grouped into 5, 3-d collection periods and incubated. Maternal antibody titres were determined in chicks at hatch and 7 d after hatch. 2. In a subsequent experiment, hens of the 2 lines were inoculated with 0.1 ml of 2.50% suspension of SRBC, and eggs laid on days 10 to 13 after inoculation were incubated. Maternal antibody titres were determined in 15 and 18-d embryos as well as in chicks at 0, 5, 10, 15, 20, and 25 d after hatch. 3. Dosage of SRBC had no effect on the antibody titres in line HA; however, the higher dosage elicited greater antibody titres than the lower dosage in line LA. 4. Maternal antibodies were detected earlier in chicks of line HA (eggs laid on days 7 to 9) than those of line LA (eggs laid on days 10 to 12) regardless of dosage administered to the hens. 5. In both lines, antibodies specific to SRBC were observed on day 15 of incubation, with the frequency of responders greatest at hatch. The high frequency of HA responders was maintained for 15 d after hatch, whereas there was an immediate decline with age in LA responders. 6. It was concluded that lines HA and LA have diverged in the pattern of maternal antibody levels as a result of the divergent selection for antibody response to SRBC.