Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/9/2001
Publication Date: 8/1/2001
Citation: CHENG, H., EICHER, S.D., CHEN, Y., SINGLETON, P.B., MUIR, W.M. EFFECT OF GENETIC SELECTION FOR GROUP PRODUCTIVITY AND LONGEVITY ON IMMUNOLOGICAL AND HEMATOLOGICAL PARAMETERS OF CHICKENS. JOURNAL OF POULTRY SCIENCE. 2001. V. 80. P. 1079-1086.
Interpretive Summary: Cannibalism and aggression are major behavioral problems that cause suffering and death of birds and reduce income of poultry producers. Genetic selection has been shown to be a vital tool for overcoming the problems and improving animal well-being. Genetically selected chicken lines have been developed at Purdue University, which emphasize group productivity based on average rate of lay and survivability based on average mortality from cannibalism. One line is selected for higher productivity and lower mortality, the other line is selected for lower productivity and higher mortality. The present study has shown that genetic selection for productivity and longevity also alters the birds' immunity. Present data suggest that conentrations of immune cell populations, and concentrations of antibody can be used as indicators by producers and scientists for evaluation of bird's well-being.
Technical Abstract: A line of birds was selected for high group productivity and longevity resulting in improved survival and feather score as well as reduced cannibalism and flightiness. Improvements in survival may have also been due to improved immunity. The present study was designed to test the hypothesis that selection for high (KGB) and low (LGP) group productivity and longevity also alters immune and hematological parameters. At 21 wks of age, the KGB birds had significantly higher percentage of blood lymphocytes and ratio of circulating CD4+ to CD8+ T-cells (P<0.01), and tended to have higher numbers of TCR1 cells (gamma delta,P=0.07) than the LGP birds. In contrast, the LGP birds exhibited significantly higher eosinophil numbers (P<0.01), heterophilia and an increased ratio of heterophils to lymphocytes (P<0.01). The concentrations of plasma immunoglobulin G were also significantly higher in the LGP birds (P<0.01). The results suggest that genetic selection for group productivity and longevity alters the birds' immunological and hematological systems.