Prediction of metabolisable energy of poultry feeds by estimating in vitro organic matter digestibility

The aim of this study was to develop equations to predict the in vivo apparent metabolisable energy (AME) of poultry feeds using an in vitro method for estimation of organic matter digestibility. In this study, a total of 57 samples of feedstuffs and 23 samples complete diets for poultry were used. Dry matter (DM), crude protein (CP), crude fibre (CF), crude fat (CFat) and crude ash (CA) of the diets were determined. A modified method for estimating the enzymatic digestibility of organic matter (EDOM) was used. For the determination of in vivo ME, the rooster digestibility assay was followed. Obtained laboratory results, that is in vitro and proximate analysis values were regressed against the in vivo ME values and equations for predicting the in vivo ME of feeds for poultry have been derived. Using CA, CF, CFat and in vitro EDOM as predictors, the following equation for predicting the in vivo ME in poultry feeds was derived: ME (MJ/kg DM) = 5.46 – 0.2166 x CA – 0.0946 x CF + 0.2219 x CFat + 0.1054 x EDOM (R2 = 0.844, RSD = 1.10). Using only EDOM as predictor generated the equation: ME (MJ/kg DM) = -0.41 + 0.1769 x EDOM (R2 = 0.689; RSD = 1.63). Results show that using only EDOM as a predictor was not as accurate as when the other variables were included.Key words: Metabolisable energy, prediction, poultry, feeds, organic matter digestibilit

Neutrophil extracellular traps and the dysfunctional innate immune response of cystic fibrosis lung disease:a review

Abstract Background Cystic Fibrosis (CF) is a devastating genetic disease characterised primarily by unrelenting lung inflammation and infection resulting in premature death and significant morbidity. Neutrophil Extracellular Traps (NETs) are possibly key to inflammation in the disease. This review aims to draw together existing research investigating NETs in the context of a dysfunctional innate immune system in CF. Main body NETs have a limited anti-microbial role in CF and studies have shown they are present in higher numbers in CF airways and their protein constituents correlate with lung function decline. Innate immune system cells express CFTR and myeloid-specific CFTR KO mice have greater neutrophil recruitment and higher pro-inflammatory cytokine production to both sterile and bacterial inflammatory challenges. CFTR KO neutrophils have impaired anti-microbial capacity and intrinsic abnormalities in the pH of their cytoplasm, abnormal protein trafficking, increased neutrophil elastase and myeloperoxidase function, and decreased hypochlorite concentrations in their phagolysosomes. Furthermore, neutrophils from CF patients have less intrinsic apoptosis and may be therefore more likely to make NETs. CFTR KO macrophages have high intraphagolysosomal pH and increased toll-like receptor 4 on their cell surface membranes, which inhibit their anti-microbial capacity and render them hyper-responsive to inflammatory stimuli, respectively. Pharmacological treatments for CF target these intrinsic abnormalities of immune dysfunction. Emerging evidence suggests that the absence of CFTR from neutrophils affects NETosis and the interaction of NETs with macrophages. Conclusion Current evidence suggests that NETs contribute to inflammation and lung destruction rather than working effectively in their anti-microbial capacity. Further studies focussing on the pro-inflammatory nature of NET constituents are required to identify the exact mechanistic role of NETs in CF and potential therapeutic interventions

Mechanical behaviour of small load bearing structures fabricated by 3d printing

© 2019 Published by the Serbian Academic Center. 3D printing is state‐of‐the‐art manufacturing technology. In addition to prototyping, the development of this technology allows the parts produced by this technology to be used as fully functional assemblies. There are different 3D printing technologies (Fused Deposition Modeling, FDM, Selective Laser Sintering, SLS, Stereolithography, SLA and others), and different materials can be used (polymer filaments, polymer and composite powders for sintering, photopolymers). This paper presents the process of design and fabrication of small load bearing structures by FDM and verification of its mechanical properties, by using three‐point bending test. The printing parameters and setup of the three‐point bending test were analysed from aspects of flexural strength and final bending angle that was determined experimentally and by calculation

Essential oil of pinus heldreichii, needles

Needle oils of Pinus heldreichii Christ, produced from five different growth stages at two different locations in Serbia were examined for yield and composition during 1994. Although only ten components were identified in the oil, the main constituents were limonene (20.26–25.15%), germacrene D (42.6445.42%) and β-caryophyllene (10.58–13.32%). The richness of the oil in germacrene D has chemotaxonomic difference implications. © 1996, Taylor & Francis Group, LLC. All rights reserved

Volatile constituents of Achillea serbica Nym.

The volatile constituents of Achillea serbica Nym. (Asteraceae), an endemic plant of the Balkan Peninsula, has been analysed using GC and CC-MS. Fifteen identified components constituted 95.7% of the oil. The major fractions belonged to β-sabinyl acetate and camphor amounting to 39.9% and 33.9%, respectively, of the total oil content. Copyright (C) 2000 John Wiley and Sons, Ltd

Customization of electrospinning for tissue engineering

© 2018 by University of Niš, Serbia. This paper deals with two electrospinning technologies: the melt electrospinning with a customized jet head, adapted from the fused deposition modeling (FDM) 3D printer, in comparison with the standard solution electrospinning, aiming at fabrication of tissue engineering scaffolds. The resulting fibers are compared. The influence of the collector properties on those of the fabricated scaffold is investigated. The resulting electrospun fibers exhibit different characteristics such as morphology and thickness, depending on the technology. The micro-fibers are produced by the melt electrospinning with an inbuilt 3D printer jet head, whereas the solution electrospinning has produced nano-and micro-fibers. The scaffolds fabricated on the rotating drum collector exhibit a more ordered structure as well as thinner fibers than those produced on the stationary plate collector. Further investigations should aim at fabrication of porous hollow fibers and tissue engineering scaffolds with controlled porosity and properties

Friction and Adhesion in Porous Biomaterial Structure

The paper presents short review of different aspects of the introduction of porosity into the bulk biomaterial and effects on different material characteristics, especially related to friction and adhesion. Nowadays, there is a great interest to investigate relations between porosity, different mechanical responses due to controlled topography and cell responses generated accordingly. Examples of current investigations of custom developed scaffolds for tissue engineering related to cell seeding and hip stem component are shown. Friction, adhesion and adhesive forces are briefly defined as related to porous material structures and the relevance of nano- and micro- level surface layers in such structures. Patterning techniques and micro-fabrication techniques for production of controlled and random porous surface layers are given. Influence of porosity on adhesion and friction is presented through several existing experimental results. However, there is still general lack of data related to many aspects of these novel porous materials and structures

Ispitivanje prisustva specifičnih antitela protiv virusa avijarne influence kod nekih vrsta divljih ptica

Infections caused by the avian influenza virus have been known for a long time and they are present, to a smaller or greater extent, in both extensive and intensive poultry production in many parts of the world. Epidemiological investigations have established a definite significance of the population of wild birds in maintaining and spreading this infection. Avian influenza is a zoonosis, and the virus has a great potential for causing mortality in humans, in particular its subtypes H5 and H7, which is why it has lately been provoking much attention among scientists and experts, as well as the general public. The objective of the work was to catch a certain number of wild birds in several locations in the Republic of Serbia, to identify them, and to collect samples of their blood serum for the determination of specific antibodies against the avian influenza virus. Birds were caught in ten locations in a manner that was safe for the birds themselves, as well as for the staff that did the catching. The birds were caught in especially produced nets, and in some cases in special traps. The caught wild birds were identified using the methods described in reference literature. All the names of the wild birds were coordinated with the valid Serbian nomenclature of European birds, prepared by prominent ornithologist and bird lover Milan Ružić. Following catching and identification, blood samples were taken from the birds from the wing vein (in bigger birds) or from the leg vein (in smaller birds). In taking blood samples from wild birds, all the principles of asepsis and antisepsis were followed in order to prevent any possibility of infection. After that, the birds were returned to their natural habitat, to the same locations in which they were caught. Serums were isolated from the taken blood samples and they were stored at -20ºC until the final examinations. A total of 46 species of wild birds were identified among a total of 259 birds from which 259 samples of blood serum were isolated. The following were used for the detection of the presence of specific antibodies against the avian influenza virus in blood serum samples of wild birds: agar gel precipitation (AGP), the hemagglutination inhibition test (HI) for subtypes H5 and H7, the cELISA test with antigen for the A type avian infleunza virus, and the cELISA test with antigen for subtype H5 of the avian influenza virus. Due to the fact that about 360 different species of wild birds live in the Republic of Serbia, the number of 46 identified species covered by these investigations account for 12.77% of the total number of bird species present in Serbia, which is considered a good sample. Specific antibodies against the A type avian influenza virus were established in serum samples of only 9 of the 259 birds covered by examinations using the cELISA test. Of the 46 identified wild bird species, 6 belonged to birds that live exclusively in water habitats and are considered a reservoir of the avian influenza virus (white stork, mallard, mute swan, common pochard, common goldeneye, and Eurasian coot). Among the listed species, particular attention was drawn to 4 species of wild birds of the order Anseriformes and the family Anatidae (mallard, mute swan, common pochard, common goldeneye) of which there were 30 birds among the total of 259 examined. In the 30 blood serum samples of the listed bird species, specific antibodies against the A type avian influenza virus were established in 9 (30%) serum samples using cELISA. Specific antibodies against the avian influenza virus subtype H5 were established in 3 serum samples of mute swans (one serum sample originated from a mute swan which was tagged in Poland) and in one blood serum sample of a common pochard, or a total of 4 (13.33%) serum samples, using the hemagglutination inhibition test. Specific antibodies against the avian inluenza virus subtype H7 were established in 3 (10%) blood serum samples, in two serum samples from mallards and one sample from a mute swan, using the hemagglutination inhibition test. Specific antibodies against the avian influenza virus type A were not established in any examined bird species using the AGP test. In the population of wild bird species in the Republic of Serbia covered by these investigations, specific antibodies against the avian influenza virus were established only in serum samples of birds of the family Anatidae. Specific antibodies against the avian influenza virus type A established in 3 (6.52%) species of wild birds, and against subtypes H5 and H7 in 2 (4.34%) of the total of 46 examined species. The sensitivity of the cELISA test for the avian influenza virus subtype H5 and the hemagglutination inhibition test for subtype H5 amounted to 100%.Infekcije izazvane virusom avijarne influence, su već odavno poznate i prisutne u manjem ili većem obimu, kako u ekstenzivnoj, tako i u intenzivnoj živinarskoj proizvodnji, u mnogim delovima sveta. Epidemiološkim ispitivanjima je utvrđen nesumnjiv značaj populacije divljih ptica u očuvanju i širenju ove infekcije. Avijarna influenca je zoonoza, a virus ima veliki potencijal da izazove visoku smrtnost kod ljudi, posebno njegovi podtipovi H5 i H7, tako da u novije vreme izaziva veliku pažnju, kako naučne i stručne, tako i najšire javnosti. Cilj ovog rada je bio da se na nekoliko lokacija u Republici Srbiji uhvati određeni broj divljih ptica, izvrši njihova identifikacija i prikupe uzorci krvnog seruma radi otkrivanja specifičnih antitela protiv virusa avijarne influence. Hvatanje ptica vršeno je na deset lokacija na bezbedan način, kako za same ptice, tako i za osoblje koje ih je hvatalo. Hvatanje ptica obavljano je posebnim za te svrhe proizvedenim mrežama, a u nekim slučajevima i posebnim zamkama (klopkama). Za identifikaciju uhvaćenih divljih ptica korišćene su metode koje su opisane u stručnoj literaturi. Svi nazivi divljih ptica usklađeni su sa važećom srpskom nomenklaturom ptica Evrope. Nakon hvatanja i identifikacije, pticama je uzimana krv iz krilne vene (kod većih ptica) ili iz nožne vene (kod malih ptica). Prilikom uzimanja krvi od divljih ptica poštovani su svi principi asepse i antisepse, kako bi se sprečila svaka mogućnost infekcije. Nakon toga, ptice su vraćane u prirodu, na iste lokacije na kojima su i uhvaćene. Od uzetih uzoraka krvi izdvojeni su serumi koji su ostavljani na - 20ºC i čuvani do konačnog ispitivanja. Identifikovano je 46 vrsta divljih ptica sa ukupno 259 jedinki od kojih je izdvojeno 259 uzoraka krvnog seruma. Za otkrivanje prisustva specifičnih antitela protiv virusa avijarne influence u uzorcima krvnog seruma divljih ptica korišćeni su agar gel precipitacija (AGP), test inhibicije hemaglutinacije (IH) za podtipove H5 i H7, cELISA test sa antigenom A tipa virusa avijarne influence i cELISA sa antigenom podtipa H5 virusa avijarne influence. S obzirom na činjenicu da na teritoriji Republike Srbije živi oko 360 različitih vrsta divljih ptica, broj od 46 identifikovanih vrsta obuhvaćenih ispitivanjem, činio je 12,77% od ukupnog broja prisutnih vrsta ptica u Srbiji, što se smatra dobrim uzorkom. Specifična antitela protiv A tipa virusa avijarne influence ustanovljena su u uzorcima seruma samo 9 od 259 jedinki koje su bile obuhvaćene ispitivanjem primenom cELISA testa. U identifikovanih 46 vrsta divljih ptica 6 je pripadalo pticama koje žive isključivo u vodenim staništima i smatraju se rezervoarom virusa avijarne influence (bela roda, patka gluvara, labud grbac, riđoglava patka, patka dupljašica i liska). Od navedenih vrsta posebnu pažnju privukle su 4 vrste divljih ptica iz reda Anseriformes i familije Anatidae (patka gluvara, labud grbac, riđoglava patka, patka dupljašica) kojima je od ukupno 259 ptica pripadalo 30 jedinki. U 30 uzoraka krvnog seruma navedenih vrsta ptica, specifična antitela protiv A tipa virusa avijarne influence utvrđena su u 9 (30%) uzoraka seruma, primenom cELISA. Specifična antitela protiv podtipa H5 virusa avijarne influence su ustanovljena u 3 uzorka seruma labudova grbaca (jedan uzorak seruma je poticao od labuda grbca koji je prstenovan u Poljskoj) i u jednom uzorku krvnog seruma riđoglave patke, ili ukupno u 4 (13,33%) uzorka seruma, primenom testa inhibicije hemaglutinacije. Specifična antitela protiv podtipa H7 virusa avijarne influence utvrđena su u 3 (10%) uzorka krvnog seruma i to u dva seruma pataka gluvara i u jednom serumu labuda grbca, primenom inhibicije hemaglutinacije. Specifična antitela protiv A tipa virusa avijarne influence nisu ustanovljena ni kod jedne ispitivane vrste ptice, primenom AGP testa. U populaciji divljih vrta ptica u Republici Srbiji obuhvaćenih ovim ispitivanjem, specifična antitela protiv virusa avijarne influence ustanovljena su samo u uzorcima seruma ptica iz familije Anatidae. Specifična antitela protiv A tipa virusa avijarne influence su otkrivena kod 3 (6,52%) vrste divljih ptica, a protiv podtipova H5 i H7 kod 2 (4,34%) od ukupno 46 vrsta koje su ispitivane. Senzitivnost cELISA testa za podtip H5 virusa avijarne influence i testa inhibicije hemaglutinacije za isti podtip iznosila je 100%