198 research outputs found

    The behaviour of commercial broilers in response to a mobile robot

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    1. Modern broiler production, in increasingly large sheds holding upwards of 50.000 birds, controls indoor climate based on a handful of fixed location sensors, often well above the bird occupied zone. Significant deviations within a shed from the optimal climate conditions for the birds are common, but installing a higher density grid of fixed sensors is not cost effective. A robotic platform, moving through the flock of birds, collecting detailed spacial information on a wide range of climate parameters at bird level, will enable accurate decisions to optimise the climate in large sheds being made in real time. 2. A preliminary study investigated the feasibility of running a mobile robotic platform among a flock of broiler chickens for an entire 6-week cycle. Bird behaviour in response to the robot was also studied

    Real-time modelling of indoor particulate matter concentration in poultry houses using broiler activity and ventilation rate

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    Measuring particulate matter concentration in poultry houses remains as a difficult task, primarily because aerosol analysers are expensive, require specialist knowledge to operate and are labour intensive to maintain. However, it is well known that high concentrations of particulate matter causes health and welfare problems with livestock, farm workers and people living in the vicinity of the farm premises. In this work, a data-based mechanistic model is developed to relate broiler activity and ventilation rate with indoor particulate matter concentration. For six complete growing cycles, in a U.K. commercial poultry farm, broiler activity was monitored using a camera-based flock monitoring system (eYeNamic®) and ventilation rate was measured. Indoor particulate matter concentration was continuously monitored by measuring size-segregated mass fraction concentrations with the aerosol analyser DustTrakTM. A discrete-time multi-input single-output time-invariant parameters Transfer Function model was developed to determine the particulate dynamics within each day of the growing cycle in the poultry house using broiler activity and ventilation rate as inputs. This model monitored indoor particulate matter concentration with an average accuracy of RT2=(51±26)%. A dynamic linear regression modelling with time-variant parameters improved average accuracy with RT2=(97.7±1.3)%. It forecasted one sample-ahead the indoor particulate matter concentration level, using a time window of 14 samples, with a mean relative prediction error, MRPE=(4.6±3.2)%. Thus, dynamic modelling with time-variant parameters has the potential to be part of a control system to manage in real-time indoor particulate matter concentration in broiler houses.status: publishe

    Neural Predictive Control of Broiler Chicken Growth

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    Active control of the growth of broiler chickens has potential benefits for farmers in terms of improved production efficiency, as well as for animal welfare in terms of improved leg health. In this work, a differential recurrent neural network (DRNN) was identified from experimental data to represent broiler chicken growth using a recently developed nonlinear system identification algorithm. The DRNN model was then used as the internal model for nonlinear model predicative control (NMPC) to achieve a group of desired growth curves. The experimental results demonstrated that the DRNN model captured the underlying dynamics of the broiler growth process reasonably well. The DRNN based NMPC was able to specify feed intakes in real time so that the broiler weights accurately followed the desired growth curves ranging from −12-12% to +12% of the standard curve. The overall mean relative error between the desired and achieved broiler weight was 1.8% for the period from day 12 to day 51

    Chromatin targeting of the RNF12/RLIM E3 ubiquitin ligase controls transcriptional responses

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    Protein ubiquitylation regulates key biological processes including transcription. This isexemplified by the E3 ubiquitin ligase RNF12/RLIM, which controls developmental geneexpression by ubiquitylating the REX1 transcription factor and is mutated in an X-linkedintellectual disability disorder. However, the precise mechanisms by which ubiquitylationdrives specific transcriptional responses are not known. Here, we show that RNF12 isrecruited to specific genomic locations via a consensus sequence motif, which enables colocalisationwith REX1 substrate at gene promoters. Surprisingly, RNF12 chromatinrecruitment is achieved via a non-catalytic basic region and comprises a previouslyunappreciated N-terminal autoinhibitory mechanism. Furthermore, RNF12 chromatintargeting is critical for REX1 ubiquitylation and downstream RNF12-dependent generegulation. Our results demonstrate a key role for chromatin in regulation of the RNF12-REX1axis and provide insight into mechanisms by which protein ubiquitylation enablesprogramming of gene expression

    Effect of transportation duration of 1-day-old chicks on postplacement production performances and pododermatitis of broilers up to slaughter age

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    This experiment studied the effect of transportation duration of 1-d-old chicks on dehydration, mortality, production performance, and pododermatitis during the growout period. Eggs from the same breeder flock (Ross PM3) were collected at 35, 45, and 56 wk of age, for 3 successive identical experiments. In each experiment, newly hatched chicks received 1 of 3 transportation duration treatments from the hatchery before placement in the on-site rearing facility: no transportation corresponding to direct placement in less than 5 min (T00), or 4 (T04) or 10 h (T10) of transportation. The chicks were housed in 35-m2 pens (650 birds each) and reared until 35 d old. Hematocrit and chick BW were measured on sample chicks before and after transportation. During the growout period, bird weight, feed uptake, and feed conversion ratio were measured weekly until slaughter. Transportation duration affected BW; T00 groups had a significantly higher BW than T04 and T10 transported birds but this effect lasted only until d 21. No clear effect on hematocrit, feed uptake, feed conversion ratio, or mortality was observed for birds transported up to 10 h. The decrease in weight in T10 birds was associated with less severe pododermatitis. Increasing age of the breeder flock was correlated with reduced egg fertility and hatchability, and also with higher quality and BW of hatched chicks. Chicks from older breeders also exhibited reduced mortality during the growout period

    Methods for measuring gas emissions from naturally ventilated livestock buildings: Developments over the last decade and perspectives for improvement

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    [EN] The objectives of this paper are: 1) to give an overview of the development of methods for measuring emission rates from naturally ventilated livestock buildings over the last decade, 2) to identify and evaluate strengths and weaknesses, 3) to summarise and conclude the current state-of-art of available measurement concepts and their perspectives for improvement. The methods reviewed include determination of concentration and air exchange rate separately, tracer gas ratio, passive flux samplers, flux chambers, and combined downwind measurement and dispersion modelling. It is concluded that passive flux samplers, flux chambers and combined measurement and dispersion modelling are useful, but for limited fields of application only and require further development and validation against reference methods. The most robust method to investigate emission rates available at this stage is the tracer gas ratio method, but improvements are required. They include more detailed estimates of CO2 release rates (when using CO2 as a tracer) and research into optimising dosing performance of tracer gas release systems. The reliability of tracer gas ratio methods applied in buildings with large ventilation openings needs to be improved by a more profound understanding of tracer-pollutant ratios and their spatial variability, and the development of improved sampling methods for concentration ratios. There is a need for a field reference method against which other methods can be evaluated. None of the diicussed measurement methods can be marked as a solid reference for all conditions; tracer gas ratio methods are the most likely candidate but need further improvement. (C) 2012 IAgrE. Published by Elsevier Ltd. All rights reserved.The contribution to this paper of N. Ogink and J. Mosquera was financially supported by the Netherlands Ministry of Infrastructure and Environment.Ogink, NWM.; Mosquera, J.; Calvet Sanz, S.; Zhang, G. (2013). Methods for measuring gas emissions from naturally ventilated livestock buildings: Developments over the last decade and perspectives for improvement. Biosystems Engineering. 116(3):297-308. https://doi.org/10.1016/j.biosystemseng.2012.10.005S297308116

    NLS-tagging: an alternative strategy to tag nuclear proteins

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    The characterization of transcription factor com-plexes and their binding sites in the genome by affin-ity purification has yielded tremendous new insights into how genes are regulated. The affinity purification requires either the use of antibodies raised against the factor of interest itself or by high-affinity bind-ing of a C- or N-terminally added tag sequence to the factor. Unfortunately, fusing extra amino acids to the termini of a factor can interfere with its biolog-ical function or the tag may be inaccessible inside the protein. Here, we describe an effective solution to that problem by integrating the ‘tag ’ close to the nuclear localization sequence domain of the factor. We demonstrate the effectiveness of this approach with the transcription factors Fli-1 and Irf2bp2, which cannot be tagged at their extremities without loss of function. This resulted in the identification of novel proteins partners and a new hypothesis on the con-tribution of Fli-1 to hematopoiesis

    Exportin 4 mediates a novel nuclear import pathway for Sox family transcription factors

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    SRY and other Sox-type transcription factors are important developmental regulators with various implications in human disease. In this study, we identified Exp4 (exportin 4) as an interaction partner of Sox2 in mouse embryonic stem cells and neural progenitors. We show that, besides its established function in nuclear export, Exp4 acts as a bona fide nuclear import receptor for Sox2 and SRY. Thus, Exp4 is an example of a nuclear transport receptor carrying distinct cargoes into different directions. In contrast to a published study, we observed that the import activity of Imp-α (importin-a) isoforms toward Sox2 is negligible. Instead, we found that Imp9 and the Imp-β/7 heterodimer mediate nuclear import of Sox2 in parallel to Exp4. Import signals for the three pathways overlap and include conserved residues in the Sox2 high-mobility group (HMG) box domain that are also critical for DNA binding. This suggests that nuclear import of Sox proteins is facilitated by several parallel import pathways
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