The capacity of cecropia vitellogenic follicles to form yolk during short-term in vitro incubation in female blood was analyzed by labeling with fluorescein-conjugated serum globulin, tritiated cecropia blood proteins, or tritiated amino acid. As judged by fluorescence microscopy or autoradiography, yolk formation during 3-8 hr in vitro was similar in rate and in protein uptake specificity to t...

The objective of this study was to investigate the deposition rule of yolk cholesterol in Lushi Green-shelled and Silky Fowl layers. A total of 90 layers of each breed were selected at an age of 15 to 51 weeks. Productive performance was recorded on a weekly basis, whereas yolk cholesterol was determined at 4-week intervals from 21 to 51 weeks of age. The average yolk cholesterol content of Sil...

The effect of a dietary supplementation of gallic acid and linoleic acid mixture (MGL) and their synthetic salt, sodium 2,3-dihydroxy-5-(((9E,12E)-octadeca-9,12-dienyloxy)carbonyl)phenolate (NGL), on egg quality was investigated. A total of 120 laying hens were allotted into five groups over 4weeks of the experimental period. Birds were fed the following diets: (1) control [commercial diet (CD)...

In two trials, the effects of F-strain Mycoplasma gallisepticum (FMG) on the contents of egg yolks from commercial Single Comb White Leghorn laying hens were investigated over a production cycle. Ten hens were assigned to each of 8 (trial 1) or 16 (trial 2) negative pressure fiberglass biological isolation units. Birds in half of the total units served as sham-inoculated controls, and those in ...

The objective of the present study was to determine the effects of docosahexaenoic acid (DHA)-enriched hen egg yolks and L-cysteine supplementation on the qualities of the cryopreserved boar semen. A total of 15 ejaculates from 5 Pietrain boars were divided into 4 groups according to the compositions of the freezing extenders used, that is, normal hen egg yolk (group I), DHA-enriched hen egg yo...

Vascular endothelial growth factor A (VEGFA) plays a pivotal role in the first steps of endothelial and haematopoietic development in the yolk sac, as well as in the establishment of the cardiovascular system of the embryo. At the onset of gastrulation, VEGFA is primarily expressed in the yolk sac visceral endoderm and in the yolk sac mesothelium. We report the generation and analysis of a Vegf...

Egg yolk low-density lipoproteins (LDL) and soybean lecithin were evaluated as replacements for egg yolk in extenders used for the cryopreservation of brown-bear spermatozoa. The motility, viability and acrosomal status of post-thawed spermatozoa were analysed, and an egg-yolk extender was used as a control. The total antioxidant capacity of these extenders was tested. Soybean lecithin showed a...

Vitellin (Vt) was found not to be critical to the formation or structure of yolk spheres in oocytes of the moth, Plodia interpunctella (Hubner). Vitellogenic activities of the follicular tissues were determined by visualizing the immunocytolocalization of Vt subunits (YP1 and YP3) and of a follicular epithelium yollc protein (FEYP) subunit (YP2) in ultrathin sections or in whole-mounted tissues...

Phosvitin is a yolk phosphoglycoprotein bound to lipoproteins within the yolk granules. Its absorption and utilization during chick embryogenesis is still unclear. The presence of phosvitin was investigated by immunodiffusion techniques in the watersoluble fraction (WSF) of the yolk during oocyte maturation and chick development and in the embryonic fluids. The immunochemical analysis showed th...