Genetic implications of neonatal immune ontogenesis and challenge for immune response and population health

TY - GEN

T1 - Genetic implications of neonatal immune ontogenesis and challenge for immune response and population health

AU - Ask, Birgitte

AU - van der Waaij, E. H.

AU - van Arendonk, J. A. M.

PY - 2004

Y1 - 2004

N2 - A state-transition model was developed to describe transitions between states of immunity and health among ageclasses (days) in populations of neonate chicks. Immunity was defined as a function of maternal immunity (MI),innate immunity (II), and acquired immunity (AI), while health was defined as susceptible, infected, resistant,recovered or dead. Probability functions were used to describe transitions at immunity-, and health state level.Four scenarios were set up, varying genetic aptitudes for MI (a line with high (HMI) and a line with low MI(LMI)) and time of challenge (1 or 3 weeks of age). HMI expressed a higher antibody (AB) level (MI+AI) thanLMI at 1 week post challenge when challenged at 1 week of age. The ranking of lines would be highlyinfluenced by the correlation between the level of MI and the genetic abilities of the dam for mounting an ABresponse though, and ranking of intermediate lines would be less apparent due to the counteracting effect of MIon AI. Between-line variation and ranking of lines based on differences in health state following challenge at 1week of age was in agreement with that based on differences in AB measurements. The AB level (MI+AI)following challenge at 3 weeks of age was almost equal at any age post challenge. The between-line variation inhealth states, on the other hand, was much larger when challenge was at 3 weeks of age than 1 week of age.In conclusion, the assessment of between-line variation would be most reliable based on challenge at 1 week ofage measuring AB level, corrected for maternal AB, 1 week post challenge.

AB - A state-transition model was developed to describe transitions between states of immunity and health among ageclasses (days) in populations of neonate chicks. Immunity was defined as a function of maternal immunity (MI),innate immunity (II), and acquired immunity (AI), while health was defined as susceptible, infected, resistant,recovered or dead. Probability functions were used to describe transitions at immunity-, and health state level.Four scenarios were set up, varying genetic aptitudes for MI (a line with high (HMI) and a line with low MI(LMI)) and time of challenge (1 or 3 weeks of age). HMI expressed a higher antibody (AB) level (MI+AI) thanLMI at 1 week post challenge when challenged at 1 week of age. The ranking of lines would be highlyinfluenced by the correlation between the level of MI and the genetic abilities of the dam for mounting an ABresponse though, and ranking of intermediate lines would be less apparent due to the counteracting effect of MIon AI. Between-line variation and ranking of lines based on differences in health state following challenge at 1week of age was in agreement with that based on differences in AB measurements. The AB level (MI+AI)following challenge at 3 weeks of age was almost equal at any age post challenge. The between-line variation inhealth states, on the other hand, was much larger when challenge was at 3 weeks of age than 1 week of age.In conclusion, the assessment of between-line variation would be most reliable based on challenge at 1 week ofage measuring AB level, corrected for maternal AB, 1 week post challenge.

M3 - Article in proceedings

BT - Proceedings World's Poultry Congress 2004, Istanbul,Turkey,8-13 June 2004.

T2 - World's Poultry Congress 2004

Y2 - 8 June 2004 through 13 June 2004

ER -