368 resultados para Hens


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Spain produces approximately 600 M broiler chickens per year and has a current laying hen census of 35 M birds. Production of other poultry species, such as turkeys and ducks, is quite limited. The number of birds slaughtered has remained quite flat for the last 10 years although final body weight (BW) has increased in this period by almost 200g per bird. The number of laying hens has decreased markedly (e.g. circa 50 M in 2010) and the proportion of brown -egg layers has increased from less than 10% in 1990 to more than 90% in 2013. In addition to egg color, brown eggs are preferred by the consumers because of bigger size and better shell quality.

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The effects of the inclusion of raw glycerin (GLYC) and lecithin in the diet on egg production,egg quality and total tract apparent retention (TTAR) of dietary components was studied inbrown egg-laying hens from 23 to 51 wk of age. The experimental design was completelyrandomized with six diets combined as a 2 × 3 factorial with two levels of GLYC (0 vs.70 g/kg) and three animal fat to lecithin ratios (40:0, 20:20 and 0:40 g/kg). Each treatmentwas replicated eight times and the experimental unit was a cage with ten hens. Productionwas recorded by replicate every 28-d period and cumulatively. For the entire experiment,the inclusion of GLYC in the diet hindered feed conversion ratio per kilogram of eggs (2.071vs. 2.039; P < 0.05) but did not affect any of the other production or egg quality traits studied.The replacement of animal fat by lecithin (40:0, 20:20 and 0:40 g/kg) increased egg weight(60.1, 60.7 and 61.8 g, respectively; P < 0.001) and egg mass production (56.8, 57.5 and58.8 g/d, respectively; P < 0.01) and improved yolk color as measured by the DSM colorfan (9.2, 9.2 and 9.5, respectively; P < 0.001) and feed conversion ratio per kilogram of eggs(2.072, 2.068 and 2.027, respectively; P < 0.05). Feed intake, egg production and body weightgain, however, were not affected. The inclusion of GLYC in the diet did not affect nutrientretention but lecithin inclusion improved TTAR of dry matter (P < 0.05), organic matter(P < 0.05), ether extract (P < 0.001) and gross energy (P < 0.001). In summary, the inclusionof 70 g glycerol/kg diet hindered feed conversion ratio per kilogram of eggs but did notaffect any other production or digestibility trait. The replacement of animal fat by lecithinimproved egg weight, egg yolk color and nutrient digestibility. Consequently, lecithin canbe used as a lipid source in laying hen diets with beneficial effects on egg production

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We studied the influence of pre-incubation weight of eggs (EW) laid by 24 wk-old brown laying breeders on egg production from 18 (start of egg production) to 22 wk of age (average egg production across EW treatments of 87.8%). The experiment consisted in 7 treatments based on the initial EW (47 to 53 g with 1 g difference between groups) Average BW of the extreme groups varied at hatching from 32.5 to 35.4 g, respectively. Feed intake, egg production, and egg weight were recorded weekly by replicate as well as for the entire experiment (18 to 22 wk of age). Hens were weighed by replicate at the beginning and at the end of the experiment. From these data, ADFI, egg production, egg weight, egg mass, feed conversion ratio per kilogram of eggs and per dozen of eggs, and BW gain were calculated by week and for the entire experiment. Also, the number of dirty, broken, and shell-less eggs was recorded daily by replicate in all eggs produced. Data were analyzed as a completely randomized design with 7 treatments differing in the initial pre-hatching EW. Effects of EW on the variables studied were partitioned into linear and quadratic components. EW did not affect the age at which pullets reached 50% egg production, cumulative egg production, or BW gain of the hens from 18 to 22 wk of age. Egg weight and the proportion of dirty, broken, and shell-less eggs were not affected by the BW of the pullets at hatching. In summary, small eggs (>47 g) laid by young, healthy laying breeders, can be used successfully to produce high quality pullets

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Eukaryotic translation initiation factor 6 (eIF6) binds to the 60S ribosomal subunit and prevents its association with the 40S ribosomal subunit. In this paper, we devised a procedure for purifying eIF6 from rabbit reticulocyte lysates and immunochemically characterized the protein by using antibodies isolated from egg yolks of laying hens immunized with rabbit eIF6. By using these monospecific antibodies, a 1.096-kb human cDNA that encodes an eIF6 of 245 amino acids (calculated Mr 26,558) has been cloned and expressed in Escherichia coli. The purified recombinant human protein exhibits biochemical properties that are similar to eIF6 isolated from mammalian cell extracts. Database searches identified amino acid sequences from Saccharomyces cerevisiae, Drosophila, and the nematode Caenorhabditis elegans with significant identity to the deduced amino acid sequence of human eIF6, suggesting the presence of homologues of human eIF6 in these organisms.

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The so-called very low density lipoprotein receptors (VLDLRs) are related to the LDLR gene family. So far, naturally occurring mutations have only been described for the prototype LDLR; in humans, they cause familial hypercholesterolemia. Here we describe a naturally occurring mutation in a VLDLR that causes a dramatic abnormal phenotype. Hens of the mutant restricted-ovulator chicken strain carry a single mutation, lack functional oocyte receptors, are sterile, and display severe hyperlipidemia with associated premature atherosclerosis. The mutation converts a cysteine residue into a serine, resulting in an unpaired cysteine and greatly reduced expression of the mutant avian VLDLR on the oocyte surface. Extraoocytic cells in the mutant produce higher than normal amounts of a differentially spliced form of the receptor that is characteristic for somatic cells but absent from germ cells.

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Os astrovírus são agentes virais associados com enteropatias e infecções extra-intestinais em aves, ocasionando prejuízos no desenvolvimento produtivo e saúde animal. Porém, são escassos os estudos no Brasil que visem a detecção e caracterização deste vírus com maior amplitude. Nesse contexto, detectaram-se e caracterizaram-se cepas de astrovírus a partir de 60 amostras fecais de aves procedentes de diferentes criações comerciais brasileiras (postura, corte e matrizes), mediante o emprego de uma reação PanAstrovírus como triagem inicial, que consistiu numa reação de RT-hemi-nested-PCR, visando a amplificação e posterior sequenciamento de um segmento parcial do gene RdRp (RNA polimerase dependente de RNA) do gene ORF1b, uma região gênica conservada entre todos os astrovírus. Subsequentemente, nas amostras positivas na triagem, realizou-se a amplificação, clonagem e sequenciamento do gene ORF2 codificante do capsídeo viral, analisado mediante análise filogenética. Os dados obtidos demonstraram uma frequência de infecção por astrovírus em 48,3% (29/60) das amostras analisadas. As espécies virais detectadas foram as seguintes: Avastrovírus 2 (Avian Nephritis Virus, ANV) em 72,4% (21/29), Chicken Astrovírus (CAstV) em 6,8% (2/29) e Avastrovírus 1 (Turkey Astrovírus tipo 1, TAstV-1) em 20,8% (6/29) das amostras positivas. O sequenciamento total do gene ORF2 foi possível em oito amostras (8/21) positivas a ANV, em uma amostra (1/6) positiva a TAstV-1 e uma amostra (1/2) positiva para CAstV. A análise deste gene revelou, nas sequências ANV, a presença de três genótipos bem diferenciados, segundo critérios do Astroviridae Study Group, sendo que um deles, agrupou-se dentro do genótipo 5. Além disso, quando analisado com sequências procedentes de outras regiões, as sequências deste estudo formaram seis clusters, dois deles, relacionados com sequências procedentes de Austrália e Reino Unido. O análise do ORF2 em CAstV, revelou também um agrupamento com cepas procedentes do Reino Unido. Já o análise da ORF2 de TAstV-1, revelou divergência genética com cepas isoladas em Estados Unidos, que foram as únicas sequências disponíveis no GenBank. O presente estudo traz a luz vários dados epidemiológicos concernentes aos astrovírus aviário de origem brasileira o que permitirá a realização de outros estudos relacionados a epidemiologia deste vírus, seus possíveis riscos potenciais em saúde pública e a adoção de medidas de controle direcionadas a este agente

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Son tres los factores que básicamente inciden en la redefinición de la función militar en el área latinoamericana: los cambios en el escenario estratégico global; los procesos de consolidación democrática y la nueva relación entre civiles y militares; y los cambios en la política de EE.UU. hacia la región. Las fuerzas armadas expanden sus funciones a nuevos campos y surge un «neonacionalismo» que torna difícil la desmilitarización. Un debate nacional y regional sobre seguridad y el rol de las fuerzas armadas debería contribuir a una mejor articulación política e institucional del sector.

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É reconhecida a importância da avicultura para o agronegócio e para o desenvolvimento do Brasil. Mas o País tem enfrentado grande concorrência internacional, que se traduz em barreiras sanitárias e exigências cada vez maiores de controle de seu rebanho por parte dos importadores. Neste sentido, o Ministério da Agricultura, Pecuária e Abastecimento (MAPA) publicou uma série de atos legais para viabilizar a organização dos programas de saúde animal, entre eles as Instruções Normativas n° 56/2007, n° 59/2009, n°36/2012 e n°10/2013, para estabelecer os procedimentos para registro e fiscalização de estabelecimentos avícolas comerciais e de reprodução, voltados à biosseguridade do sistema avícola. Como todos os setores produtivos, a avicultura é fortemente influenciada pela sua estrutura de custos, de modo que há um certo sentimento de que a adequação às medidas de biosseguridade, preconizadas pelas normativas, pode impactar a atividade de produção de ovos comerciais de modo a levar, eventualmente, alguns avicultores ao abandono da mesma. O objetivo deste trabalho foi analisar o impacto socioeconômico das políticas sanitárias para estabelecimentos avícolas comerciais de postura da regional agropecuária de Limeira, Estado de São Paulo, analisando o perfil socioeconômico da propriedade e do produtor e, estimando o custo de produção e seu impacto em atendimento às medidas de biosseguridade preconizadas pelas normativas. Para a análise do perfil das propriedades foram utilizados os dados dos 28 estabelecimentos avícolas, levantados por meio de documentação para registro. Para a análise do perfil do produtor e para estimar os custos de produção foram considerados dez estabelecimentos, voluntários à pesquisa, visitados entre os meses de junho e julho de 2013. O resultado do estudo sugere que as adequações à biosseguridade podem ser factíveis de serem realizadas economicamente, sendo o custo relativamente pequeno frente aos possíveis riscos de enfermidades, representando entre 1,61% e 2,09% do custo total de produção. No entanto, as sucessivas alterações nas legislações podem fazer com que o programa de sanidade avícola perca a credibilidade diante da sociedade e dos produtores que demonstram resistência às mudanças nos paradigmas zoosanitários

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The optimal integration between heat and work may significantly reduce the energy demand and consequently the process cost. This paper introduces a new mathematical model for the simultaneous synthesis of heat exchanger networks (HENs) in which the pressure levels of the process streams can be adjusted to enhance the heat integration. A superstructure is proposed for the HEN design with pressure recovery, developed via generalized disjunctive programming (GDP) and mixed-integer nonlinear programming (MINLP) formulation. The process conditions (stream temperature and pressure) must be optimized. Furthermore, the approach allows for coupling of the turbines and compressors and selection of the turbines and valves to minimize the total annualized cost, which consists of the operational and capital expenses. The model is tested for its applicability in three case studies, including a cryogenic application. The results indicate that the energy integration reduces the quantity of utilities required, thus decreasing the overall cost.

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The optimal integration of work and its interaction with heat can represent large energy savings in industrial plants. This paper introduces a new optimization model for the simultaneous synthesis of work exchange networks (WENs), with heat integration for the optimal pressure recovery of process gaseous streams. The proposed approach for the WEN synthesis is analogous to the well-known problem of synthesis of heat exchanger networks (HENs). Thus, there is work exchange between high-pressure (HP) and low-pressure (LP) streams, achieved by pressure manipulation equipment running on common axes. The model allows the use of several units of single-shaft-turbine-compressor (SSTC), as well as stand-alone compressors, turbines and valves. Helper motors and generators are used to respond to any demand and excess of energy. Moreover, between the WEN stages the streams are sent to the HEN to promote thermal recovery, aiming to enhance the work integration. A multi-stage superstructure is proposed to represent the process. The WEN superstructure is optimized in a mixed-integer nonlinear programming (MINLP) formulation and solved with the GAMS software, with the goal of minimizing the total annualized cost. Three examples are conducted to verify the accuracy of the proposed method. In all case studies, the heat integration between WEN stages is essential to improve the pressure recovery, and to reduce the total costs involved in the process.

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This paper introduces a new mathematical model for the simultaneous synthesis of heat exchanger networks (HENs), wherein the handling pressure of process streams is used to enhance the heat integration. The proposed approach combines generalized disjunctive programming (GDP) and mixed-integer nonlinear programming (MINLP) formulation, in order to minimize the total annualized cost composed by operational and capital expenses. A multi-stage superstructure is developed for the HEN synthesis, assuming constant heat capacity flow rates and isothermal mixing, and allowing for streams splits. In this model, the pressure and temperature of streams must be treated as optimization variables, increasing further the complexity and difficulty to solve the problem. In addition, the model allows for coupling of compressors and turbines to save energy. A case study is performed to verify the accuracy of the proposed model. In this example, the optimal integration between the heat and work decreases the need for thermal utilities in the HEN design. As a result, the total annualized cost is also reduced due to the decrease in the operational expenses related to the heating and cooling of the streams.

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This paper presents a new mathematical programming model for the retrofit of heat exchanger networks (HENs), wherein the pressure recovery of process streams is conducted to enhance heat integration. Particularly applied to cryogenic processes, HENs retrofit with combined heat and work integration is mainly aimed at reducing the use of expensive cold services. The proposed multi-stage superstructure allows the increment of the existing heat transfer area, as well as the use of new equipment for both heat exchange and pressure manipulation. The pressure recovery of streams is carried out simultaneously with the HEN design, such that the process conditions (streams pressure and temperature) are variables of optimization. The mathematical model is formulated using generalized disjunctive programming (GDP) and is optimized via mixed-integer nonlinear programming (MINLP), through the minimization of the retrofit total annualized cost, considering the turbine and compressor coupling with a helper motor. Three case studies are performed to assess the accuracy of the developed approach, including a real industrial example related to liquefied natural gas (LNG) production. The results show that the pressure recovery of streams is efficient for energy savings and, consequently, for decreasing the HEN retrofit total cost especially in sub-ambient processes.

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To improve the understanding of the development of locomotor capacity in layer hens, we measured how female laying hen chicks (n=120) of four different strains (LSL-lite, Hyline Brown, Dekalb White, Lohmann Brown; 3 groups of 10 chicks per line) utilized the ground, the air, elevated horizontal (platforms and perches) and inclined surfaces (ramps and ladders) in an aviary until 9 weeks of age. We used infra-red video recordings to perform all-occurrences sampling of locomotive behavioural and perching events that occurred on the ground—where bedding material, food and water were provided, in the air, and on elevated horizontal and inclined surfaces within weekly 30-min sampling periods. Chicks preferred level ground during the first week of life compared to weeks 5–9 (P<0.0001) and performed 52% of all behavioural events in this section. Elevated surface use began at 2 weeks of age and increased over time (P=0.003), where most behaviour was performed in S2 (45% of all events). Chicks preferred horizontal to inclined surfaces, which were used from weeks 2–5 with maximum use occurring during weeks 2 and 3. Lohmann LSL chicks used the space above the ground most frequently (P=0.05) and performed more aerial ascent/descent behaviour than other lines (P<0.0001). Overall activity levels declined with age (P<0.0001). In summary layer chicks almost exclusively locomoted on the ground but utilized elevated horizontal surfaces (perch, first platform) as early as 2 weeks. These results provide information for improving space use in rearing aviaries by introducing lower perches, platforms and ramps/ladders to accommodate age-dependent locomotor abilities.

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Factors influencing the rate of cannibalism in juvenile blue-swimmer crabs Portunus pelagicus were investigated under controlled conditions using time-lapse video recordings. This study was undertaken to improve blue-swimmer crab culture and experimentally addressed (1) prey vulnerability (2) cannibal-victim interactions, and (3) activity patterns of juveniles in varying degrees of refuge. Crabs used in the study were aged 15 weeks and sorted into two size classes; small (less than or equal to 60 mm carapace width (CW)) and large (greater than or equal to65 mm CW) of a similar sex ratio. Vulnerability and thus survival was influenced by body size variation, moult stage and refuge availability. Crabs with carapace width less than or equal to 60 mm were more vulnerable than larger individuals, as indicated by significant differences in survival rates. As predicted, juveniles in transition stages associated with ecdysis were especially vulnerable. Premoult (redliner) crabs appeared to be in a high state of agitation as evidenced by the frequency of agonistic encounters and this may be a contributing factor to the high mortality observed at this critical premoult stag. increases in refuge density increased survival of juveniles proportionally, indicating that the quantity of shelter is important for reducing cannibalism in this species. Cannibal-victim interactions were frequently asymmetrical in terms of size and moult stage. Cannibals were significantly heavier than victims, and were predominantly at intermoult stage. Sexual biases among cannibals and victims were not found in this study. Activity patterns of juveniles were influenced by the experimental conditions. Crabs provided with high refuge showed reduced aggressive activity and increased time spent resting, but unchanged locomotion or feeding activity. Regular grading as well as the presence of suitable shelter for newly moulted crabs is recommended for improving culture of P. pelagicus. Research into inducing synchronous moulting may also yield promising results. (C) 2004 Elsevier B.V. All rights reserved.