Submitted to: Avian Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/6/2002
Publication Date: 2/1/2003
Interpretive Summary: During the first week of life, baby chickens are susceptible to bacterial infections. Baby chicks have blood cells that can help them prevent these infections. These cells are called heterophils. The objective of this research was to compare heterophils from different types (A and B) of baby chicks and to see which chickens' heterophils were better able to kill bacteria. We found that roosters with strong heterophils passed on this ability to their baby chicks and that roosters with a weaker heterophil response also produced chicks with a decreased heterophil response. These experiments are important to the commercial poultry breeders because we have shown that if they use roosters with a strong heterophil response then the baby chicks will be stronger and may be able to fight off infections better.
Technical Abstract: Heterophils from two pure lines (A and B) of commercial broiler chickens were isolated on days 1, 4, and 7 post hatch to evaluated their ability to: (1) phagocytize Salmonella enteritidis (2) degranulate when exposed to immune-IgG opsonized SE, and (3) produce an oxidative burst. On days 1 and 4, heterophils from line A were functionally more efficient compared to heterophils from line B. By 7 days post hatch, heterophil functions for both lines were comparable. To determine if heterophil functional efficiency is heritable, heterophils from F1 crosses of the immunological efficient (A) and non-efficient (B) lines were evaluated for functional activity (line C = male B x female A; line D = male A x female B) and compared to parent lines. Heterophils from D had a more efficient heterophil function when compared to heterophils from C. Based on these results, heterophil function and efficiency can be genetically transferred to progeny. More specifically, the data suggests heterophil function is sex-associated and genetically controlled by the rooster since progeny of line A males maintained immunodominant characteristics whereas heterophils from the progeny of line B roosters remained immunologically inefficient. To our knowledge, this is the first report to describe a functional relationship between pure and F1 crosses of broiler chickens with regard to heterophils and the innate immune response.