Immuno-competence data

The exposure of yolk androgens can positively stimulate chick growth and
competitive ability but may negatively affect immunity. It has been
hypothesized that only chicks from immunologically superior fathers can
bear the cost of prenatal exposure to high androgen levels. To test this
hypothesis we paired roosters from two selection lines, one up- and one
down-selected for natural antibodies, with hens from a control line. We
measured yolk testosterone and androstenedione levels, and we injected the
treatment group  of  eggs of each female with
testosterone suspended in sesame oil and the control group with sesame oil
only. We then measured hatching success, growth, and characterised the
humoral and cellular immune responses using three different challenges: a
PHA, an LPS, and an SRBC challenge. We found that the hatching success,
body mass, initial levels of natural antibodies, and the chicks
immunological responses to the three different challenges development were
affected neither by paternal immune-competence nor by treatment. These
results do not support the hypothesis that chicks from low quality fathers
are more sensitive to testosterone exposure during embryonic development
than chicks from high quality fathers.