Unabsorbed yolk sacs are being investigated as a possible reservoir for internal Campylobacter and salmonellae contamination of processed poultry carcasses. However, it is unknown at what frequency that unabsorbed yolk sacs persist at the time of processing of broilers and spent breeders. Seven sets of 100 broiler carcasses (at 6 or 8 wk of age) were obtained from commercial processing plants. ...

Yolk spheres present in mature invertebrate oocytes are composed of yolk proteins and proteolytic enzymes. In the fly Musca domestica, yolk proteins are degraded during embryogenesis by a cathepsin-like proteinase that is stored as a zymogen. An acid phosphatase is also active in the yolk spheres during Musca embryogenesis. In this paper we show that procathepsin and acid phosphatase are initia...

The correlation of yolk cholesterol and yolk fat concentrations of egg from the pedigreed Athens-Canadian Randombred control population with the percentage of abdominal fat (AF) and feed conversion ratio (FCR) of their progeny were studied. The average yolk cholesterol, yolk fat, and AF were 20.3 mg/g yolk, 244 mg/g yolk, and 1.64%, respectively. The phenotypic correlation of both yolk choleste...

Naja haje arabica (Arabian cobra) is the major cause of snake-bite mortality in Kingdom of Saudi Arabia. The treatments of the snake bite envenomation occur by anti-snake venom produced in horses previously immunized with a mixture of venom. Therefore, one of the main objectives of the current study is to produce anti Naja haje arabica immunoglobulin in high titer from the yolk of chickens by i...

The discovery by Schwabl that maternal steroid hormones are transferred to the egg yolk and have effects on the phenotype of offspring revealed a new pathway for non-genetic maternal effects. The initial model relied on passive transfer. The thinking was that steroids passively entered the lipophillic yolk during yolk deposition and then were deposited in the yolk until they were passively deli...