In vitro cultures of isolated fowl embryo otocysts were studied with the electron microscope. Hair cells of the developing organ of Corti and crista ampullaris have been examined with particular reference to the structure of the cilia and of the cell membrane. Two types of hair cells could be distinguished on the basis whether or not they possessed a "kinocilium" and "stereocilia," or "stereoci...

Introduction of novel inactivated oil-emulsion vaccines against different strains of prevailing and emerging low pathogenic avian influenza (LPAI) viruses is not an economically viable option for poultry. Engineering attenuated Salmonella Gallinarum (S. Gallinarum) vaccine delivering H5 LPAI antigens can be employed as a bivalent vaccine against fowl typhoid and LPAI viruses, while still offeri...

Aim: An attempt has been made to identify and study the nucleotide sequence variability in exon 5 exon 6 regions of guinea fowl Tapasin gene. Materials and Methods: Blood samples were collected from randomly selected birds (12 guinea fowl birds) and Tapasin gene amplified using chicken specific primers designed from GenBank submitted sequences. Polymerase chain reaction conditions were standard...

Four strains of Salmonella gallinarum isolated from independent cases of fowl typhoid all possessed both an 85-kilobase and a 2.5-kilobase plasmid. Each plasmid was eliminated in turn from one of the strains by transposon labeling and curing at 42 degrees C. Elimination of the small plasmid had no effect on the high virulence of the strain for newly hatched and 2-week-old chickens. Whereas oral...

The three-dimensional structure and size of ostrich sperm is unknown. In this study, the morphology and dimensions of ostrich sperm were determined by scanning electron microscopy of semen samples obtained from sexually mature males during the breeding season. The results indicate that sperm cells of the ostrich are of the sauropsid type characteristic of non-passerine birds and, in general app...

Some parameters of the reactivation of ultravioletor chemically inactivated fowl plague virus by live A 2 viruses were examined. Clones of reactivated virus were obtained by two different techniques, either by isolation from plaques on chick embryo fibroblast cells or by terminal dilution in pieces of allantois-on-shell. Recombinants isolated from plaques were of one type, namely they contained...

There has been no study aimed at directly determining of the periods of Sertoli cell proliferation in birds even domestic fowl. The aims of this study were to observe the cessation of post-hatching mitotic proliferation of Sertoli cells in domestic fowl, and to determine the volume density of Sertoli and germ cells during this period. A total of 50 Leghorn chicks were used in this study. The te...

Lung ventilation of tetrapods that synchronize their locomotory and ventilatory cycles during exercise could be economized if the resonant frequency of the respiratory system matched the animal's preferred step frequency. To test whether animals utilize this strategy, the input impedance of the respiratory system of five anesthetized, supine guinea fowl (Numida meleagris) was measured using a f...

The fertilization success of an insemination is at risk when a female has the possibility to copulate with multiple males, generating sperm competition and sexual conflict over remating. Female propensity to remate is often reduced after copulation, and a staggering diversity of highly derived male traits that discourage female promiscuity have been investigated. However, it is difficult to sep...

of inactivated (heated at 80° for 30 min.) intestinal mucosa of hens, and the optimum pH for the enzyme of mature fowl was not altered by inactivated mucosa of chicks. 3. A mixture of the enzyme preparations of chicks and mature fowl exhibited a pH-activity curve and quantitative reaction velocities which would be expected from a combination of two enzymes possessing different pH optima. 4. In ...