1000 resultados para commercial laying hens


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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Daily intake of conjugated linoleic acid (CLA) has been shown to reduce body fat accumulation and to increase body metabolism; this latter effect has been often associated with the up-regulation of uncoupling proteins (UCPs). Here we addressed the effects of a CLA-supplemented murine diet (similar to 2 % CLA mixture, cis-9, trans-10 and trans-10, cis-12 isomers; 45 % of each isomer on alternating days) on mitochondrial energetics, UCP2 expression/activity in the liver and other associated morphological and functional parameters, in C57BL/6 mice. Diet supplementation with CLA reduced both lipid accumulation in adipose tissues and triacylglycerol plasma levels, but did not augment hepatic lipid storage. Livers of mice fed a diet supplemented with CLA showed high UCP2 mRNA levels and the isolated hepatic mitochondria showed indications of UCP activity: in the presence of guanosine diphosphate, the higher stimulation of respiration promoted by linoleic acid in mitochondria from the CLA mice was almost completely reduced to the level of the stimulation from the control mice. Despite the increased generation of reactive oxygen species through oxi-reduction reactions involving NAD(+)/NADH in the Krebs cycle, no oxidative stress was observed in the liver. In addition, in the absence of free fatty acids, basal respiration rates and the phosphorylating efficiency of mitochondria were preserved. These results indicate a beneficial and secure dose of CLA for diet supplementation in mice, which induces UCP2 overexpression and UCP activity in mitochondria while preserving the lipid composition and redox state of the liver.

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From September 2005 to December 2006, in order to define the prevalence of Helicobacter pullorum in broiler chickens, laying hens and turkey, a total of 365 caecum contents of animals reared in 76 different farms were collected at the slaughterhouse. A caecum content of a ostrich was also sampled. In addition, with the aim of investigating the occurrence of H. pullorum in humans, 151 faeces were collected at the Sant’Orsola-Malpighi University Hospital of Bologna from patients suffering of gastroenteritis. A modified Steele–McDermott membrane filter method was used. Gram-negative curved rod bacteria were preliminary identified as H. pullorum by a PCR assay based on 16S rRNA, then subjected to a RFLP-PCR assay to distinguish between H. pullorum and H. canadensis. One isolate from each farm was randomly selected for phenotypic characterization by biochemical methods and 1D SDSPAGE analysis of whole cell proteins profiles. Minimum Inhibitory Concentration (MIC) for seven different antibiotics were also determined by agar dilution method. Moreover, to examine the intraspecific genomic variability, two strains isolated from 17 different farms were submitted to genotyping by Pulse-Field Gel Electrophoresis (PFGE). In order to assess the molecular basis of fluorquinolone resistance in H. pullorum, gyrA of H. pullorum CIP 104787T was sequenced and nucleotide sequences of the Quinolone Resistance Determining Region (QRDR) of a total of 18 poultry isolates, with different MIC values for ciprofloxacin and nalidixic acid, were compared. According to the PCR and PCR-RFLP results, 306 out of 366 animals examined were positive for H. pullorum (83,6%) and 96,1% of farms resulted infected. All positive samples showed a high number of colonies (>50) phenotipically consistent with H. pullorum on the first isolation media, which suggests that this microrganism, when present, colonizes the poultry caecum at an elevate load. No human sample resulted positive for H. pullorum. The 1D SDS-PAGE whole protein profile analysis showed high similarity among the 74 isolates tested and with the type strain H. pullorum CIP 104787T. Regarding the MIC values, a monomodal distribution was found for ampicillin, chloramphenicol, gentamicin and nalidixic acid, whereas a bimodal trend was noticed for erythromycin, ciprofloxacin and tetracycline (indicating an acquired resistance for these antibiotics). Applying the breakpoints indicated by the CSLI, we may assume that all the H. pullorum tested are sensitive only to gentamicin. The intraspecific genomic variability observed in this study confirm that this species don’t have a clonal population structure, as motioned by other autors. The 2490 bp gyrA gene of H. pullorum CIP104787T with an Open Reading Frame (ORF) encoding a polypeptide of 829 amino acids was for the first time sequenced and characterized. All ciprofloxacin resistant poultry isolates showed ACA®ATA (Thr®Ile) substitution at codon 84 of gyrA corresponding to codons of gyrA 86, 87 and 83 of the Campylobacter jejuni, H. pylori and Escherichia coli, respectively. This substitution was functionally confirmed to be associated with the ciprofloxacin resistant phenotype of poultry isolates. This is the first report of isolation of H. pullorum in turkey and in ostrich, indicating that poultry species are the reservoir of this potential zoonotic microorganisms. In order to understand the potential role as food-borne human pathogen of H. pullorum, further studies must be carried on.

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In order to improve the animal welfare, the Council Directive 1999/74/EC (defining minimum standards for the welfare of laying hens) will ban conventional cage systems since 2012, in favour of enriched cages or floor systems. As a consequence an increased risk of bacterial contamination of eggshell is expected (EFSA, 2005). Furthermore egg-associated salmonellosis is an important public health problem throughout the world (Roberts et al., 1994). In this regard the introduction of efficient measures to reduce eggshell contamination by S. Enteritidis or other bacterial pathogens, and thus to prevent any potential or additional food safety risk for Human health, may be envisaged. The hot air pasteurization can be a viable alternative for the decontamination of the surface of the egg shell. Few studies have been performed on the decontamination power of this technique on table eggs (Hou et al, 1996; James et al., 2002). The aim of this study was to develop innovative techniques to remove surface contamination of shell eggs by hot air under natural or forced convection. Initially two simplified finite element models describing the thermal interaction between the air and egg were developed, respectively for the natural and forced convection. The numerical models were validated using an egg simulant equipped by type-K thermocouple (Chromel/Alumel). Once validated, the models allowed the selection of a thermal cycle with an inner temperature always lower than 55°C. Subsequently a specific apparatus composed by two hot air generators, one cold air generator and rolling cylinder support, was built to physically condition the eggs. The decontamination power of the thermal treatments was evaluated on shell eggs experimentally inoculated with either Salmonella Enteritidis, Escherichia coli, Listeria monocytogenes and on shell eggs containing only the indigenous microflora. The applicability of treatments was further evaluated by comparing quality traits of treated and not treated eggs immediately after the treatment and after 28 days of storage at 20°C. The results showed that the treatment characterized by two shots of hot air at 350°C for 8 sec, spaced by a cooling interval of 32 (forced convection), reduce the bacterial population of more than 90% (Salmonella enteritidis and Listeria monocytogenes). No statistically significant results were obtained comparing E. coli treated and not treated eggs as well as indigenous microflora treated and not treated eggs. A reduction of 2.6 log was observed on Salmonella enteritidis load of eggs immediately after the treatment in oven at 200°C for 200 minutes (natural convection). Furthermore no detrimental effects on quality traits of treated eggs were recorded. These results support the hot air techniques for the surface decontamination of table eggs as an effective industrial process.

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Die Gesundheitseffekte von Aerosolpartikeln werden stark von ihren chemischen und physikalischen Eigenschaften und somit den jeweiligen Bildungsprozessen und Quellencharakteristika beeinflusst. Während die Hauptquellen der anthropogenen Partikelemissionen gut untersucht sind, stellen die spezifischen Emissionsmuster zahlreicher kleiner Aerosolquellen, welche lokal und temporär zu einer signifikanten Verschlechterung der Luftqualität beitragen können, ein Forschungsdesiderat dar.rnIn der vorliegenden Arbeit werden in kombinierten Labor- und Feldmessungen durch ein integratives Analysekonzept mittels online (HR-ToF-AMS ) und filterbasierter offline (ATR-FTIR-Spektroskopie ) Messverfahren die weitgehend unbekannten physikalischen und chemischen Eigenschaften der Emissionen besonderer anthropogener Aerosolquellen untersucht. Neben einem Fußballstadion als komplexe Mischung verschiedener Aerosolquellen wie Frittieren und Grillen, Zigarettenrauchen und Pyrotechnik werden die Emissionen durch Feuerwerkskörper, landwirtschaftliche Intensivtierhaltung (Legehennen), Tief- und Straßenbauarbeiten sowie abwasserbürtige Aerosolpartikel in die Studie mit eingebunden. Die primären Partikelemissionen der untersuchten Quellen sind vorrangig durch kleine Partikelgrößen (dp < 1 µm) und somit eine hohe Lungengängigkeit gekennzeichnet. Dagegen zeigen die Aerosolpartikel im Stall der landwirtschaftlichen Intensivtierhaltung sowie die Emissionen durch die Tiefbauarbeiten einen hohen Masseanteil von Partikeln dp > 1 µm. Der Fokus der Untersuchung liegt auf der chemischen Charakterisierung der organischen Partikelbestandteile, welche für viele Quellen die NR-PM1-Emissionen dominieren. Dabei zeigen sich wichtige quellenspezifische Unterschiede in der Zusammensetzung der organischen Aerosolfraktion. Die beim Abbrand von pyrotechnischen Gegenständen freigesetzten sowie die abwasserbürtigen Aerosolpartikel enthalten dagegen hohe relative Gehalte anorganischer Substanzen. Auch können in einigen spezifischen Emissionen Metallverbindungen in den AMS-Massenspektren nachgewiesen werden. Über die Charakterisierung der Emissionsmuster und -dynamiken hinaus werden für einige verschiedenfarbige Rauchpatronen sowie die Emissionen im Stall der Intensivtierhaltung Emissionsfaktoren bestimmt, die zur quantitativen Bilanzierung herangezogen werden können. In einem weiteren Schritt werden anhand der empirischen Daten die analytischen Limitierungen der Aerosolmassenspektrometrie wie die Interferenz organischer Fragmentionen durch (Hydrogen-)Carbonate und mögliche Auswertestrategien zur Überwindung dieser Grenzen vorgestellt und diskutiert.rnEine umfangreiche Methodenentwicklung zur Verbesserung der analytischen Aussagekraft von organischen AMS-Massenspektren zeigt, dass für bestimmte Partikeltypen einzelne Fragmentionen in den AMS-Massenspektren signifikant mit ausgewählten funktionellen Molekülgruppen der FTIR-Absorptionsspektren korrelieren. Bedingt durch ihre fehlende Spezifität ist eine allgemeingültige Interpretation von AMS-Fragmentionen als Marker für verschiedene funktionelle Gruppen nicht zulässig und häufig nur durch die Ergebnisse der komplementären FTIR-Spektroskopie möglich. Des Weiteren wurde die Verdampfung und Ionisation ausgewählter Metallverbindungen im AMS analysiert. Die Arbeit verdeutlicht, dass eine qualitative und quantitative Auswertung dieser Substanzen nicht ohne Weiteres möglich ist. Die Gründe hierfür liegen in einer fehlenden Reproduzierbarkeit des Verdampfungs- und Ionisationsprozesses aufgrund von Matrixeffekten sowie der in Abhängigkeit vorangegangener Analysen (Verdampferhistorie) in der Ionisationskammer und auf dem Verdampfer statt-findenden chemischen Reaktionen.rnDie Erkenntnisse der Arbeit erlauben eine Priorisierung der untersuchten anthropogenen Quellen nach bestimmten Messparametern und stellen für deren Partikelemissionen den Ausgangpunkt einer Risikobewertung von atmosphärischen Folgeprozessen sowie potentiell negativen Auswirkungen auf die menschliche Gesundheit dar. rn

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Antimicrobial susceptibility testing was performed on a total of 581 clinical Escherichia coli isolates from diarrhea and edema disease in pigs, from acute mastitis in dairy cattle, from urinary tract infections in dogs and cats, and from septicemia in laying hens collected in Switzerland between 1999 and 2001. Among the 16 antimicrobial agents tested, resistance was most frequent for sulfonamides, tetracycline, and streptomycin. Isolates from swine presented significantly more resistance than those from the other animal species. The distribution of the resistance determinants for sulfonamides, tetracycline, and streptomycin was assessed by hybridization and PCR in resistant isolates. Significant differences in the distribution of resistance determinants for tetracycline (tetA, tetB) and sulfonamides (sulII) were observed between the isolates from swine and those from the other species. Resistance to sulfonamides could not be explained by known resistance mechanisms in more than a quarter of the sulfonamide-resistant and sulfonamide-intermediate isolates from swine, dogs and cats. This finding suggests that one or several new resistance mechanisms for sulfonamides may be widespread among E. coli isolates from these animal species. The integrase gene (intI) from class I integrons was detected in a large proportion of resistant isolates in association with the sulI and aadA genes, thus demonstrating the importance of integrons in the epidemiology of resistance in clinical E. coli isolates from animals.

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Many Member States of the European Union (EU) currently monitor antimicrobial resistance in zoonotic agents, including Salmonella and Campylobacter. According to Directive 2003/99/EC, Member States shall ensure that the monitoring provides comparable data on the occurrence of antimicrobial resistance. The European Commission asked the European Food Safety Authority to prepare detailed specifications for harmonised schemes for monitoring antimicrobial resistance. The objective of these specifications is to lay down provisions for a monitoring and reporting scheme for Salmonella in fowl (Gallus gallus), turkeys and pigs, and for Campylobacter jejuni and Campylobacter coli in broiler chickens. The current specifications are considered to be a first step towards a gradual implementation of comprehensive antimicrobial resistance monitoring at the EU level. These specifications propose to test a common set of antimicrobial agents against available cut-off values and a specified concentration range to determine the susceptibility of Salmonella and Campylobacter. Using isolates collected through programmes in which the sampling frame covers all epidemiological units of the national production, the target number of Salmonella isolates to be included in the antimicrobial resistance monitoring per Member State per year is 170 for each study population (i.e., laying hens, broilers, turkeys and slaughter pigs). The target number of Campylobacter isolates to be included in the antimicrobial resistance monitoring per Member State per year is 170 for each study population (i.e., broilers). The results of the antimicrobial resistance monitoring are assessed and reported in the yearly national report on trends and sources of zoonoses, zoonotic agents and antimicrobial resistance.

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Feather pecking in laying hens is a serious behavioral problem that is often associated with feather eating. The intake of feathers may influence the gut microbiota and its metabolism. The aim of this study was to determine the effect of 2 different diets, with or without 5% ground feathers, on the gut microbiota and the resulting microbial fermentation products and to identify keratin-degrading bacteria in chicken digesta. One-day-old Lohmann-Selected Leghorn chicks were divided into 3 feeding groups: group A (control), B (5% ground feathers in the diet), and C, in which the control diet was fed until wk 12 and then switched to the 5% feather diet to study the effect of time of first feather ingestion. The gut microbiota was analyzed by cultivation and denaturing gradient gel electrophoresis of ileum and cecum digesta. Short-chain fatty acids, ammonia, and lactate concentrations were measured as microbial metabolites. The concentration of keratinolytic bacteria increased after feather ingestion in the ileum (P < 0.001) and cecum (P = 0.033). Bacterial species that hydrolyzed keratin were identified as Enterococcus faecium, Lactobacillus crispatus, Lactobacillus reuteri-like species (97% sequence homology), and Lactobacillus salivarius-like species (97% sequence homology). Molecular analysis of cecal DNA extracts showed that the feather diet lowered the bacterial diversity indicated by a reduced richness (P < 0.001) and shannon (P = 0.012) index. The pattern of microbial metabolites indicated some changes, especially in the cecum. This study showed that feather intake induced an adaptation of the intestinal microbiota in chickens. It remains unclear to what extent the changed metabolism of the microbiota reflects the feather intake and could have an effect on the behavior of the 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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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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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.

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v. 17, n. 2, p. 206-216, abr./jun. 2016.

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Dissertação de Mestrado em Engenharia Zootécnica/Produção Animal