Time of Pigment Deposition in Brown Shelled Hen Eggs and in Turkey Eggs

The Relationship of Egg Shell Color to Hatchability in Some Brown Egg Laying Breeds

“…However, there are other factors involved as eggs from some hens laying light brown shell colored eggs have high hatchability. This variability agrees with the work of Warren and Conrad (1942) and Hall (1944) as they found no consistent differences between rate of pigment accumulation and intensity of laying. Therefore, other factors must be involved to bring about differences in hatchability between light colored and medium and dark brown shell colored eggs.…”

“…Warren and Scott (1935) reported that low intensity of production is due to both a longer period for passage of the egg through the oviduct (82 percent of the interval is accounted for by the time the egg remains in the uterus) and to a longer pause between clutches. Warren and Conrad (1942) reported that from 50 to 74 percent of the shell pigment is added in the last five hours before oviposition. Preliminary unpublished data seem to indicate that some dark colored eggs lose less moisture (14-day incubation moisture loss) than do some extremely light shell colored eggs.…”

Eggshell color in brown-egg laying hens — a review

“…Similarly, the eggshell pigmentation in Dongxiang blue-shelled chickens is thought to be secreted mainly 2.0 to 3.0 h before oviposition (Zhao et al, 2006). It is assumed that, in the hen, pigment is deposited onto brown eggs throughout the shell formation process, but 50 to 74 % of it is deposited in the last 5.0 h before oviposition (Warren and Conrad, 1942). From the presence of the pigment in all shell layers in brown-egg laying hens, it is assumed that pigment deposition follows a similar pattern to that seen in Japanese quail.…”

Effect of Season and Thyroidal Activity on the Molt Response to Progesterone in Chickens , ,

“…Warren and Conrad (1942) presented evidence that the greatest amount of shell pigment was added in the last five hours before oviposition. Warren and Conrad (1942) presented evidence that the greatest amount of shell pigment was added in the last five hours before oviposition.…”