Coprological and serological diagnostic tests were compared to define the status of a pig farm with regard to Ascaris suum. On each of the 100 farms in France visited for the study, 10 blood samples were taken from pigs at the end of fattening (at least 22 weeks old) and 20 to 30 faecal samples were taken, depending on the category of animals present on the farm (10 sows, 10 piglets aged 10 to 12 weeks and 10 pigs at the end of fattening, aged at least 22 weeks). A SERASCA® ELISA test (Laboratory of Parasitology, Ghent University) was performed on each blood sample (cut-off 0.
View Article and Find Full Text PDFAlternative pig farms, which do not raise animals in closed buildings with slatted and/or concrete floors, have critical points that need particular attention. Internal parasitism is one, as the farming conditions in such structures are more favorable to the development and survival of parasites. The objectives of this study, carried out on 70 alternative farms in continental France, were to (i) estimate the frequency and level of infestation by the main internal parasites on these farms, and (ii) define their typology according to the level of parasitism.
View Article and Find Full Text PDFRecurrent coccidiosis affecting a commercial chukar partridge (Alectoris chukar) farm in Ontario, Canada was investigated. The responsible pathogenic Eimeria species was isolated for biological characterization. The uniformity of oocyst morphometrics supported that only a single Eimeria sp.
View Article and Find Full Text PDFThe sporulation of oocysts of Eimeria that infect poultry is known to be under the influence of environmental conditions, including temperature, oxygen supply, and moisture. However, even when these conditions are optimal, the level of sporulation can remain low. The effect of oocyst maturity on their ability to sporulate was investigated for two species of Eimeria: E.
View Article and Find Full Text PDFBackground: Necrotic enteritis is a significant problem to the poultry industry globally and, in Norway up to 30% of Norwegian turkey grow-outs can be affected. However, despite an awareness that differences exist between necrotic enteritis in chickens and turkeys, little information exists concerning the pathogenesis, immunity, microbiota or experimental reproduction of necrotic enteritis in turkeys. In particular, it is important to determine the appearance of the gross lesions, the age dependency of the disease and the role of netB toxin of Clostridium perfringens.
View Article and Find Full Text PDFOrganic poultry production has increased sharply with growing consumer demand in the context of sustainable development. A study was conducted in 85 organic broiler flocks between 2014 and 2015 to describe the husbandry practices and the health and welfare status of organic broilers in France, and to study farming diversity by comparing independent farms (Ind farms, = 15) with direct sales to farms working with companies (Comp farms, = 70). Each flock was visited at 3 and 11 weeks of age to collect data on farming conditions, health disorders, and mortality.
View Article and Find Full Text PDFBackground: Coccidiosis is a major parasitic disease that causes huge economic losses to the poultry industry. Its pathogenicity leads to depression of body weight gain, lesions and, in the most serious cases, death in affected animals. Genetic variability for resistance to coccidiosis in the chicken has been demonstrated and if this natural resistance could be exploited, it would reduce the costs of the disease.
View Article and Find Full Text PDFFoot-pad dermatitis (FPD) is a widespread challenge to turkey production. This study aimed at evaluating the effects of using floor heating and exposure to litter with critical moisture content (35%) under experimental infection with Eimeria. adenoeides on the severity of FPD in turkeys.
View Article and Find Full Text PDFEimeria praecox and Eimeria acervulina are two species of coccidia parasites infecting chickens, which develop in the duodenum. The purpose of this study was to evaluate the pathogenicity of E. praecox and to study interactions of this coccidium with E.
View Article and Find Full Text PDFThe aim of the present work was, after a coccidiosis outbreak in a farm rearing red-legged partridges (Alectoris rufa) in Brittany (France), to identify the Eimeria species and describe gross lesions induced by three of them (Eimeria kofoidi, Eimeria caucasica and Eimeria legionensis) after experimental infection. E. kofoidi oocysts measured 19.
View Article and Find Full Text PDFPostembedding immunogold method was used to examine the distribution of gamma-aminobutyric acid- and glycine-immunoreactives synapses on the motoneurons and primary afferent axons in frog spinal cord. Analysis of all labeled boutons on dendrites and somata of motoneurons showed that 7% were labeled for GABA, 23% only for glycine and approximately 70% were immunoreactive for both GABA and glycine. These results confirm the predominant role of glycine in postsynaptic inhibition of motoneuronal activity.
View Article and Find Full Text PDFThe distribution of immunoreactivity to the calcium-binding proteins parvalbumin, calbindin and calretinin and of cytochrome oxidase activity was studied in the mesencephalic (torus semicircularis), thalamic (nucleus reuniens) and telencephalic (ventromedial part of the anterior dorsal ventricular ridge) auditory centres of two chelonian species Emys orbicularis and Testudo horsfieldi. In the torus semicircularis, the central nucleus (core) showed intense parvalbumin immunoreactivity and high cytochrome oxidase activity, whereas the laminar nucleus (belt) showed low cytochrome oxidase activity and dense calbindin/calretinin immunoreactivity. Within the central nucleus, the central and peripheral areas could be distinguished by a higher density of parvalbumin immunoreactivity and cytochrome oxidase activity in the core than in the peripheral area.
View Article and Find Full Text PDFA centrifugal visual system showing FMRF-amide-like immunoreactivity has been demonstrated in Lampetra fluviatilis by using immunocytochemical and hodological techniques. From 50 to 60 immunoreactive neurons, labelled after contralateral intraocular injection of rhodamine beta-isothiocyanate, form a small, clearly defined, nucleus in the lateral neural plate of the magnocellular preoptic nucleus. These cells give rise to immunoreactive axons which have been observed at the base of the nucleus, in the optic chiasma and in the optic nerve, to project into the intermediate plexiform layer of the retina, which separates the layer of internal horizontal cells from the layer of external horizontal cells.
View Article and Find Full Text PDFThe ultrastructure of the retinorecipient layers of the lamprey optic tectum was analysed using tract tracing techniques combined with GABA and glutamate immunocytochemistry. Two types of neurons were identified; a population of large GABA-immunonegative cells, and a population of smaller, highly GABA-immunoreactive interneurons, some of whose dendrites contain synaptic vesicles (DCSV). Five types of axon terminals were identified and divided into two major categories.
View Article and Find Full Text PDFThe ultrastructure of the lateroventral subcomponent of the visual dorsolateral anterior thalamic nucleus of the pigeon (DLLv) was analyzed using hodological techniques and GABA-immunocytochemistry. Two types of GABA-immunonegative hyperpalliopetal neurons and a single type of strongly GABA-immunoreactive (-ir) interneuron were identified, the latter displaying long dendrites with some containing synaptic vesicles (DCSV). Ten types of axon terminal were identified and divided into two categories.
View Article and Find Full Text PDFThe nucleus rotundus of the turtles Emys orbicularis and Testudo horsfieldi was analysed by axonal tracing methods and post-embedding GABA immunocytochemistry. After injections of horseradish peroxidase or biotinylated dextran amine into the optic tectum, electron microscopic observations showed that the vast majority of ipsilateral tectorotundal axon terminals were small in size, had smooth contours and contained small, round, densely packed synaptic vesicles. These terminals were GABA-immunonegative, often gathered in clusters, and established asymmetrical synaptic contacts with either small- or medium-sized GABA-negative dendritic profiles and with GABA-immunoreactive (GABA-ir) dendrites, which did not contain synaptic vesicles.
View Article and Find Full Text PDFTransmembrane isoforms of adenylate cyclases (AC) integrate a wide variety of extracellular signals from neurotransmitters to morphogens and can also regulate cAMP production in response to calcium entry. Based on observations in the barrelless mouse strain, the Adcy1 gene (AC1) was involved in the segregation of binocular retinal inputs. To determine the potential role of other AC isoforms we localized the Adcy genes in the visual centres during development, using in situ hybridization.
View Article and Find Full Text PDFIn a recent review of the available data concerning the centrifugal visual system (CVS) of vertebrates [Repérant, J., Ward, R., Miceli, D.
View Article and Find Full Text PDFThe distribution of retinal ganglion cells (RGCs) providing input to the thalamofugal visual system in the pigeon was studied with an anatomical transneuronal transport technique using the fluorescent dye rhodamine beta-isothiocyanate (RITC). Unilateral injections of RITC made into the telencephalic visual Wulst resulted in the retrograde (1) first-order labeling (FOL) of dorsal thalamic (n. dorsolateralis anterior and n.
View Article and Find Full Text PDFThe olfactory input to the brain is carried out by olfactory nerve axons that terminate in the olfactory bulb glomeruli and make synapses onto dendrites of glutamatergic projection neurons, mitral and tufted cells, and GABAergic interneurons, periglomerular cells. The dendrites are reciprocally connected through asymmetric synapses of mitral/tufted cells with periglomerular cells and symmetric synapses of the opposite direction. Transmission at the first synapse in the olfactory pathway is regulated presynaptically, and this regulation is mediated, in part, by metabotropic GABAB receptors that, when activated, inhibit transmitter release from the olfactory nerve.
View Article and Find Full Text PDFThe present review is a detailed survey of our present knowledge of the centrifugal visual system (CVS) of vertebrates. Over the last 20 years, the use of experimental hodological and immunocytochemical techniques has led to a considerable augmentation of this knowledge. Contrary to long-held belief, the CVS is not a unique property of birds but a constant component of the central nervous system which appears to exist in all vertebrate groups.
View Article and Find Full Text PDFNeurochemical and key connectional characteristics of the anterior entopeduncular nucleus (Enta) of the turtle (Testudo horsfieldi) were studied by axonal tracing techniques and immunohistochemistry of parvalbumin, gamma-aminobutyric acid (GABA) and glutamic acid decarboxylase (GAD). We showed that the Enta, which is located within the dorsal peduncle of the lateral forebrain bundle (Pedd), has roughly topographically organized reciprocal connections with the dorsal thalamic visual nuclei, the nucleus rotundus (Rot) and dorsal lateral geniculate nucleus (GLd). The Enta receives projections from visual telencephalic areas, the anterior dorsal ventricular ridge and dorsolateral cortex/pallial thickening.
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