Comparison of macrophage function in several commercial broiler genetic lines

The present study was conducted to establish baseline profiles of various macrophage functions in four commercial broiler genetic lines designated as Lines 1, 2, 3, and 4. All experiments were carried out between 2 to 3 wk of age. Total numbers of peritoneal exudate cells per bird collected 42 h after a single i.p. injection of Sephadex-G50 were comparable among the lines. Line 1 produced fewer macrophages along with reduced phagocytosis of opsonized SRBC, whereas Line 4 macrophages were depressed in unopsonized SRBC phagocytosis. Macrophages from Lines 2 and 4 killed internalized Escherichia coli earlier than macrophages from Lines 1 and 3. Supernatants from lipopolysaccharide-treated macrophages from Lines 1 and 2 exhibited significantly higher cytolytic activity against LSCC-RP9 tumor cells when compared with supernatants from Line 3 and 4 macrophages. The current study demonstrates genetic variation among the four broiler lines for mononuclear phagocytic system functions.