Authors : Yao-Dong Hu, Jie Wen, Mai-Qing Zheng, Ran-Ran Liu, Ji-Lan Chen, Qing Zhu and Gui-Ping Zhao
Abstract: Four generations of bi-directional selection for antibody response to challenge with SRBC on days 56 were completed in White Leghorn chickens. The anti-SRBC titer and other immune traits were measured in up-selected (H), down-selected (L) and Control (C) lines in each Generation (G0-G4) and reproductive traits were measured in G4. In the 4th generation, the difference in SRBC titers (measured on days 61) between the selected lines was 7.18 versus 6.10, a 17% increase in the H compared to the L lines. The heritability of SRBC titer was 0.26. The genetic correlations between anti-SRBC and IgG (0.87) and IgM (0.81) were high and those between SRBC titers and those against AI (0.56), ND (0.48) and the H/L ratio (0.58) were moderate. Immune and reproductive traits compared among the H, L and C lines in the final Generation (G4) showed that AI, ND and IgM were improved significantly (p<0.05) by selection for SRBC but the age at first lay was slightly delayed (0.48 days) in the H line. This study demonstrates that selecting for antibody response to SRBC improves other immune traits consistent with broad disease resistance of chickens.
Yao-Dong Hu, Jie Wen, Mai-Qing Zheng, Ran-Ran Liu, Ji-Lan Chen, Qing Zhu and Gui-Ping Zhao, 2012. Correlated Responses to Bi-Directional Selection for Sheep Red Blood Cell Titer in White Leghorns. Journal of Animal and Veterinary Advances, 11: 2879-2884.