Posterior Thoracic Air Sac Research Articles

Cervical air sac oxygen profiles in diving emperor penguins: parabronchial ventilation and the respiratory oxygen store.

Some marine birds and mammals can perform dives of extraordinary duration and depth. Such dive performance is dependent on many factors, including total body oxygen (O2) stores. For diving penguins, the respiratory system (air sacs and lungs) constitutes 30-50% of the total body O2 store. To better understand the role and mechanism of parabronchial ventilation and O2 utilization in penguins both on the surface and during the dive, we examined air sac partial pressures of O2 (PO2 ) in emperor penguins (Aptenodytes forsteri) equipped with backpack PO2 recorders. Cervical air sac PO2 values at rest were lower than in other birds, while the cervical air sac to posterior thoracic air sac PO2 difference was larger. Pre-dive cervical air sac PO2 values were often greater than those at rest, but had a wide range and were not significantly different from those at rest. The maximum respiratory O2 store and total body O2 stores calculated with representative anterior and posterior air sac PO2 data did not differ from prior estimates. The mean calculated anterior air sac O2 depletion rate for dives up to 11 min was approximately one-tenth that of the posterior air sacs. Low cervical air sac PO2 values at rest may be secondary to a low ratio of parabronchial ventilation to parabronchial blood O2 extraction. During dives, overlap of simultaneously recorded cervical and posterior thoracic air sac PO2 profiles supported the concept of maintenance of parabronchial ventilation during a dive by air movement through the lungs.

Immune Competence of Chicks from Two Lines Divergently Selected for Antibody Response to Sheep Red Blood Cells as Affected by Supplemental Vitamin E

Effects of dietary vitamin E on responses to SRBC antigens and Escherichia coli infection were studied in chicks from White Leghorn lines selected for 24 generations for high (HAS) and low (LAS) antibody responses to SRBC. Chicks were fed corn-soybean diets consisting of either high (300 IU per kg feed) or low (10 IU per kg feed) concentrations of vitamin E from the day of hatch through the end of experiment. The LAS chicks were heavier than the HAS chicks at 14 d of age and thereafter; there was no difference in BW between vitamin E concentrations. At 37 d of age, chicks were inoculated via the brachial vein with 0.1 mL of 0.25% SRBC suspension. Antibody titers at 6 and 10 d after inoculation were higher in HAS than in LAS chicks. At 6 and 10 d after inoculation with SRBC, antibody responses were lower in LAS chicks fed the diet containing the higher vitamin E concentration than in those fed the diet containing the lower concentration of vitamin E. At 64 d of age, chicks were injected in the posterior thoracic air sac with 0.1 mL of 10−2 or 10−4 dilution of Escherichia coli and scored for pericardial and air sac lesions. The HAS chicks were more susceptible to E. coli infection than LAS chicks as measured by lesion scores and BW changes. Although dietary vitamin E had no effect on lesion scores in either line, BW loss at 24 h after E. coli inoculation was significantly reduced in HAS chicks fed the higher concentration of vitamin E. The dosage of E. coli had no effect on lesion scores and BW changes. These results suggest that genetic selection might have changed immune competence in relation to responses to dietary vitamin E, and the optimum dietary concentration of vitamin E depends on genotype, among other factors.

Susceptibility of Convalescent Turkeys to Pulmonary Aspergillosis

Pulmonary lesions resulting from Aspergillus fumigatus inoculation were assessed in convalescent turkeys and compared with those in previously noninoculated (control) turkeys. In addition, lesions observed in small Beltsville white (SBW) turkeys were compared with those in broad-breasted white (BBW) turkeys challenged with the same inoculum. Turkeys were challenged by unilateral posterior thoracic air sac (PTAS) inoculation, rechallenged via the contralateral air sac after 5 wk, and then necropsied 1 wk later. Pulmonary lesions induced by the initial challenge had resolved in 6 of 10 SBW and 9 of 10 BBW turkeys. However, convalescence did not protect against pulmonary aspergillosis subsequent to rechallenge; 10 of 10 SBW and 9 of 10 BBW developed granulomatous pulmonary lesions on the side of reexposure. A greater proportion of control SBW turkeys developed pneumonia and airsacculitis following challenge as compared with the BBW breed. Lesions were limited to the lower respiratory tract in all turkeys and were confined to the ipsilateral lung and PTAS in the singly inoculated control turkeys. This study demonstrates that convalescence from pulmonary aspergillosis does not confer protection against rechallenge but may, instead, decrease resistance to subsequent infection.

The effects of the wingbeat cycle on respiration in black-billed magpies (Pica pica)

Interclavicular and posterior thoracic airsac pressures, tracheal airflows and pectoralis muscle activity were recorded simultaneously to determine the effect of the wingbeat cycle upon the function of the respiratory system. The effects of the wingbeat cycle on the relative positions of thoraco-abdominal skeletal structures were also assessed using high-speed X-ray cinematography of magpies Pica pica flying in a windtunnel. We found that the furcula bends laterally on the downstroke and recoils medially on the upstroke, as previously described for starlings, and that the coraco-sternal joint (the most consistently visible point on the sternum for digitization) is displaced dorsally during the downstroke and ventrally, with respect to the vertebral column, during the upstroke. In magpies, there are generally three wingbeat cycles during a respiratory cycle. When downstroke occurs during inspiration, its compressive effect reduces the inspiratory subatmospheric airsac pressure by an average of 92 % (0.35 kPa), whereas when upstroke occurs during expiration its expansive effect can reduce the expiratory supra-atmospheric airsac pressure by 63 % (0.23 kPa). Corresponding changes occur in tracheal airflow. Changes in respiratory parameters during short flights with respect to resting values include a doubling of tidal volume and a tripling of respiratory frequency. We conclude that the wingbeat cycle can have a substantial impact on respiratory system function in the flying magpie, and that this represents a mechanical basis for breathing patterns and patterns of phasic coordination between wingbeat and respiratory cycles that may result in minimal interference and maximal assistance from the wingbeat upon the respiratory cycle.

Effect of Spectinomycin on Escherichia coli Infection in 1-Day-Old Ducklings

Two challenge trials and one confirmation trial were conducted to evaluate the efficacy of spectinomycin in the treatment of 1-day-old ducklings infected with Escherichia coli. In the challenge trials, ducklings were injected in the right posterior thoracic air sac with 0.2 cm3 of broth containing 10(8) colony-forming units E. coli (strain O78, E38)/ml. Spectinomycin at dosage levels of 2.5 mg, 5.0 mg, and 10.0 mg of activity was injected subcutaneously 6 hours following infection. The confirmation trial was conducted to confirm the challenge trials; procedures were similar to those used in the challenge trials, except that only the 5.0 mg of activity dosage of spectinomycin was used. In both types of trials, spectinomycin-treated ducklings had significantly lower mortality and higher average weight gain, average daily gain, and feed consumption than infected unmedicated controls. These results indicate that spectinomycin is effective in treating ducks for experimentally induced colibacillosis caused by E. coli (strain O78, E38).

Escherichia coli Challenge in Chickens Selected for High or Low Antibody Response and Differing in Haplotypes at the Major Histocompatibility Complex

Relative sensitivity to Escherichia coli challenge was evaluated in white leg-horn chickens that had been selected for high antibody (HA) or low antibody (LA) response and that differed in haplotypes at the major histocompatibility complex (MHC). Assessments were made of relative body-weight change and of heart and air-sac lesions after inoculation of 10(6), 10(5), or 10(4) E. coli via the posterior thoracic air sac. As has previously been reported, chicks from line HA were more sensitive to E. coli than those from line LA. Lesion scores were 1.58 +/- 0.12 in line HA and 1.02 +/- 0.12 in line LA (mean +/- S.E.), and ranged from 0.99 +/- 0.14 with the lowest dose of E. coli to 1.79 +/- 0.15 for the highest dose. Relative body-weight change to 72 hours after inoculation was greater in line LA (7.5 +/- 0.5) than in line HA (4.4 +/- 0.8). There was no apparent resistance or susceptibility conferred to chickens in either the HA or LA genetic background as a result of haplotypes present at the MHC.

High-frequency ventilation of ducks and geese.

We studied gas exchange in anesthetized ducks and geese artificially ventilated at normal tidal volumes (VT) and respiratory frequencies (fR) with a Harvard respirator (control ventilation, CV) or at low VT-high fR using an oscillating pump across a bias flow with mean airway opening pressure regulated at 0 cmH2O (high-frequency ventilation, HFV). VT was normalized to anatomic plus instrument dead space (VT/VD) for analysis. Arterial PCO2 was maintained at or below CV levels by HFV with VT/VD less than 0.5 and fR = 9 and 12 s-1 but not at fR = 6 s-1. For 0.4 less than or equal to VT/VD less than or equal to 0.85 and 3 s-1. less than or equal to fR less than or equal to 12 s-1, increased VT/VD was twice as effective as increased fR at decreasing arterial PCO2, consistent with oscillatory dispersion in a branching network being an important gas transport mechanism in birds on HFV. Ventilation of proximal exchange units with fresh gas due to laminar flow is not the necessary mechanism supporting gas exchange in HFV, since exchange could be maintained with VT/VD less than 0.5. Interclavicular and posterior thoracic air sac ventilation measured by helium washout did not change as much as expired minute ventilation during HFV. PCO2 was equal in both air sacs during HFV. These results could be explained by alterations in aerodynamic valving and flow patterns with HFV. Ventilation-perfusion distributions measured by the multiple inert gas elimination technique show increased inhomogeneity with HFV. Elimination of soluble gases was also enhanced in HFV as reported for mammals.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunogenicity of an Escherichia coli Multivalent Pilus Vaccine in Chickens

Immunogenicity of an oil-emulsified Escherichia coli multivalent pilus vaccine was evaluated in 4-week-old chickens. The vaccine contained 180 micrograms of pilus protein from each of serotypes O1 and O78 and 170 micrograms of pilus protein from serotype O2. Chickens were vaccinated twice subcutaneously at 4 and 6 weeks old and challenged via the posterior thoracic air sac with E. coli serotype O1, O2, or O78 2 weeks after the last vaccination. Unvaccinated challenged chickens suffered 8% to 26% mortality; no vaccinated chickens died. Vaccinated chickens had very mild gross lesions in the air sacs, livers, and pericardial sacs and eliminated E. coli more efficiently than the unvaccinated challenged chickens. The results showed that a multivalent pilus vaccine protects chickens against active respiratory infection.

Pathological Changes of Tracheal Mucosa in Chickens Infected with Infectious Laryngotracheitis Virus

Six-week-old chickens were inoculated via the posterior thoracic air sac with infectious laryngotracheitis virus. Chickens were sacrificed on various days through day 16 postinoculation (PI), and the trachea was examined by scanning electron microscopy (SEM) and light microscopy (LM). The pathological changes observed on day 1 PI were hypertrophy and hyperplasia of goblet cells. From day 3 PI, the epithelial cells protruded collectively and fused to form syncytia, which contained many intranuclear inclusion bodies. Subsequently, epithelial syncytia desquamated, one after another, and connective tissues were exposed in places. Serofibrinous exudate and detritus were abundant on the surface of the exposed connective tissues and seemed to form a pseudomembrane. On day 5 PI, the remaining epithelial cells began to repair the devastated mucosa just under the pseudomembrane. On day 6 PI, microvillus-rich regenerating epithelial cells were arranged like paving stones. On day 8 PI, the epithelial cells proliferated extensively and formed folds with cyst-like structures. By day 16 PI, the tracheal epithelium was covered with cilia and regained its normal histologic appearance.

Immunogenicity of an Escherichia coli (Serotype O1) Pili Vaccine in Chickens

Immunogenicity of an oil-emulsified Escherichia coli (serotype O1) pili vaccine was evaluated in chickens. Chickens were vaccinated with 116 micrograms or 29 micrograms of pili protein and challenged with the homologous E. coli via the posterior thoracic air sac. Unvaccinated chickens were challenged to serve as positive controls or left unchallenged to serve as negative controls. Vaccinated chickens were protected against challenge because they suffered low or no mortality; had mild gross lesions in air sacs, pericardial sacs, and livers, and the scored values were significantly (P less than or equal to 0.05) lower than those in the positive controls; and eliminated E. coli from tissues more efficiently than the positive controls.

Dactylariosis: A Newly Recognized Fungus Disease of Chickens

SUMMARY A fatal encephalitis of chickens, caused by the thermophilic fungus Dactylaria gallopava, affected over 200 birds in a flock of 65,000 broilers. The disease was reproduced experimentally by inoculating spore suspensions into 1-day-old chicks via the left posterior thoracic air sac, the left maxillary sinus, and also intracerebrally. Gross and microscopic lesions were found in the brains, air sacs, lungs, eyes, and livers. The brain lesions were like those in the natural outbreak, and D. gallopava was recovered from the inoculated chickens. The brain lesions were compared with those in birds with aspergillosis.

Experimental mycoplasmosis in chickens. II. Pathological findings of chickens inoculated with Mycoplasma gallisepticum (strain S6) by the air-sac and intravenous routes

Over a period from 1964 through 1968 a series of experiments on mycoplasrnosis in?chickens were carried out to investigate clinical signs, anatomico- and histopathologicallesions, and recovery of the organism inoculated. In them, chickens were inoculated withrMycoplasma gallisepticum (MG) directly into tlae posterior thoracic air-sac (PAs), intra-venously (IV) into the wing vein, or by the combined routes, PAs and IV. The resultsof the clinical observation and recovery of the inoculated organism from tlae chickenswere reported in a previous papers).The objectives of the present experiments were (l) to examine the [esions of theair-sac and other organs and tissues of chickens following inoculation with the organismand (2) to determine differences in lesions of chickens inoculated among the three types, of inoculation. The outline of the experiments is given in Table l to 4. The materialsand methods used in the present experiments were the same as mentioned in the previouspaper20). Tlte results obtained are summarized as follows.l. Lesions caused by MG inoculated into the PAs were generally mild in nature.They were found mainly in the respiratory organs, including the air-sacs, and subsequentlyin the spleen. After intravenous inoculation with MG, proliferation of lymphoreticulartissues produced characteristic lesions in the spleen and liver. No lesions, however, werefound in any of the air-sacs.2. Primary lesions found 6 hours after .lV[G inoculation into the PAs howed thickening of the air-sac due to new formation of bl6od capillaries, edema, congestion, and infiltration of monocuclear leukocytes. The most conspicuous lesions in the air-sacs examined?on the 7th day after exposure showed a tendency to undergo repair approximately onthe 12th day after inoculation.3. After intravenous inoculation with MG, lesions were found mainly in the spleen, liver, and respiratory organs, except the air-sacs. In a few cases mild inflammatory reac, tions were found to have occurred in the intestines, heart, kidneys, pancreas, crop

Structure of avian lungs

Injection casts of the lung air sac system of 155 species of 47 families of birds were studied, together with preparations of fixed specimens of 45 species. Besides measurements of the fractional distribution of the volumes of the lung and the air sacs, the exchange surface of the air capillaries was determined in 8 species. The avian lung is firmly attached to the thoracic wall and remains constant in volume during both phases of respiration. The primary bronchus enters the lung, giving off at the hilus 4 ventrobronchi and, posteriorly, 7 to 10 dorsobronchi besides some laterobronchi, before it enters the abdominal air sac. The posterior thoracic air sac is connected to one large laterobronchus. These posterior air sacs act as bellows ventilating the lung, much more than the anterior air sacs which are connected to single ventrobronchi. The special manner of the origin of the ventro-, dorso- and latero-bronchi from the primary bronchus is responsible for the ventilation of the parabronchi which connect the total internal surfaces of the dorsobronchi and ventrobronchi. This structure is the “paleopuimo”, found in all birds. Systematically higher birds possess an additional connecting network of parabronchi between the primary bronchus and the posterior air sacs. This “neopuimo ” is best developed in fowllike birds and song birds. The tissue mantle of the parabronchi is made up of a meshwork of blood and air capillaries within which the gas exchange takes place. Development of small air capillaries requires a constant lung volume. The effective exchange surface per volume unit is ten times larger than that of comparable mammalian lungs.

Failure of M. Gallisepticum Infection to Predispose Chickens to Coliform Pericarditis

In II separate experiments 450 chickens, most of broiler age, were inoculated with pathogenic E. coli via the infra-orbital sinus, the left posterior thoracic air sac or the trachea. Half of the chickens were previously inoculated with M. gallisepticum, also by one of these routes. Sixty-three chickens developed coliform pericarditis but these were divided almost equally between the mycoplasma-free and the mycoplasma-infected birds. No evidence was produced by the experiments to support the view that M. gallisepticum infection per se is an important predisposing infection in the pathogenesis of coliform pericarditis. Au cours de II experiences distinctes on a inoculé 450 poulets, pour la plupart d’âge d’être rôtis, avec des E. coli pathogènes par voie du sinus infra-orbitaire, du sac d’air thoracique postérieur gauche ou de la trachée. Une moitié des poulets avait été inoculée au préalable par M. gallisepticum, également par une de ces voies. Soixante-trois poulets développèrent une pericardite due aux colibacilles, mais parmi-ceux-ci il y avait à peu près une moitié d’oiseaux sans mycoplasma, et une moitie d’oiseaux infectés par les mycoplasma. On n’a pu par ces expériences donner appui à l’hypothèse suivant laquelle l’infection par M. gallisepticum est par elle-même une infection importante dans la prédisposition à la pathogénie de la pericardite due aux colibacilles. In II Versuchen wurden 450 voll entwickelte Hühner mit pathogenen E. coli inokuliert und zwar infraorbital, oder im 1. hinteren Luftsack des Thorax oder in der Trachea. Die Hälfte der Hühner war vorher mit den gleichen Methoden mit M. gallisepticum inokuliert worden. Dreiundsechzig erkrankten an Coli-Pericarditis, aber von ihnen waren etwa die Hälfte frei von Mycoplasma, während die andere Hälfte Mycoplasma-infiziert war. Diese Versuche bestärkten in keiner Weise die Ansicht, dass eine Infektion mit M. gallisepticum and sich ein wichtiger prädisponierender Faktor für die Pathogenese einer Coli-Pericarditis sei. En 11 experimentos distintos 450 pollos fueron inoculados con cepas patógenas de E. coli . La inoculación de hizo en el saco torácico de la tráquea a través del seno infra-orbital El 50 por ciento de los pollos había sido previamente inoculado con M. gallisepticum . Los 63 pollos que desarrollaron pericarditis coliforme pertenecían casi por igual al grupo infectado con mycoplasma que al grupo no infectado. No se halló evidencia alguna de que la infección por M. gallisepticum sea de suyo un factor predisponente a la pericarditis coliforme.

Study on the structure of the air sacs in the turkey (Meleagris gallopavo) based on comparative observations with the domestic fowl (Gallus domesticus), guinea fowl (Numida meleagris), common pheasant (Phasianuas colchicus), korean ring-necked pheasant (Phasianus colchicus karpowi) and indian peafowl (Povo cristatus)

This investigation was carried out to provide a comparative anatomical picture of the air sacs between the turkey and the other species of galliformes.The results obtained are summarized as follows.As for the connections between lung and air sacs, they were usually eight connections in the domestic fowl, guinea fowl, common pheasant, korean ringnecked pheasant and indian peafowl. The connections in the turkey were usually five. No direct connection of no. 2 posterior ventral secondary bronchus to the posterior thoracic air sac, and direct connection of no. 3 anterior dorsal secondary bronchus and the connections by primary bronchus of a few tertiary bronchi formed by branches of no. 1, 2 and 4 anterior dorsal secondary bronchi to the interclavicular air sac were observed as compared with those in other species.The cervical air sac of the turkey connected to no. 1 anterior dorsal secondary bronchus, and it connected with m. longus colli on the dorsal side and with oesophagus on the ventral side. The system was the same in the other birds of the galliformes. The cervical air sac of the turkey, however, united strongly with interclavicular air sac, where situated in the both sides between the 13th and the 16th of vertebrae. The interclavicular air sac of the turkey extended to the sternal part of costae, which existed the anterior thoracic air sac in the birds of the galliformes except the turkey.In the turkey, no posterior thoracic air sac which connected to no. 2 posterior ventral secondary bronchus was seen, and the anterior thoracic air sac was observed in the same region.The diverticula, interpectoral, axillary and others in the turkey, connected to the interclavicular air sac at the part of dorsal side of pneumatic foramen of coracoideum.In the turkey air sacs were six as total, cervical (single), interclavicular (single), anteriorthoracic (paired) and abdominal air sac (paired) as compared with those of the other species which were eight (in the case of single cervical air sac) or nine (in the case of paired cervical air sac).In the method of latex, the supramedulla sacs of the turkey which communicated into the canalisvertebralis through the for. intervertebrale from the air sacs of the out side of vertebrae were not always continued in the canalis vertebralis.No existance of the supramedulla sacs was noticed in the canalis vertebralis of synsacrum.In the adult turkey, bones which communicated with air sacs were vertebrae, costae, sternum. coracoideum, scapula, humerus and os coxae.There was no sign of the air sac in the os femoris of turkey, domestic fowl and guinea fowl, having no pneumatic foramen. In the common pheasant, korean ring necked pheasant, otherwise, the air sac communicated into the os femoris in the existence of pneumatic foramen.

A study of the effect of egg separation on hatching time and of the source of clicking sounds in the embryo of the domestic chicken

The phenomenon of synchronized hatching was studied in a two-part investigation using White Leghorn and Rhode Island Red embryos and chicks. Experiments were conducted to test for the effect of separating eggs on hatching time and to locate the source of clicking sounds emitted by embryos during the final hours of incubation.A total of 25 eggs separated by no less than 4 in. and five clutches, each with 10 eggs in contact, were incubated and their hatching times compared. There was no difference in the mean hatch times of separated versus contact eggs. Separated eggs, however, were more variable in their hatch times than contact eggs, a statistical analysis showing a significant difference at the 0.05 level.Recordings were made of audible activity produced by embryos from their 17th day of incubation, and of hatched chicks up to 2 days after hatching. Clicking sounds from within the embryos were heard from 2 to 7 h after pipping (first puncture of the egg shell) had occurred. The source of the clicking was associated primarily with the right abdominal air sac and possibly with the right posterior thoracic air sac of the respiratory system. Other observations are described.

Mycoplasma gallisepticum in a Commercial Laryngotracheitis Vaccine

The vertical transmission of Mycoplasma gallisepticum has been well documented. The possibility that egg-propagated vaccines could become contaminated with this organism has been recognized for some time (6). The finding by Conrad (2) in 1958, that a portion of the avian Mycoplasma population in egg yolk survives lyophilization tended to substantiate the possibility of vaccine contamination. In 1962 and again in 1965, study groups (8,9) on avian Mycoplasma infections recommended "that all eggs used in the production of poultry biologics . . . be obtained from flocks free of M. gallisepticum." While bacterial contamination of poultry vaccines has been demonstrated (3,12), Oshel and Gourlay (7) did not detect antibodies against Mycoplasma gallisepticum using 55 serial lots of Newcastle disease, infectious bronchitis, or combination Newcastlebronchitis vaccines inoculated into the posterior thoracic air sac of two-week-old chicks.

The Clinical Course of Infectious Sinusitis in Experimentally Infected Turkeys

THE clinical course and the effect of infectious sinusitis in individual turkeys or flocks deserves further delineation. Hinshaw's4 brief discussion on the course and mortality is generally accepted: Sinusitis of the obviously contagious type runs a chronic course and may exist in a flock for weeks. Although the number of deaths may be less than in some more acute diseases, the financial loss may be greater. Failure to gain weight accounts for as much damage as does mortality. Boyer et al.2 in one of two experiments, studied the course of infectious sinusitis of turkeys over a 3 week period and observed recovery from the lower respiratory form of the disease, with practically no recovery from swollen sinuses. In an experimental inoculation of the infectious sinusitis agent into the posterior thoracic air sac, the same writers produced respiratory symptoms in seven days. The incubation period of the disease was found by Jerstad et al.6 to vary considerably and may be dependent on agent virulence, age of