117 research outputs found

    Killing individual poultry on-farm-a survey among veterinarians and farmers

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    To date, information about reasons to select and kill poultry on-farm and which method veterinarians and poultry producers preferably use is scarce. Little is also known about their knowledge of the legislation regarding on-farm killing methods and of methods alternative to the one(s) they use, as well as their perception of those alternatives. In this study, Flemish poultry veterinarians (n = 13), broiler chicken producers (n = 27), and turkey producers (n = 4) were surveyed on killing methods they currently use in practice and alternative methods, on their opinion about what constitutes an appropriate method for on-farm killing of poultry, and on their reasons for killing. All poultry veterinarians and chicken producers who filled out the survey kill poultry by manual cervical dislocation (CD), whereas some turkey farmers also indicated killing by percussive blow to the head (n = 1) or exsanguination (n = 1). Turkey producers seem to be more inclined not to kill animals with injuries or symptoms of disease as compared to veterinarians or chicken producers, such that moribund turkeys are more likely to remain in the flock. Veterinarians considered the following properties of a killing method important: animal friendliness, applicability inside the stable, a high success rate, and time efficiency. Producers ranked the properties similarly, but for them, ease of performance and cost efficiency were more important than applicability inside the stable. Producers scored those killing properties rather positively for manual as well as mechanical CD. Veterinarians and chicken producers considered the captive bolt method to be easy to perform, to have a high success rate, to be feasible to perform in the stable, and to be animal friendly. Turkey producers, however, had doubts about the latter 2 properties. Gas, injection, and electrocution were inferior methods to kill poultry according to producers. In conclusion, manual CD is the most common method for killing broiler chickens and turkeys, and knowledge of, and experience with, alternative methods is very limited, both among veterinarians and producers. Informing them about legislation and training for the use of alternative killing techniques are recommended

    Generation, Annotation and Analysis of First Large-Scale Expressed Sequence Tags from Developing Fiber of Gossypium barbadense L

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    BACKGROUND: Cotton fiber is the world's leading natural fiber used in the manufacture of textiles. Gossypium is also the model plant in the study of polyploidization, evolution, cell elongation, cell wall development, and cellulose biosynthesis. G. barbadense L. is an ideal candidate for providing new genetic variations useful to improve fiber quality for its superior properties. However, little is known about fiber development mechanisms of G. barbadense and only a few molecular resources are available in GenBank. METHODOLOGY AND PRINCIPAL FINDINGS: In total, 10,979 high-quality expressed sequence tags (ESTs) were generated from a normalized fiber cDNA library of G. barbadense. The ESTs were clustered and assembled into 5852 unigenes, consisting of 1492 contigs and 4360 singletons. The blastx result showed 2165 unigenes with significant similarity to known genes and 2687 unigenes with significant similarity to genes of predicted proteins. Functional classification revealed that unigenes were abundant in the functions of binding, catalytic activity, and metabolic pathways of carbohydrate, amino acid, energy, and lipids. The function motif/domain-related cytoskeleton and redox homeostasis were enriched. Among the 5852 unigenes, 282 and 736 unigenes were identified as potential cell wall biosynthesis and transcription factors, respectively. Furthermore, the relationships among cotton species or between cotton and other model plant systems were analyzed. Some putative species-specific unigenes of G. barbadense were highlighted. CONCLUSIONS/SIGNIFICANCE: The ESTs generated in this study are from the first large-scale EST project for G. barbadense and significantly enhance the number of G. barbadense ESTs in public databases. This knowledge will contribute to cotton improvements by studying fiber development mechanisms of G. barbadense, establishing a breeding program using marker-assisted selection, and discovering candidate genes related to important agronomic traits of cotton through oligonucleotide array. Our work will also provide important resources for comparative genomics, polyploidization, and genome evolution among Gossypium species

    Dendritic shrinkage after injury: a cellular killer or a necessity for axonal regeneration?

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    Dendrites form an essential component of the neuronal circuit have been largely overlooked in regenerative research. Nevertheless, subtle changes in the dendritic arbors of neurons are one of the first stages of various neurodegenerative diseases, leading to dysfunctional neuronal networks and ultimately cellular death. Maintaining dendrites is therefore considered an essential neuroprotective strategy. This mini-review aims to discuss an intriguing hypothesis, which postulates that dendritic shrinkage is an important stimulant to boost axonal regeneration, and thus that preserving dendrites might not be the ideal therapeutic method to regain a full functional network upon central nervous system damage. Indeed, our study in zebrafish, a versatile animal model with robust regenerative capacity recently unraveled that dendritic retraction is evoked prior to axonal regrowth after optic nerve injury. Strikingly, inhibiting dendritic pruning upon damage perturbed axonal regeneration. This constraining effect of dendrites on axonal regrowth has sporadically been proposed in literature, as summarized in this short narrative. In addition, the review discusses a plausible underlying mechanism for the observed antagonistic axon-dendrite interplay, which is based on energy restriction inside neurons. Axonal injury indeed leads to a high local energy demand in which efficient axonal energy supply is fundamental to ensure regrowth. At the same time, axonal lesion is known to induce mitochondrial depolarization, causing energy depletion in the axonal compartment of damaged neurons. Mitochondria, however, become mostly stationary after development, which has been proposed as a potential underlying reason for the low regenerative capacity of adult mammals. Per contra, upon reduced neuronal activity, mitochondrial mobility enhances. In this view, dendritic shrinkage after axonal injury in zebrafish could result in less synaptic input and hence, a release of mitochondria within the soma-dendrite compartment that then translocate to the axonal growth cone to stimulate axonal regeneration. If this hypothesis proofs to be correct, i.e. dendritic remodeling serving as fuel for axonal regeneration, we envision a major shift in the research focus within the neuroregenerative field and in the potential uncovering of various novel therapeutic targets

    Designing neuroreparative strategies using aged regenerating animal models

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    In our ever-aging world population, the risk of age-related neuropathies has been increasing, representing both a social and economic burden to society. Since the ability to regenerate in the adult mammalian central nervous system is very limited, brain trauma and neurodegeneration are often permanent. As a consequence, novel scientific challenges have emerged and many research efforts currently focus on triggering repair in the damaged or diseased brain. Nevertheless, stimulating neuroregeneration remains ambitious. Even though important discoveries have been made over the past decades, they did not translate into a therapy yet. Actually, this is not surprising; while these disorders mainly manifest in aged individuals, most of the research is being performed in young animal models. Aging of neurons and their environment, however, greatly affects the central nervous system and its capacity to repair. This review provides a detailed overview of the impact of aging on central nervous system functioning and regeneration potential, both in non-regenerating and spontaneously regenerating animal models. Additionally, we highlight the need for aging animal models with regenerative capacities in the search for neuroreparative strategies.status: Published onlin
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