Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FOWLS, DOMESTIC”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,711 records · Page 95Linked to original sources
PubMed1979

Influence of the ambient acceleration field upon acute acceleration tolerance in chickens.

It has been demonstrated both in the Russian and in the American space programs that there is a progressive deconditioning of the circulatory system with exposure to weightlessness. Astronauts and cosmonauts returned to Earth have a significantly reduced orthostatic tolerance which will persist for a few days. We have measured the acceleration tolerance of domestic fowl, acutely exposed to a 6 g+z field, as the time over which a normal heart rate can be maintained. This period of circulatory accommodation ends abruptly with a marked bradycardia, which with continued treatment is terminal. For animals which have been previously chronically accelerated (e.g., physiologically adapted to a 2.5 g field) the acute acceleration tolerance is greatly increased. It appears that the influence of the ambient acceleration field in conditioning the responsiveness of the circulatory system is a general phenomenon.

Acceleration↗
PubMed2005

The role of protein kinase A and cyclin-dependent (CDC2) kinase in the control of basal and IGF-II-induced proliferation and secretory activity of chicken ovarian cells.

The aim of these experiments was to study the role of protein kinase A (PKA), cyclin-dependent kinase 2 (CDC2) and insulin-like growth factor II (IGF-II) in the control of ovarian function in domestic fowl, as well as the role of PKA and CDC2 in mediating the effects of IGF-II on the ovary. For this purpose, we studied the influence of an inhibitor of PKA (KT5720; 50 ng/ml), a CDC2 blocker (olomoucine; 1 microg/ml), IGF-II (0, 1, 10 or 100 ng/ml) and their combinations on cultured fragments of chicken ovarian follicular wall. Accumulation of PKA and CDC2 and secretion of progesterone (P4), testosterone (T), estradiol (E2) and arginine-vasotocin (AVT) were evaluated by using SDS-PAGE-Western blotting and RIA/EIA. IGF-II addition to culture medium stimulated T, E2 and AVT secretion and inhibited P4 secretion. These changes were associated with an increase in PKA and a decrease in CDC2 accumulation. The PKA blocker KT5720, when given alone, increased accumulation of PKA and secretion of T and E2, but not AVT and inhibited P4 secretion. The PKA blocker also prevented and even reversed the effects of IGF-II on PKA and steroid hormones secretion, but enhanced the action of IGF-II on AVT. The inhibitor of CDC2, olomoucine, when given alone, suppressed the expression of CDC2 and the secretion of P4 and AVT (but not T and E2). When given together with IGF-II, it augmented IGF-II-induced suppression of CDC2 and reversed the effects of IGF-II on P4 (but not on T, E2 or AVT). These observations demonstrate the involvement of PKA, CDC2 and IGF-II in regulating the secretory activity of avian ovarian cells. Our data also suggest the involvement of PKA in the mediation of IGF-II effects on P4, T, E2 and AVT secretion. CDC2 can mediate the effects of IGF-II on ovarian P4 secretion but not on other hormones.

Animals↗
PubMed2004

Light experience and the development of behavioural lateralisation in chicks. II. Choice of familiar versus unfamiliar model social partner.

In late-stage embryos of domestic fowl, exposure of the right eye to light entering through the shell induces asymmetry of the thalamofugal visual pathway, together with differences in performance according to whether the right or left eye (RE, LE) is in use (Behav. Brain Res. 38 (1990) 211). Nevertheless, at least some of the main specialisations of the right and left eye systems (RES, LES) are not dependent on such exposure. Higher ability of LES to assess and respond to novelty is present in dark-incubated (Da) chicks. This is probably also true of RES ability to control response, and specifically to inhibit shift to an alternative response (i.e. to a novel stimulus). We imprinted chicks on red table-tennis balls with a horizontal, white strip on their equator. At test, they chose between this and a ball with a vertical, white strip. Da chicks showed clear choice with the LE, but not with the RE. Unexpectedly, light-incubated (Li) chicks failed to show LE/RE differences in choice. Exploratory pecks at a novel feature were greatly reduced in Li. Two effects of light exposure on RES are likely. The first is greater use of RES in the home-cage, affecting what is learned about the companion ball. This may make RES more competent in assessing ball properties, and so explain the enhanced choice by RE, that abolished the RE/LE difference in Li. Secondly, the ability of RES to inhibit shift to an alternative response is enhanced. Light exposure and being female similarly opposed shift to the novel feature, but probably via different mechanisms. The effects of exposure are discussed as an example of the generation of a range of behavioural phenotypes, which are sustained within a single population by varying or frequency-dependent selection.

Age Factors↗
PubMed2005

The functional morphology of the english sparrow cecum.

As birds do not have a urinary bladder, the kidneys and lower gastrointestinal tract must function in concert to maintain fluid and electrolyte homeostasis. In birds, urine is conveyed to the cloaca, and moved by reverse peristalsis into the colon and digestive ceca. Digestive ceca have been well studied for non-passerine birds and have been shown to absorb substrates and water. The ceca of passerine birds have been suggested to be non-functional because of their small size. The present study was undertaken to examine the morphology and cytochemistry of the small ceca of the English sparrow (Passer domesticus). Three-dimensional reconstruction of the ceca from serially sectioned tissue showed these organs to have a central channel with a large number of side channels. Electron micrographs indicated that all of the channels are lined by epithelial cells with a very dense microvillus brush border as well as a region densely packed with mitochondria just below the brush border. Specific staining for Na(+), K(+)-ATPase indicated the enzyme to be localized to the brush border. Quantification of Na(+), K(+)-ATPase activity showed it to be comparable to the coprodeum of domestic fowl. The data suggest that the small ceca of passerine birds may function in fluid and electrolyte homeostasis.

Animals↗
PubMed2004

Ontogeny of the hypothalamo-pituitary-adrenocortical axis in the chicken embryo: a review.

The embryo of the domestic fowl (Gallus domesticus) tenders one distinctive advantage over general mammalian models for investigating the development of the hypothalamo-pituitary-adrenocortical (HPA) axis. This is the relative simplicity with which the embryonic endocrine environment can be influenced without confounding maternal influences. The ease of direct manipulation of the embryonic endocrine system has facilitated analysis of the development and function of the HPA axis in the chick embryo. As the chick embryo develops, functional activation of the adrenal gland is regulated at three different levels: the adrenal gland itself, the anterior pituitary, and the hypothalamus. The adrenal gland appears capable of independent secretion of glucocorticoids from day 8 until shortly after day 14 of embryonic development, at which point the pituitary influences adrenocortical activity. Around the same age, the hypothalamic level of control also begins. The information covered in this review will describe the major steps in the development of the HPA axis in the chicken embryo and show that the chicken has an emblematic HPA neuroendocrine axis.

Adrenal Cortex↗
PubMed2004

Anthelmintic efficacy of Flemingia vestita (Fabaceae): alterations in glucose metabolism of the cestode, Raillietina echinobothrida.

The root-tuber peel of Flemingia vestita and its active component, genistein, were tested in respect of glucose metabolism in the cestode, Raillietina echinobothrida. Live R. echinobothrida, collected from the intestine of freshly slaughtered domestic fowl, were incubated at 39+/-1 degrees C in defined concentrations of the root-peel crude extract (5 mg/ml), genistein (0.2 mg/ml) and praziquantel (1 microg/ml) in phosphate buffered saline with 1% of dimethyl sulphoxide with simultaneous maintenance of controls. In the treated worms, there was a significant decrease in the glycogen concentration accompanied with the decrease of glucose by 14-32%, whereas the malate concentration increased by 49-134% as compared to controls. Both in controls and treated parasites, however, the pyruvate content was not measurable. While alanine and lactate contents showed a decline by 7-25% in the parasites exposed to all test materials, the lactate efflux into the incubation medium showed 37-71% increase in treatments indicating an overall increase of lactate production in comparison to controls. The results showing a decline in the glycogen and glucose contents and a significant rise in the malate content and lactate efflux under treatment conditions suggest that the energy demand in the parasites possibly got enhanced under stress, though it did not influence a switch over towards aerobic degradation of glucose in the parasites.

Animals↗
PubMed2004

Systematic analysis of hematopoietic, vasculogenetic, and angiogenetic phases in the developing embryonic avian lung, Gallus gallus variant domesticus.

In the embryonic lung of the domestic fowl, Gallus gallus variant domesticus, hematogenetic and vasculogenetic cells become ultrastructurally clear from day 4 of development. In the former group of cells, filopodial extensions coalesce, cytoplasm thickens, and accumulating hemoglobin displaces the nucleus peripherally while in the latter, conspicuous filopodial extensions and large nuclei develop as the cells assume a rather stellate appearance. From day 5, erythrocytes and granular leukocytes begin forming from cytoarchitecturally cognate hematogenetic cells. The cells become distinguishable when hemoglobin starts to accumulate in the erythroblasts and electron dense bodies form in the leukoblasts. Vasculogenesis begins from day 7 in different areas of the developing lung: erthrocytes (but not granular leukocytes) appear to attract committed vasculogenetic cells (angioblasts) that form an endothelial lining and vessel wall. Arrangement of angioblasts around forming blood vessels sets the direction along which the vessels sprout (angiogenesis). In some areas of the developing lung, through what seems like an inductive erythropoietic process, arcades of erythrocytes organize. Once endothelial cells surround such continuities, discrete vascular units organize. By day 10, the major parts of the in-built (intrinsic) pulmonary vasculature are assembled. Complete pulmonary circulation (i.e., through the exchange tissue) is not established until after day 18 when the blood capillaries start to develop. Since the precursory erythrocytes do not have a respiratory role, it is imperative that de novo erythropoiesis is essential for vasculogenesis. Diffuse (fragmentary) development and subsequent piecemeal assembly of the pulmonary vascular system may explicate the fabrication of a complex circulatory architecture that grants cross-current, counter-current, and multicapillary serial arterialization designs in the exchange tissue of the avian lung. The exceptional respiratory efficiency of the avian lung is largely attributable to the geometries (physical interfacing) between the bronchial and vascular elements at different levels of morphological organization.

Animals↗
PubMed2004

RNA interference against retroviruses.

Bang and Ellerman, and later Peyton Rous, reported the first identification of transmissible cancer-causing agents, which later turned out to be avian retroviruses. Today avian retroviruses are important models for study of retrovirus replication and pathogenesis, and also important pathogens of domestic fowl. Here we describe the use of RNA interference (RNAi) in live chick embryos to block replication of an avian retrovirus. We also describe inhibition of ASLV and HIV replication in cell culture with RNAi.

Animals↗
PubMed2006

Endocrine regulation of ion transport in the avian lower intestine.

The lower intestine (colon and coprodeum) of the domestic fowl maintains a very active, transporting epithelium, with a microvillus brush border, columnar epithelial cells, and a variety of transport systems. The colon of normal or high salt-acclimated hens expresses sodium-linked glucose and amino acid cotransporters, while the coprodeum is relatively inactive. Following acclimation to low salt diets, however, both colon and coprodeum shift to a pattern of high expression of electrogenic sodium channels, and the colonic cotransporter activity is simultaneously downregulated. These changes in the transport patterns seem to be regulated, at least in part, by aldosterone. Our recent work with this tissue has focused on whether aldosterone alone can account for the low salt pattern of transport. Other work has looked at the changes in morphology and in proportions of cell types that occur during chronic acclimation to high or low salt diets, and on a cAMP-activated chloride secretion pathway. Recent findings suggesting effects of other hormones on lower intestinal transport are also presented.

Acclimatization↗
PubMed1999

The efficacy and economic benefits of Paracox, a live attenuated anticoccidial vaccine, in commercial trials with standard broiler chickens in the United Kingdom.

The first large-scale broiler trials under modern commercial conditions of Paracox, a live attenuated anticoccidial vaccine administered in the drinking-water, are reported from the United Kingdom. The vaccine, comprising all seven of the species of Eimeria that parasitise the domesticated fowl, was compared with anticoccidial drug shuttles (halofuginone then salinomycin, or nicarbazin then monensin) in nine trials comprising over 936000 chickens, all of which also received the digestive enhancer virginiamycin. No clinical diseases were diagnosed in vaccinated birds in any of the trials. Necrotic enteritis occurred in the medicated controls (anticoccidial drug shuttles) of 2/9 trials and coccidiosis occurred concurrently with one of these outbreaks. Using additional criteria that particularly reflected economic benefits, the vaccine performed overall at least as well as the drug shuttles. The crucial results for vaccinated and medicated birds were: feeding costs (pence per kg liveweight of birds that were processed), 33.9 pence (vaccinated) and 33.7 pence (medicated) (P=0.549); feed conversion ratios, 2.01 (vaccinated) and 1.96 (medicated) (P=0.025); coefficient of variation in mean bird weight before processing, 9.3% (vaccinated) and 9.0% (medicated) (P=0.300); birds found dead, 3.0% (vaccinated) and 3.8% (medicated) (P<0.001); culled birds 4.0% (vaccinated) and 3.8% (medicated) (P=0.483); birds rejected during processing, 1.1% (vaccinated) and 1.2% (medicated) (P=0.271). In addition, the mean total water consumptions per chick were 7.82 L (vaccinated) and 7.76 L (medicated) (P=0.611), whilst the mean percentages of dry matter in the litter were 76.2% (vaccinated) and 75.2% (medicated) (P=0.195). Accumulation of oocysts in the litter of chicks vaccinated at 5 days of age peaked at 21 and 35 days, compared with medicated controls which showed a single higher peak at 35 days. Hence, the use of Paracox vaccine may control clinical coccidiosis in broilers and also achieve performances at least equal to anticoccidial drugs, particularly where drug resistance might result in failure to control disease.

Animals↗
PubMed1977

Ion-exchange chromatographic study of amino acid degradation during hydrolysis of avian protein.

The losses of amino acid during acid hydrolysis of oviduct magnum protein from the domestic fowl have been measured using a Technicon TSM-1 amino acid analyser. The results were subjected to statistical analysis and a linear regression was obtained for each amino acid investigated. Methionine, in the presence of oxygen, did not exhibit significant degradation. A loss of 5.5% was found for phenylalanine after 24 h of hydrolysis under nitrogen. It is suggested that the results could be applied to animal proteins from tissue of similar composition but not to analysis of protein from plant materials.

Amino Acids↗
PubMed1981

The ontogeny of Mullerian inhibiting substance in the gonads of the chicken.

Mullerian inhibiting substance (MIS) was studied in the testis, ovary, and ovotestis of the domestic fowl, from early embryonic development to adulthood by a graded organ-culture method using the urogenital ridge of a 14.5 day fetal rat. The chick testis had high levels of MIS from 8 days of embryonic development (4-5+) until sexual maturity, when activity declined (2+) but persisted throughout adulthood. The right gonad (ovotestis) of the hen showed moderate levels of MIS activity from 8 to 12 days of embryonic life (1-3+) before its normal involution by the time of hatching (21 days). The left gonad (ovary) of the hen also produced MIS at levels similar to that seen in the testis. Activity was high during embryonic development (4+) and after hatching, and persisted in the adult hen at diminished levels (2+). MIS production by the female gonads explains regression of the right Mullerian duct, but the mechanisms that allow preservation of the left duct remain unexplained. Evidence suggests that ovarian estrogens may interact with MIS at the receptor level to protect the left Mullerian duct. MIS persists in the sexually mature gonads of both the hen and cockeral, long after the Mullerian duct has regressed, suggesting a wider role for this substance in reproductive physiology.

Age Factors↗
PubMed2002

Adrenocortical reactivity and central serotonin and dopamine turnover in young chicks from a high and low feather-pecking line of laying hens.

Feather pecking in domestic fowl is a behavioral abnormality that consists of mild or injurious pecking at feathers of conspecifics. Previously, it was shown that chicks from a high feather-pecking (HFP) and low feather-pecking (LFP) line of laying hens already differ in their propensity to feather peck at 14 and 28 days of age. As a first step in investigating a possible relationship between the development of feather pecking and physiological and neurobiological characteristics of laying hens, two subsequent experiments were carried out. Firstly, we investigated the development of adrenocortical (re)activity in HFP and LFP chicks during the first 8 weeks of life. Secondly, we studied dopamine (DA) and serotonin (5-HT) turnover in the brain of 28-day-old HFP and LFP chicks. In both experiments, chicks were exposed to manual restraint (placing the chicks on its side for 5 min). Plasma corticosterone levels were lower (baseline on Days 3 and 56; restraint-induced on Days 3, 14 and 28) in HFP chicks. Both brain DA and 5-HT turnover were lower in the HFP chicks, as well. Possible consequences for the observed differences in (stress) physiology and neurobiology between the two lines in relation to the feather pecking are discussed.

Age Factors↗
PubMed2003

Corticosterone response in the chick separation-stress paradigm.

Corticosterone response to separation stress and its sensitivity to the anxiolytic, chlordiazepoxide (CDP), were examined in 7-day-old domestic fowl (Gallus gallus). Saline or CDP (8.0 mg/kg) was injected intramuscularly 30 min before tests. Chicks were placed in isolation either with or without mirrors for a 15-min observation period, in which distress vocalizations were recorded. After testing, chicks were euthanized and blood was collected for the corticosterone assay. Chicks tested in the No-Mirror condition displayed an increase in vocalizations that was attenuated by CDP. Similarly, corticosterone levels were highest in chicks tested in the No-Mirror condition; however, CDP only modestly attenuated corticosterone levels. The present findings demonstrate that corticosterone levels parallel the behavioral marker of distress vocalizations in this paradigm, but this biological marker may be less sensitive than the behavioral marker to benzodiazepine anxiolytic manipulations.

Animals↗
PubMedDate not supplied

Radiographic monitoring of the ossification of long bones in kori (Ardeotis kori) and white-bellied (Eupodotis senegalensis) bustards.

A serial radiographic study was conducted on eight kori bustard (Ardeotis kori) and four white-bellied bustard (Eupodotis senegalensis) chicks to determine the pattern of long bone development and to establish radiographic standards for assessing skeletal maturity. The ossification pattern, appearance of secondary ossification centres, and epiphyseal fusion of the long bones in kori and white-bellied bustards were similar to those in houbara bustards (Chlamydotis undulata macqueenii), rufous-crested bustards (Eupodotis ruficrista), domestic fowl (Gallus gallus), house wrens (Troglodytes aedon aedon), racing pigeons (Columba livia). and barn owls (Tyto alba). Secondary ossification centres were present at the proximal and distal tibiotarsus, proximal tarsometatarsus and proximal metacarpal III. The ossification of long bones occurred earlier in female kori bustards compared with males.

Animals↗
PubMed1998

West Nile encephalitis epidemic in southeastern Romania.

BACKGROUND: West Nile fever (WNF) is a mosquito-borne flavivirus infection endemic in Africa and Asia. In 1996, the first major WNF epidemic in Europe occurred in Romania, with a high rate of neurological infections. We investigated the epidemic to characterise transmission patterns in this novel setting and to determine its origin. METHODS: Hospital-based surveillance identified patients admitted with acute aseptic meningitis and encephalitis in 40 Romanian districts, including Bucharest. Infection was confirmed with IgM capture and indirect IgG ELISAs. In October, 1996, we surveyed outpatients in Bucharest and seven other districts to estimate seroprevalence and to detect infected patients not admitted to hospital. We also measured the rates of infection and seropositivity in mosquitoes and birds, respectively. RESULTS: Between July 15 and Oct 12, we identified 393 patients with serologically confirmed or probable WNF infection, of whom 352 had acute central-nervous-system infections. 17 patients older than 50 years died. Fatality/case ratio and disease incidence increased with age. The outbreak was confined to 14 districts in the lower Danube valley and Bucharest (attack rate 12.4/100000 people) with a seroprevalence of 4.1%. The number of mild cases could not be estimated. WN virus was recovered from Culex pipiens mosquitoes, the most likely vector, and antibodies to WN virus were found in 41% of domestic fowl. INTERPRETATION: The epidemic in Bucharest reflected increased regional WNF transmission in 1996. Epidemics of Cx pipiens-borne WNF could occur in other European cities with conditions conducive to transmission.

Adolescent↗
PubMed2002

Light exposure of the chick embryo influences monocular sleep.

Together with some aquatic mammals, several species of birds, such as the domestic fowl, exhibit a particular behavioural and electrophysiological state called 'unihemispheric sleep', in which one cerebral hemisphere is awake and the other is sleeping. Slow-wave sleep in one hemisphere is associated with closure of the contralateral eye, whilst the eye contralateral to the awake hemisphere is open; closure of both eyes, in contrast, is associated with bihemispheric slow-wave sleep or with REM sleep. During the last few days of incubation the chick embryo is turned in the egg so that it occludes its left eye, whereas light entering through the shell can stimulate the right eye. We found that in the first 2 days after hatching chicks coming from eggs incubated in the light and reared with an imprinting object slept mostly with their right-eye open, whereas those coming from eggs incubated in the dark slept mostly with their left-eye open. In chicks reared without an imprinting object, in contrast, the effect of incubation extended over the first 2 weeks in females, with dark-incubated chicks showing more pronounced left-eye closure than light-incubated chicks, whereas the effect of incubation was similar to that observed in chicks reared with the imprinting object during the first 2 days post-hatch in males and more variable from day to day thereafter. Asymmetric light stimulation of embryos can thus modulate, though it does not generate, the left-right direction of eye opening during post-hatching monocular sleep; apparently, such a modulation depends on the emotional/motivational state of the animal associated with the outcomes of a naturally occurring visual imprinting.

Aging↗
PubMed2000

Working for a dustbath: are hens increasing pleasure rather than reducing suffering?

Dustbathing is one of the major behavioural systems of domestic fowl that is constrained by commercial caging systems. Although research conducted over the last 20 years has revealed a great deal about causation of dustbathing, attempts at measuring the importance to hens of having access to dustbathing substrate have proven difficult. Various economic techniques, operant conditioning and learning trials have been used to determine whether hens have a 'need' for dustbathing substrate or 'think' about dustbathing in the absence of substrate. In this study, we measured hens' willingness to work to obtain substrate for dustbathing using a vertically swinging door to which weights could be added. Hens were trained to push through the door to enter a goal box containing peat moss. The hens were subjected to two series of trials to compare the maximum weight that they would push to open the door when living in a cage and deprived of dustbathing substrate, with the maximum weight that they would push when living in a pen furnished with litter and a dustbath (non-deprived). Of the 10 hens that opened the door for access to peat moss, six hens pushed more weight when deprived, three hens pushed more weight when non-deprived and one hen pushed an equal amount of weight. Overall, the hens tended to push more weight (860+/-95.6 vs. 682.5+/-83.3 g; P<0.10, one-tailed paired t-test) and tended to make more attempts to open the door (P<0.10) when they were deprived than when they were non-deprived. Significantly more trials resulted in dustbathing when hens were deprived (P<0.01) suggesting that following deprivation, the hens were, in fact, more motivated to dustbathe. The results of these trials indicate that although deprived hens may be more motivated to dustbathe, and that most hens may be willing to work to obtain a dusty substrate when they can see it, they are not necessarily willing to work harder when they are in a state of deprivation than when they have recently dustbathed. These results are very difficult to explain using a 'needs' model of motivation in which deprivation leads to a state of suffering. They are much more consistent with an 'opportunity' model of motivation in which performance of the behaviour, when the opportunity presents itself, leads to a state of pleasure.

Journal Article↗