Influence of the Ni-Co/Al-Mg catalyst loading in the continuous aqueous phase reforming of the bio-oil aqueous fraction

The effect of catalyst loading in the Aqueous Phase Reforming (APR) of bio-oil aqueous fraction has been studied with a Ni-Co/Al-Mg coprecipitated catalyst. Because of the high content of water in the bio-oil aqueous fraction, APR could be a useful process to convert this fraction into valuable products. Experiments of APR with continuous feeding of aqueous solution of acetol, butanol and acetic acid as the only compound, together with a simulated and a real aqueous fraction of bio-oil, were carried out. Liquid products in the liquid effluent of the APR model compounds were quantified and the reaction pathways were revised. The increase of catalyst loading produced an increase of gas production and a gas with higher alkanes content. Acetol was the compound with the highest reactivity while the conversion of acetic acid was very low. The presence of acetic acid in the feed caused catalyst deactivation

Effects of type and level of fibre on digestive physiology and performance in reproducing and growing rabbits

The study aimed to evaluate the effect of level and type of fibre on performance and digestive traits of lactating does and growing rabbits. Two lactation diets were formulated to contain a similar level of NDF (29%): a mixture of alfalfa hay and wheat straw in diet L1 was substituted with apple pulp in diet L2. Three fattening diets were formulated: diet F1 was the same than diet L1 whereas F2 and F3 had higher level of NDF (33 and 36%, respectively) with a mixture of wheat straw and alfalfa hay in diet F2 substituted by apple pulp in diet F3. A total of 110 does and their litters were controlled during two consecutive lactations from 21 to 35 d. At weaning (35 days of age) 480 rabbits were housed collectively (four per cage) and 180 individually. Another 54 rabbits were slaughtered to determine digestive traits at 45 days of age. At 35 days of age, L1 rabbits showed 5.9 and 6.9% higher daily feed intake and body weight than L2 rabbits. In the fattening period (35 to 63 days), L1 rabbits showed a higher growth rate but a lower feed efficiency than L2 animals. In the fattening period, F1 rabbits showed a 5.9% higher weight gain and 8.8% lower feed conversion than F2 animals, whereas animals fed diet F2 had a higher weight gain (7.6%) and a worse feed conversion (6.5%) than animals fed diet F3. The highest apparent ileal digestibility of DM values was obtained for diets F1 and F3. Villi length tended to be longer (P<0.10) in animals fed the diet F1 and F3. No significant influence of treatments was detected on caecal pH, anaerobic bacteria counting or rabbit mortality (only 0.9% on average). In conclusion the substitution of a mixture of wheat straw and alfalfa hay by apple pulp in isofibrous diets increases feed efficiency but also impairs feed intake and growth rate. Furthermore, in a context of low mortality, diets with 29-30% NDF would lead to better performances in the fattening period than diets containing 33-36% NDF levels.This work was supported by a CDTI Project 04-0136.Alvarez, J.; Marguenda, I.; García-Rebollar, P.; Carabaño, R.; Blas, CD.; Corujo, A.; García-Ruiz, A. (2007). Effects of type and level of fibre on digestive physiology and performance in reproducing and growing rabbits. World Rabbit Science. 15(1):9-17. doi:10.4995/wrs.2007.61091715

Improving broiler performance at market age regardless of stocking density by using a pre-starter diet

Altres ajuts: Centro para el Desarrollo Tecnológico Industrial CDTI project IDI-20180885Broiler early nutrition has caught the attention of nutritionists due to the positive correlation between early growth rate and market weight. Early nutrition strategies such as low Ca levels or the use of highly digestible ingredients (e.g., spray-dried porcine plasma [SDPP]) have been reported to improve gut and muscle development, immunity, and overall growth of the bird. On the other hand, recent works suggested that stocking density represents the main constrain for modern chickens to express their full genetic potential. The current study aimed to elucidate the potential effects of pre-starter feeding strategies on contrasting livestock stocking densities. The study followed a factorial design of 2 contrasting starter programs (standard [0-11d] vs. pre-starter [0-4 d] + standard [4-11 d]) by 3 stocking densities (low, medium, and high, 27, 33, and 39 kg/BW/m, respectively). Birds placed at low stocking density showed higher BW and better FCR than those at high stocking density (P < 0.05) being this evident only after d 28. On the other hand, birds fed on pre-starter diet led to higher BW at 4 d (P < 0.001) and the effects on BW were maintained until market age (+2.54%; P < 0.05). The pre-starter diet also led to heavier carcasses (+2.2%; P < 0.05), improved uniformity (P < 0.10) and showed a lower incidence of lameness at high stocking densities (P < 0.05) compared to birds fed the standard starter diet. Results of the current study confirm that, regardless of the stocking density used, pre-starter diets (0-4 d) could lead to a better early growth and market weight

Effect of mineral and vitamin C mix on growth performance and blood corticosterone concentrations in heat-stressed broilers

Heat stress is a major problem in the poultry industry, especially during summer months and when birds are raised under high-density conditions. Previous studies have reported that vitamin C or electrolyte supplementation could palliate the effects of heat stress in broiler chickens. The present study evaluated the effect of a mineral and vitamin mix (AHS) added to drinking water on the performance of broiler chickens. In total, 1,824 one-day-old birds were randomly allocated to 48 pens. Maximum animal density was 26.5 kg/m2. The control group received no additive; AHS-1 and -2 groups received the AHS mix at a concentration of 1 and 2 kg/1,000 L in drinking water, respectively; and the Vit-C group received vitamin C in drinking water at 200 g/1,000 L. All birds were fed the same diets based on a 3-phase feeding program; feed and water were given on ad libitum basis. To mimic heat stress conditions, temperature in the barn was raised to 35 C from 08:00 to 14:00 h each day. For the overall growing period (0 to 35 D), adding AHS to drinking water increased final BW, ADG, and ADFI linearly (PLinear Linear 0.10). No significant effect on mortality were found (8.77%; P > 0.10). Relative to control, all the treatments tested reduced (P < 0.05) corticosterone concentration in blood serum. In conclusion, the combined use of supplementary levels of minerals and vitamins could alleviate the effects of heat stress on broilers chickens.</p

Development of simplified sampling methods for behavioural data in rabbit does

[EN] The aim of this study was to compare the results of different simplified sampling methods for behavioural data compared to reference records of 24-h in order to assess rabbit doe behaviours at different physiological stages (gestation and lactation) in animals housed in 2 types of cages (conventional and alternative). In total, we analysed 576 h of continuous video of 12 rabbit does at the end of lactation and the same females after weaning. The behavioural observations were studied using 3 independent categories of classification (location in the cage, posture and functional behaviours). Continuous behavioural recordings of 24 h were considered as the reference method to validate another 4 data collection sampling methods by aggregated video recordings of different frequency and duration [regular short and long methods with 2.4 and 8 h of observation respectively, and irregular (more frequent during the active period) short and long methods with 6 and 8 h of observation, respectively]. The current results showed that, independently of the housing system, the best method to reduce the total observation time required to assess rabbit does’ behaviour depends on the trait studied and physiological stage of the does. In gestating does, irregular methods were not suitable to estimate behaviours of long duration such as lying, sitting, resting and grooming. However, in both physiological stages, regular methods were accurate for location behaviours, postures and functional behaviours of long duration. Instead, for the study of infrequent behaviours performed mainly during dark period, where coefficients of variation were high, the irregular long method led to the lowest mean estimation errors.Alfonso-Carrillo, C.; Martín, E.; Blas, CD.; Ibáñez, M.; García-Ruiz, A.; García-Rebollar, P. (2017). Development of simplified sampling methods for behavioural data in rabbit does. World Rabbit Science. 25(1):87-94. doi:10.4995/wrs.2017.3627SWORD879425

Perpendicular magnetic anisotropy in granular multilayers of COPD alloyed nanoparticles

Co-Pd multilayers obtained by Pd capping of pre-deposited Co nanoparticles on amorphous alumina are systematically studied by means of high-resolution transmission electron microscopy, x-ray diffraction, extended x-ray absorption fine structure, SQUID-based magnetometry, and x-ray magnetic circular dichroism. The films are formed by COPD alloyed nanoparticles self-organized across the layers, with the interspace between the nanoparticles filled by the non-alloyed Pd metal. The nanoparticles show atomic arrangements compatible with short-range chemical order of L10 strucure type. The collective magnetic behavior is that of ferromagnetically coupled particles with perpendicular magnetic anisotropy, irrespective of the amount of deposited Pd. For increasing temperature three magnetic phases are identified: hard ferromagnetic with strong coercive field, soft-ferromagnetic as in an amorphous asperomagnet, and superparamagnetic. Increasing the amount of Pd in the system leads to both magnetic hardness increment and higher transition temperatures. Magnetic total moments of 1.77(4) µB and 0.45(4) µB are found at Co and Pd sites, respectively, where the orbital moment of Co, 0.40(2) µB, is high, while that of Pd is negligible. The effective magnetic anisotropy is the largest in the capping metal series (Pd, Pt, W, Cu, Ag, Au), which is attributed to the interparticle interaction between de nanoparticles, in addition to the intraparticle anisotropy arising from hybridization between the 3d-4d bands associated to the Co and Pd chemical arrangement in a L10 structure type

Perpendicular magnetic anisotropy in Co–Pt granular multilayers

Magnetization hysteresis curves have been measured on Co granular multilayers, (Al₂O₃/Co/Pt)N (N = 1 and 25), with the applied magnetic field parallel and perpendicular to the substrate plane. In all samples perpendicular magnetic anisotropy was observed. For Co particles with average diameter 3 nm, the coercive field at low temperature is μ₀HC = 0.5 T. HC decreases for increasing temperature and disappears at ≈200 K. A soft magnetic component is also present in all samples up to the freezing temperature Tf = 365 K. Co and Pt XMCD measurements at the L2,3 edges were performed, yielding to the orbital mL and spin mS contributions to the total magnetic moment of the system. These results, in addition to XANES ones, indicate the presence of CoxPt₁₋x alloy. Particles conformed of CoPt alloy, embedded in Pt and coupled magnetically by dipolar or RKKY interaction, may explain the phenomenology observed in these systems

Effect of late weaning and use of alternative cages on performance of does, suckling and fattening rabbits under extensive reproductive management

The effects of the combined use of long lactation periods (46 days) with alternative cages on the reproductive and growth performance of 104 rabbit does and their litters during five consecutive reproductive cycles were studied. Half of does were housed in conventional polyvalent cages (39 cm×100 cm×30 cm) and the other half in alternative polyvalent cages (39 cm×100 cm×60 cm), with a raised platform. Half of the rabbit does in each type of cage were weaned at 32 and the other half at 46 days after parturition. Longer lactation negatively affected the body weight (P<0.001), fat and energy content (P<0.05) of rabbit does at the end of the lactation period, but this effect decreased with the number of parturitions. Fertility, prolificacy and doe mortality were not affected by lactation length. Late weaning led to higher litter size (by 8.9%) and litter weight (by 11.3%) at the end of growing period (P<0.001) and lower feed conversion ratio per cage during the experimental period (13.5%) than weaning at 32 day (P<0.001). These results were paralleled by lower mortality (12.6 vs. 17.6%; P<0.01) of young rabbits weaned later during the overall experimental period. Differences in performance as a result of different weaning ages were only observed during cycles with worst health status (third and fifth cycles) in which late weaning decreased mortality. Type of cage did not affect doe body weight and body condition, mortality, fertility, prolificacy and litter size during the five reproductive cycles. Nevertheless, at day 21 litter weight and feed conversion ratio between 3 and 21 day were 4.2% higher (P<0.01) and 5.0% lower (P<0.05), respectively, in animals housed in alternative rather than in conventional cages. Alternative cages also led to heavier litters at 59 days (P<0.01). It was concluded that the combined use of longer lactations and cages with higher available surface with a raised platform could be alternatives to improve animal welfare in farmed rabbit

Acceptability and feasibility of a virtual community of practice to primary care professionals regarding patient empowerment : A qualitative pilot study

Background: Virtual communities of practice (vCoPs) facilitate online learning via the exchange of experiences and knowledge between interested participants. Compared to other communities, vCoPs need to overcome technological structures and specific barriers. Our objective was to pilot the acceptability and feasibility of a vCoP aimed at improving the attitudes of primary care professionals to the empowerment of patients with chronic conditions. Methods: We used a qualitative approach based on 2 focus groups: one composed of 6 general practitioners and the other of 6 practice nurses. Discussion guidelines on the topics to be investigated were provided to the moderator. Sessions were audio-recorded and transcribed verbatim. Thematic analysis was performed using the ATLAS-ti software. Results: The available operating systems and browsers and the lack of suitable spaces and time were reported as the main difficulties with the vCoP. The vCoP was perceived to be a flexible learning mode that provided up-to-date resources applicable to routine practice and offered a space for the exchange of experiences and approaches. Conclusions: The results from this pilot study show that the vCoP was considered useful for learning how to empower patients. However, while vCoPs have the potential to facilitate learning and as shown create professional awareness regarding patient empowerment, attention needs to be paid to technological and access issues and the time demands on professionals. We collected relevant inputs to improve the features, content and educational methods to be included in further vCoP implementation. Trial registration: ClinicalTrials.gov, NCT02757781. Registered on 25 April 2016