STUDY ON BLOOD BIOCHEMICAL INDICES OF EARLY SELECTION FOR LAYER
Zhou Hongsong Zhao Yixian(Department of Animal Sciences and Veterinary) Zhang Liming Ye Ruilan Lu Cuizhen Tan Huayong Li Chun Zhao Huili (Central Laboratory)
Nine blood biochemical indices of White Leghorn Line S220 chicks at age of 8 and 12 weeks were tested. The phenotypic and genetic correlations between these indices and egg laying performance as well as heritabilities of these indexes were estimated. The results showed that the heritabilities of both percentage content of serum albumin at 8-weeks (8-SAW) and of egg production at 300-days (300-EPD) and their genetic correlation were 0.54, 0.23 and 0.7945, respectively. The heritabilities of both serum AKP activity at 8-wk (8-SAAW) and of egg production at 300 -days(300-EPD)and their genetic correlation were 0.62, 0.20 and 0.8245, respectively. The efficiency of indirect selection to 300—EPD by 8—SAW and 8-SAAW as the secondary trait was 1.2174 and 1.4519, 1.4460 and 1.4873, 1.0826 and 1.1887 times as large as individual selection, family selection and combination selection, respectively. Hence, percentage content of 8-SAW and 8-SAAW can be regarded as blood biochemical indexes of layer for early selection.