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At least 973 records · Page 54Linked to original sources
PubMed1984

Comparison of the effect of DDE on the Ca metabolism of the eggshell gland and its subcellular fractions of the duck and the domestic fowl.

In a strain of ducks sensitive to the eggshell-thinning effect of p-p'-DDE, administration of 40 mg kg of the compound in the food for 45 days reduced the eggshell index (EI) by 13% and the content of calcium in the fluid of the shell gland forming an eggshell by 36%, and raised the calcium content of the shell gland mucosa by 19%, compared with the control values. DDE inhibited the translocation (secretion) of calcium between the gland mucosa and the uterine cavity. The ATP-dependent binding of Ca2+ to the subcellular fractions of the gland mucosa was reduced in DDE-treated ducks. The Ca2+ binding to a microsomal subfraction (FI) rich in fragments of the plasma membrane was reduced by 16%, whereas that to a subfraction FIII which bound Ca2+ at a very high rate was reduced by 36%. The latter may contain calcium-secreting granules of the gland. In the mitochondrial fraction the Ca2+ binding was reduced by 35%. In the domestic fowl DDE did not lower EI or interfered with the translocation of calcium between the shell gland mucosa and uterine cavity. DDE administration increased the Ca2+ binding to FI by 26%; the binding to other subfractions was not changed significantly. DDE may interfere with the stimulus-secretion mechanism of the eggshell gland in ducks through its effect on Ca2+ binding.

Adenosine Triphosphate↗
PubMed1987

Methyl mercury decreases the eggshell thickness and inhibits the Ca2+ uptake in a homogenate of the eggshell gland mucosa and its subcellular fractions from the domestic fowl.

In the domestic fowl 20 mg of methyl mercuric chloride (MeHg) in a single oral dose given a day before egg-laying reduced the eggshell index by 35% and decreased the Ca content of the eggshell by 31% compared with those in the eggs laid on the previous days. The plasma concentration of Ca was reduced by MeHg by 50% in comparison with controls. The Ca concentration in the shell gland mucosa was not decreased by MeHg in relation to the control value. The rate of ATP-dependent Ca2+ binding by the homogenate of the mucosa was reduced by 33% by MeHg in relation to the control rate. The activity of Ca2+-Mg2+-ATPase was not changed.

Adenosine Triphosphatases↗
PubMed1981

The anaerobically cultured cecal flora of adult fowls that protects chickens from Salmonella infections.

In this work we have analyzed the bacterial composition of anaerobically cultured cecal contents (mixed broth culture) of adult fowls previously shown able to protect 1 day old chickens from oral Salmonella infections. All four cultures studied in this paper gave complete protection against Salmonella infantis when used undiluted or in the 10(-2) dilution and at least some protection in the 10(-4) dilution. The total aerobic as well as anaerobic counts on the nonselective medium used (VLMH) were of the order of 10(8) viable organisms/ml indicating that the mixed broth culture consisted predominantly of facultative organisms. From a total of 239 colonies isolated on the basis of colony morphology 66 were obligate anaerobes and 173 facultative anaerobic or microaerophilic species. Isolates were selected from each medium. They were grouped and tentatively classified on the basis of their ability to grow on selective media, their colony and cell morphology. Gram stain and products formed from glucose fermentation (obligate anaerobes). Further characterization was performed using conventional carbohydrate fermentation and biochemical tests. However only a minor fraction of the anaerobic isolates could be identified as being identical to known species. The most numerous species were E. coli and various Lactobacilli which were still found in the highest dilution (10(-8)) of the broths. Fecal streptococci were the next most frequent, isolated at the 10(-7) dilution. The obligate anaerobes isolated included Gram-positive cocci and Gram-positive and -negative rods tentatively classified as Eubacteria, Propionibacteria, Clostridia, Fusobacteria and Bacteroides. A large number of them were isolated from the 10(-6) dilution and some species of Eubacteria and Clostridia could only be recovered from the 10(-3) or 10(-4) dilutions.

Anaerobiosis↗
PubMed1976

The histopathology of infectious bronchitis in fowls infected with a nephrotropic "T" strain of virus.

The histopathology of the infectious bronchitis caused by the Cumming "T" strain of virus is described in fowls exposed to infection by an aerosol method. Desquamation of the ciliated and glandular epithelium throughout the trachea was seen 24 hours after exposure to virus. This was followed by rapid proliferation presumably of residual basal cells with the production of a stratified undifferentiated epithelial covering. Small areas of the tracheal submucosa showed lymphocytic infiltration by the 4th day. Cilia were first observed in the regenerating epithelium on the 7th day when mucous cells were also seen to be numerous. Alveolar mucous glands developed over the following 4 days and by the 12th day regeneration appeared complete. Pulmonary lesions were generally not severe and the air sacs were only slightly oedematous for 4 days following exposure. Necrosis of a few tubules scattered throughout the kidneys was seen on the 4th day. By the 6th day cystic tubules containing epithelial debris and polymorphonuclear leukocytes were prominent in both cortex and medulla and necrotic tubules were scattered throughout the kidneys. PAS positive granules were present in the renal tubular epithelium and were most pronounced in the distal convoluted tubules. Infiltration of the interstitium by lymphocytes and plasma cells was generally marked on the 7th day. The cytoplasm of these plasma cells was strongly PAS positive and such cells were most numerous on the 12th and 13th days after exposure and then their numbers rapidly declined. Regeneration of tubular epithelium was advanced by the 10th day and much of the cell debris had been cleared from the lumina of the tubules. What appeared to be compressed areas were seen in the cortex from the 13th day where glomeruli and tubules were numerous through considerably reduced in size. These were not seen after the 35th day, however an occasional lymph nodule persisted in the intersitium.

Animals↗
PubMed1987

Pathogenicity studies with a strain of fowl adenovirus serotype 8 (VRI-33) in chickens.

Experiments were undertaken to study the pathogenesis of VRI-33, a strain of fowl adenovirus serotype 8 isolated from the liver of a broiler chicken with inclusion body hepatitis. A 30% death rate resulted from oral infection of one-day-old specific pathogen free chickens with 10(6) plaque forming units of VRI-33. Chickens 10, 14, 21 and 28 days of age did not die following infection via natural routes but there were some motalities following infection via parenteral routes. Immunodepression by neonatal cyclophosphamide treatment, followed by infection with VRI-33 via non-parenteral routes, caused varying degrees of hepatitis with basophilic intranuclear inclusion bodies in hepatocytes. The mortality rate of cyclophosphamide-treated, VRI-33 infected chickens, was not significantly altered by post-infection temperature stress. Infection with infectious bursal disease virus, followed by infection with VRI-33 via natural routes at 14 days of age, was not associated with mortalities.

Adenoviridae↗
PubMed1983

Ventilation, gaseous exchange and air sac gases during moderate thermal panting in domestic fowl.

Gaseous exchange, ventilatory pattern and gas levels within the interclavicular and abdominal air sacs of domestic fowl were monitored before, during and after periods of moderate hyperthermic panting. O2 consumption (VO2) remained virtually unaltered and CO2 production (VCO2) increased slightly during panting as compared to normal respiration. Resting VO2 was 12.2 ml X kg-1 X min-1. Resting (eupneic) PO2 and PCO2 of the interclavicular and abdominal air sacs were 100.1 and 38.5 torr, and 125.2 and 16.4 torr respectively. During panting the partial pressure of the abdominal air sac Pabs, O2 and Pabs, CO2 fell and rose to extreme values of 109 and 29.8 torr respectively. Simultaneously the partial pressure of the interclavicular air sac Pics, O2 and Pics, CO2 changed by smaller amounts to 107.5 and 32.3 torr respectively. Ventilatory pattern during thermal panting was characterized by rapid, shallow movements which were interrupted at regular intervals by short sequences of slower, deeper breaths. During these intermittent periods of eupneic breathing gas levels returned towards normal and these alterations were reflected in transient variations in VO2 and VCO2 about their mean values. Changes in gas levels within the lung-air sac system are discussed in connexion with the peripheral control of ventilation during panting.

Acid-Base Equilibrium↗
PubMed1984

Effects of body temperature on ventilation, blood gases and acid-base balance in exercising fowl.

In order to determine the influence of hyperthermia on respiratory, blood gas and acid-base changes in exercising birds, we exercised domestic fowl on a treadmill at ambient temperatures of 5, 20, 30 and 35 degrees C for 10 min at graded running speeds up to 4.3 km.h-1. Ventilation and gas exchange were measured continuously and arterial blood gases, pH and the concentration of lactic acid in arterial blood were measured in samples taken during the last minute of each run. During exercise at 5 degrees C rectal temperature did not change significantly from rest (isothermic condition) and there was no sign of thermal influence on respiratory pattern, such as was observed at higher ambient temperatures. At any given running speed, increased ambient temperature caused increased ventilation by an increase in respiratory frequency (f) together with a decrease in tidal volume (VT). Under isothermic conditions, at low running speeds, birds maintained an isocapnic hyperpnoea: arterial PCO2, PO2 and pH and oxygen extraction were unchanged. However at higher speeds (ca. greater than 2.5 km.h-1) some hyperventilation occurred with subsequent falls in arterial PCO2 and oxygen extraction. Arterial pH also fell significantly (P less than 0.01). During hyperthermic exercise, oxygen extraction, arterial PCO2 and bicarbonate concentration all fell significantly (P less than 0.01) and progressively with increasing work load, and birds hyperventilated at all running speeds. This produced a significant arterial hypocapnia and alkalosis at the lower speeds (P less than 0.05) but this was replaced by a hypocapnic metabolic acidosis at the higher running speeds. Blood lactate concentration rose steeply at speeds above ca. 2.5 km.h-1 but arterial pH fell by only 0.1 units or less partly as a result of buffering by blood bicarbonate. It is concluded that both hyperthermia and lactacidosis are causes of hyperventilation and arterial hypocapnia during heavy running exercise in birds. However, ventilatory adjustments similar to those observed in resting hyperthermic birds, viz. increased f and reduced VT prevent severe arterial hypocapnia from occurring in hyperthermic exercising birds.

Acid-Base Equilibrium↗
PubMed1990

Respiratory responses of domestic fowl to hyperthermia following selective air sac occlusions.

Ventilation together with blood and respiratory gas tensions were measured in adult domestic fowl under normothermic and hyperthermic conditions, following bilateral occlusion of the cranial and caudal thoracic air sacs (series I) or the cranial and caudal thoracic plus the abdominal air sacs (series II). Series I birds showed no significant differences from controls. Both control and experimental animals displayed a typical thermal polypnoea combined with mild hypocapnaemia. A larger drop in PCO2 was demonstrated in the clavicular sac than in the blood, possibly indicating partial failure of inspiratory valving at the ventrobronchi. However, there was no evidence of any effect of thoracic air sac occlusion on inspiratory airflow valving in the palaeopulmo. Series II birds were strongly hypercapnaemic/hypoxaemic in normothermic conditions, with a normal minute volume, but a faster, shallower breathing pattern. During hyperthermia they increased minute ventilation 3-fold, as in control animals, and blood gas tensions were almost restored to normal. Again, there was no evidence that experimental reduction in air sac capacity, in this case up to 70% of the total, had any effect on inspiratory airflow valving in the palaeopulmo, although inevitably in this case airflow in the neopulmo was abolished.

Air Sacs↗
PubMed1968

Studies on the longitudinal muscle of the anterior mesentric artery of the domestic fowl.

1. A simple, isolated preparation is described in which the activity of the longitudinal muscle of the anterior mesenteric artery of the domestic fowl is recorded isotonically.2. The longitudinal muscle of the anterior mesenteric artery exhibited tone and marked spontaneous activity. Maximal shortening of this muscle was equal to about 60% of its resting length.3. Acetylcholine in low concentrations produced powerful contractions of the muscle, whereas low concentrations of catecholamines produced relaxation by an action on beta-receptors; much larger concentrations of adrenaline or noradrenaline contracted the muscle. A pharmacological analysis of the responses to electrical stimulation and to agonist drugs indicated that the muscle was supplied by excitatory, cholinergic nerves and by inhibitory, adrenergic nerves.

Acetylcholine↗
PubMed1968

Electrical and mechanical activity of the longitudinal muscle of the anterior mesenteric artery of the domestic fowl.

1. The electrical activity and changes in tension of the longitudinal muscle of the anterior mesenteric artery (LMAMA) of the domestic fowl were recorded simultaneously using the sucrose-gap method.2. Spontaneous activity consisted of recurring contractions each accompanied by a burst of action potentials.3. In quiescent preparations, brief electrical stimuli, acetylcholine, or barium chloride produced contractions with the appearance of action potentials. Larger concentrations of barium chloride or acetylcholine produced depolarization and action potentials ceased although contraction was maintained. Whenever depolarization without action potentials occurred, it was associated with a smooth contraction, whereas action potentials were always accompanied by small rapid contractions super-imposed upon the main contraction.4. When the tone was raised with barium chloride (and in the presence of hyoscine) continuous action potentials occurred; under these circumstances brief electrical stimuli or noradrenaline produced relaxation, cessation of action potentials, and hyperpolarization.

Acetylcholine↗
PubMed1976

Behaviour and aeration of the respiratory system in the domestic fowl embryo.

1. The monitoring of developmental stage and under-water dissection were used to examine the initial aeration of the respiratory system in domestic fowl embryos. 2. A virtually complete absence of free air within the chorioallantois was found before the beak had begun to make 'beak-clapping' movements, even when the membranes were already draped over its tip. 3. During the 'beak-clapping' stage, but before the membranes were pierced and before respiratory movements had begun, many embryos were found to contain free bubbles of air within the trachea and air sacs. 4. All embryos in which the respiratory system was aerated were found also to have froth in the crop or other parts of the digestive system. 5. Air was found in both the respiratory and digestive systems of all embryos examined after membrane penetration by the beak. 6. When air was injected into the chorioallantois before the stage of initial aeration it was recovered 5 min later from both the respiratory and digestive systems in under-water dissections. 7. It is suggested that lung ventilation takes place in the avian embryo in three distinct stages: the major air-ways become aerated, then respiratory movements begin and lastly the tertiary bronchi are slowly aerated. It is suggested also that movements involved in the imbibing of fluids play a part in aeration before the membranes are pierced.

Air↗
PubMed1983

Involvement of melatonin and thyroid hormones in the control of sleep, food intake and energy metabolism in the domestic fowl.

Growing male domestic fowl of an egg-laying strain were fed ad libitum and injected intraperitoneally with melatonin or intramuscularly with triiodothyronine (T3) to study the effects on sleep, food intake, blood glucose, e.e.g., oxygen consumption and carbon dioxide production. Melatonin caused a dose-related depression of food intake with sleep and aphagia lasting for 2 1/2 hr following 8 mg, drowsiness and greatly reduced intake following 4 and 2 mg and a slight reduction in food intake after 1 mg. T3 injection was followed by increased feeding within the range 50-200 micrograms. The higher dose (200 micrograms) completely prevented the effects of 10 mg melatonin injected simultaneously. Melatonin (10 mg) depressed plasma glucose levels whereas T3 (200 micrograms) elevated blood glucose. Either darkness or melatonin (10 mg) caused an increase in amplitude and a decrease in frequency of the e.e.g. Birds fasted for 3 hr before injection showed significantly lower oxygen consumption and carbon dioxide production when given melatonin (10 mg); T3 had no effect within the 4 hr period after injection and did not modify the effects of melatonin. It is postulated that the rapid effects of melatonin and T3 which were observed result from direct effects of these hormones on the central nervous system.

Animals↗
PubMed2005

Blood flow in guinea fowl Numida meleagris as an indicator of energy expenditure by individual muscles during walking and running.

Running and walking are mechanically complex activities. Leg muscles must exert forces to support weight and provide stability, do work to accelerate the limbs and body centre of mass, and absorb work to act as brakes. Current understanding of energy use during legged locomotion has been limited by the lack of measurements of energy use by individual muscles. Our study is based on the correlation between blood flow and aerobic energy expenditure in active skeletal muscle during locomotion. This correlation is strongly supported by the available evidence concerning control of blood flow to active muscle, and the relationship between blood flow and the rate of muscle oxygen consumption. We used injectable microspheres to measure the blood flow to the hind-limb muscles, and other body tissues, in guinea fowl (Numida meleagris) at rest, and across a range of walking and running speeds. Combined with data concerning the various mechanical functions of the leg muscles, this approach has enabled the first direct estimates of the energetic costs of some of these functions. Cardiac output increased from 350 ml min(-1) at rest, to 1700 ml min(-1) at a running speed ( approximately 2.6 m s(-1)) eliciting a of 90% of . The increase in cardiac output was achieved via approximately equal factorial increases in heart rate and stroke volume. Approximately 90% of the increased cardiac output was directed to the active muscles of the hind limbs, without redistribution of blood flow from the viscera. Values of mass-specific blood flow to the ventricles, approximately 15 ml min(-1) g(-1), and one of the hind-limb muscles, approximately 9 ml min(-1) g(-1), were the highest yet recorded for blood flow to active muscle. The patterns of increasing blood flow with increasing speed varied greatly among different muscles. The increases in flow correlated with the likely fibre type distribution of the muscles. Muscles expected to have many high-oxidative fibres preferentially increased flow at low exercise intensities. We estimated substantial energetic costs associated with swinging the limbs, co-contraction to stabilize the knee and work production by the hind-limb muscles. Our data provide a basis for evaluating hypotheses relating the mechanics and energetics of legged locomotion.

Animals↗
PubMed1975

Fowl immunoglobulins: quantitation and antibody activity during Marek's disease in genetically resistant and susceptible birds.

Five-week-old birds of resistant (N) and susceptible (P) genetic lines were inoculated with the JM strain of Marek's disease (MD) virus. MD occurred only in P-line birds; one-third had died by the end of the experiment (63 days after inoculation). Sera were examined for antibodies (precipitating, virus neutralizing,and fluorescing), and immunoglobulins were measured. Antibodies were associated with immunoglobulin classes by density gradient centrifugation and utilization of specific antisera to gowl immunoglobulins in indirect immunofluorescence. Precipitating antibodies were found in both lines; they first appeared 7 days after inoculation in P-line birds and 14 days after inoculation in N-line birds, but thereafter there was no difference between the two genetic lines. A peak of neutralizing antibody occurred in both lines between 6 and 12 days. Thereafter neutralizing antibodies increased gradually throughout the experiment. Neutralizing antibody levels were at this stage often higher in N-line than in P-line birds. The fluorescent antibody test showed transient immunoglobulin (Ig) M antibody from 7 to 9 days in N-line birds and 5 to 12 days in P-line birds; this corresponded with the initial peak of neutralizing antibody. Antibodies were seen from 7 to 8 days after inoculation and increased gradually durin gthe experiment, generally paralleling the secondary increase in neutralizing antibodies. Ultracentrifugation confirmed the presence of IgM and IgG antibodies as described. Antibodies of the IgA class were not found. The alterations in serum immunoglobulin levels occurred in three phrases: (i) 1 to 9 days postinfection, there was an increase in IgM and IgA compared with uninfected control birds; (ii) 10 to 20 days postinfection, Ig M and IgA levels were lower than in control birds; and (iii) 21 days postinfection, until the end of experiment, IgA returned to normal levels, IgG increased to about eight times higher than in control birds, and IgM in P-line birds returned to normal levels and in N-line birds reached and maintained levels about double those of control birds. Another experiment was designed to examine the separate effects of moving and inoculation of uninfected kidney cells and virus-infected kidney cells. The changes in immunoglobulins observed in the first experiment occurred only after infection with MD virus and were not related to movement or handling stress. It was concluded that no significant primary difference exists in the humoral immune system between fowls resistant and susceptible to MD; all differences could be related to the immunosuppressive effects of MD, which are greater in susceptible birds apparently due to the greater lymphoid tissue damage in these strains.

Animals↗
PubMed2001

Role of capsule in the pathogenesis of fowl cholera caused by Pasteurella multocida serogroup A.

We have constructed a defined acapsular mutant in Pasteurella multocida X-73 (serogroup A:1) by disrupting the hexA gene through the insertion of a tetracycline resistance cassette. The genotype of the hexA::tet(M) strain was confirmed by PCR and Southern hybridization, and the acapsular phenotype of this strain was confirmed by electron microscopy. The hexA::tet(M) strain was attenuated in both mice and chickens. Complementation of the mutant with an intact hexAB fragment restored lethality in mice but not in chickens. In contrast to the results described previously for P. multocida serogroup B (J. D. Boyce and B. Adler, Infect. Immun. 68:3463-3468, 2000), the hexA::tet(M) strain was sensitive to the bactericidal action of chicken serum, whereas the wild-type and complemented strains were both resistant. Following inoculation into chicken muscle, the bacterial count of the hexA::tet(M) strain decreased significantly, while the wild-type and complemented strains both grew rapidly over 4 h. The capsule is thus an essential virulence determinant in the pathogenesis of fowl cholera.

Animals↗
PubMed1964

EFFECT OF SALMONELLA GALLINARUM ON CERTAIN KREBS CYCLE INTERMEDIATES OF DOMESTIC FOWL.

Freeman, B. M. (Houghton Poultry Research Station, Huntingdon, England), and L. G. Chubb. Effect of Salmonella gallinarum on certain Krebs cycle intermediates of domestic fowl. J. Bacteriol. 88:93-95. 1964.-In chickens infected with Salmonella gallinarum, the citric acid content of the blood rose but that of the liver fell significantly. The former may be due solely to anorexia; the latter is suggested to be a result of the inhibition of the reaction between pyruvic and oxaloacetic acids. Pyruvic acid in the blood remained at its normal level, suggesting that other pathways for its metabolism were being utilized. A rise in the blood alpha-ketoglutaric acid concentration was also found; this appeared to be a specific response to the infection. These results are compared with data available for other species of Salmonella.

Acetates↗
PubMed2005

Molecular epidemiology investigation of outbreaks of fowl cholera in geographically related poultry flocks.

The present work describes two cases of consecutive fowl cholera outbreak series occurring in goose and turkey flocks. Most strains isolated from epidemiologically related outbreaks showed genetic relatedness, as revealed by enterobacterial repetitive intergenic consensus-PCR and pulsed-field gel electrophoresis, suggesting that the consecutive outbreaks were due to recurrences rather than reinfections.

Animals↗
PubMed1969

Ribonucleic acid synthesis in chick embryo cells infected with fowl-plague virus.

Increases in ribonucleic acid (RNA) polymerase activity were detected in both the nuclear and ribosomal fractions of chick embryo cells infected with fowl-plague virus. These were observed only in the presence of all four nucleoside triphosphates and were not affected by actinomycin D. The RNA polymerase activity of the ribosomal fraction was shown to be associated with a component of infected cells of sedimentation coefficient approximately 70S. This component also contained infected cell-specific RNA and protein molecules.

Animals↗