Double-yolked pheasant eggs provide an insight into the control of albumen secretion in bird eggs

Abstract

International audience1. The possible role of the presence of the yolk in stimulating secretion of albumen was investigated. 2. Double-yolked and single-yolked pheasant (Phasianus colchinus) eggs were opened to determine the masses of the shell, albumen and yolk(s). 3. In double-yolked eggs, the two yolk masses were not significantly different. Albumen mass was increased above that expected from an egg with a single-yolk of comparable size but below that expected from an egg having a mass of the combined yolks. The mass of shell per unit area reflected the mass of the initial mass of the egg irrespective of the number of yolks. 4. The additional mass of albumen is unrelated to yolk or initial egg mass. It is postulated that in double-yolked eggs the oviduct is mechanically stimulated by the presence of both yolks, which empties the stores of water-soluble albumen proteins in the magnum wall. Such stores are insufficient to provide the same amount of protein for the two yolks

Occurrence of twin embryos in the eastern bluebird

“…1 ). Based on an image analysis, the larger egg was approximately 11% longer and 12% wider than the mean of the other three eggs (as measured in pixels), which is within the range reported for double-yolked eggs of other species ( Jeffrey, Fox & Smyth, 1953 ; Pattee, Mattox & Seegar, 1984 ; Deeming, 2011 ; Salamon & Kent, 2013 ). All eggs were the same pale blue color, characteristic of the species.…”

“…(1999) for exceptions). Double-yolked eggs, which tend to be larger and heavier than single-yolked eggs ( Pattee, Mattox & Seegar, 1984 ; Deeming, 2011 ; Salamon & Kent, 2013 ), form when two yolks ovulated within three hours of each other become enclosed in one egg ( Conrad & Warren, 1940 ). According to data on embryonic death in the double-yolked eggs of domesticated fowl, there are two mortality peaks during embryo development, one during days 7–14 of incubation, and another from days 18–23 of incubation; only 3.8% of double-yolked eggs survived to hatching stage ( Romanoff & Romanoff, 1972 ).…”

A grape seed extract maternal dietary supplementation improves egg quality and reduces ovarian steroidogenesis without affecting fertility parameters in reproductive hens: a link with plasma and ovarian cell adipokines expression?

“…However, the GSE supplementation reduced the incidence of double-yolk eggs. The double-yolked avian egg is a common physiological process in commercial species of poultry (40,41). Double-yolk eggs are formed when two F1 follicles ovulated within three hours of each other become enclosed in one egg (42), and estimated to occur in 4 ~…”

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“…We speculate that the eastern bluebird twins likely resulted from a double-yolked egg (binovular twins) since the nest contained a relatively large egg, and according to Romanoff and Romanoff (1972), monovular twins are more likely to result from a normal-sized egg (but see Petty &Anderson, 1989 andBassett et al, 1999 for exceptions). Double-yolked eggs, which tend to be larger and heavier than single-yolked eggs (Pattee, Mattox, & Seegar, 1984;Deeming, 2011;Salamon & Kent, 2013), form when two yolks ovulated within three hours of each other become enclosed in one egg (Conrad & Warren, 1940). According to data on embryonic death in the double-yolked eggs of domesticated fowl, there are two mortality peaks during embryo development, one during days 7-14 of incubation, and another from days 18-23 of incubation; only 3.8% of double-yolked eggs survived to term (Romanoff & Romanoff, 1972).…”