| Popis: |
The BG line was originated from the cross between 2 Chinese indigenous breeds, Dongxiang blue eggshell, and Jiangshan black-bone, and has been bred to combine dark heavy black-bone body and high production of blue-shell eggs, into single dual-purpose line. Full-pedigree hens from 2 generations, G4 (n = 441) and G5 (n = 464), were reared in the same single-cage laying facility in 2019-2020 and 2020-2021, respectively. Starting from the first egg of each hen, its daily egg production was recorded until 300 days-of-age. Up to 7 "no-egg" days were considered normal laying breaks between clutches, whereas laying cessation of 8 or more days was considered Pause, and the laying pattern of each hen was assigned either with Pause or No-Pause. The other traits included PsDays: number of Pause days; AFE: age at first egg; EN300: eggs laid until 300 d; %L300: total laying rate (EN300/[300-AFE]); %Lnet: net laying rate (EN300/[300-AFE-PsDays]); ClLng: average clutch length; EW200 and EW300: average egg weight around 200 d and 300 d. Estimates of heritability (h |
