Literature update on effective environmental enrichment and light provision in broiler chickens

The results of a literature study to the effect of different types of environmental enrichment and light conditions on broiler chickens welfare are described, in order to attempt to provide an environment to slow-growing broiler chickens that better meets their behavioural requirements. With respect to environmental enrichment, a review paper has been used as a starting point and more recent information has been collected and summarised. With respect to lighting, in consultation with stakeholders we chose to limit the literature study to a fewpotential interesting areas of research (e.g. natural light provisionand its variation across the broiler house). There are several research questions in relation to enrichment provision, e.g., optimal perch design, multiple use of enrichments and the actual number of enrichments that should be provided. Currently, little is known about the need for light in slow-growing broiler chickens and how this interacts with the environmental enrichment offered. Future research priorities include theoptimization of methods of natural light provision (which is often applied in higher welfare indoor systems with slow-growing breeds), testing effects of ultraviolet wavelengths on chicken behaviour,and light colour preferences in slow-growing breeds

Reversible Transport of Interacting Brownian Ratchets

The transport of interacting Brownian particles in a periodic asymmetric (ratchet) substrate is studied numerically. In a zero-temperature regime, the system behaves as a reversible step motor, undergoing multiple sign reversals of the particle current as any of the following parameters are varied: the pinning potential parameters, the particle occupation number, and the excitation amplitude. The reversals are induced by successive changes in the symmetry of the effective ratchet potential produced by the substrate and the fraction of particles which are effectively pinned. At high temperatures and low frequencies, thermal noise assists delocalization of the pinned particles, rendering the system to recover net motion along the gentler direction of the substrate potential. The joint effect of high temperature and high frequency, on the other hand, induces an additional current inversion, this time favoring motion along the direction where the ratchet potential is steeper. The dependence of these properties on the ratchet parameters and particle density is analyzed in detail.Comment: 8 pages, 10 figure

Fermentation in the gut to prolong satiety : exploring mechanisms by which dietary fibres affect satiety in pigs

Obesity has become a major health problem in humans and companion animals. Although obesity is not common in farm animals, food restriction is often used to maintain low feeding costs and performance of, for instance, pregnant sows and fattening pigs. Food restriction may result in hunger and increased feeding motivation, which are associated with behavioural problems. Knowledge on the regulation of satiety is thus crucial to aid in the control of food intake in humans, and to improve welfare in food-restricted farm animals. Dietary fibres are believed to enhance satiety, but the effectiveness varies with the physicochemical properties of the fibre sources concerned. Therefore, the objective of this thesis was to identify whether and how dietary fibres with different physicochemical properties, such as bulkiness, viscosity, gelling and fermentability, affect satiety in the domestic pig, which was used both as a model for humans and as a target animal. In a study focusing on behavioural measures of satiety, pectin (viscous fibre) was the least satiating, whereas lignocellulose (bulking fibre) and resistant starch (fermentable fibre) were the most satiating fibres tested. In a subsequent study, increasing levels of guar gum, inulin, and resistant starch (all fermentable fibres), when replacing digestible starch, enhanced satiety throughout the day. Resistant starch was the most satiating fibre among all fibres tested, and used, in a subsequent study, to assess possible physiological and molecular mechanisms by which fermentation may affect satiety. Also in this study, resistant starch appeared to enhance satiety based on behavioural observations, i.e. reduced feeder-directed and drinking behaviours during 24 h. As expected, the satiating effects of resistant starch coincided with increased 24 h plasma short-chain fatty acids (SCFA) levels and decreased postprandial glucose and insulin plasma levels. Glucagon-like peptide-1 (GLP-1) plasma levels were lower in pigs fed resistant starch, whereas peptide tyrosine tyrosine (PYY) plasma levels were not affected by resistant starch, suggesting that these hormones do not play a role in the increased satiety induced by fermentation. Resistant starch consumption led to downregulation of genes involved in immune responses, and upregulation of genes involved in metabolic processes such as fatty acid and energy metabolism in the proximal colon. Moreover, correlation analysis inversely linked potential pathogenic microbial groups with plasma SCFA concentrations and with genes involved in fatty acid metabolism. These findings suggest that besides satiating effects, resistant starch has a beneficial effect on colonic health. In the last study, the long-term effects of a gelling fibre promoting satiation (alginate) and a fermentable fibre promoting satiety (resistant starch) on feeding patterns and growth performance were assessed. In the long-term, growing-finishing pigs compensated for a reduced dietary energy content by increasing voluntary food intake (alginate), or they became more efficient in the use of digestible energy (resistant starch). Moreover, dietary fibres increased the relative weight of the gastrointestinal tract and led to changes in body composition (less fat more muscle), which may be relevant for the maintenance of lean weight in humans. In conclusion, fermentable fibres are more satiating than viscous and bulking fibres. The satiating effects of fermentable fibres are likely mediated by an increased SCFA production, and a reduced and attenuated glucose supply. Under unrestricted feeding conditions, dietary fibres promoting satiation (alginate) and satiety (resistant starch) did not reduce long-term food intake and total body weight gain, yet, colon empty weight was increased and carcass growth was reduced. This implies that changes in body composition and intestinal weight or content, rather than body weight and body mass index (BMI) alone may be relevant to fully acknowledge the effects of fibres to aid in maintaining or promoting healthy body weight in humans.</p

Spin-orbit mode transfer via a classical analog of quantum teleportation

We translate the quantum teleportation protocol into a sequence of coherent operations involving three degrees of freedom of a classical laser beam. The protocol, which we demonstrate experimentally, transfers the polarisation state of the input beam to the transverse mode of the output beam. The role of quantum entanglement is played by a non-separable mode describing the path and transverse degrees of freedom. Our protocol illustrates the possibility of new optical applications based on this intriguing classical analogue of quantum entanglement.Comment: 5 pages, 7 figure

A interação entre os íons Zn(II) e Cu(II) e a catalase. um estudo voltamétrico.

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