Ispitivanje mogućnosti primene imunokastracije u cilju sprečavanja mane polnog mirisa mesa nerastova

Disadvantage of meat known as boar taint is caused by steroids, androstenone being of particular importance, as well as indole and its derivatives, among which the best known is skatole. The common practice in Europe, in order to control these changes in meat, is castration without anesthesia. This intervention causes pain and stress to animals, thus undermining animal welfare. Many countries considering animal welfare try to find the alternative solutions in order to avoid castration. The alternative to surgical castration and possible solution to the problem of sex odour in the meat, as well as androstenone and skatole contents decrease in the boar's fat is immunological castration of boars (immunocastration). Average skatole content in fat tissue of boars was significantly higher (0.21±0.03 μg/g) compared to skatole content in fat tissue of the castrates, or immunocastrates (0.12±0.02 μg/g). In adipose tissue of the castrates and immunocastrates there was no significant difference in the average content of skatole. The content of androstenone in the adipose tissue of immunocastrates was below detection limits, and the average androstenone level in adipose tissue of boars was 0.66±0.13 μg/g. The obtained results show that immunocastration is justified in consideration of the meat quality and can completely replace castration in male animals, which is in compliance with the preservation of animal welfare in rearing fattening young boars.Mani mesa poznatoj kao polni miris mesa doprinose polni steroidi, od kojih je androstenon od posebnog značaja, kao i indol i njegovi derivati, među kojima je najpoznatiji skatol. Najčešća praksa u Evropi u cilju kontrole ove mane mesa je izvođenje kastracije bez anestezije. Izvođenjem ove intervencije prouzrokuje se bol i stres i narušava dobrobit životinja, što je predstavljalo podsticaj da se u mnogim zemljama, gde je poslednjih godina dobrobit životinja od velikog interesa, odustane od kastracije. Napuštanje ove metode zahteva nalaženje alternativnih rešenja u cilju otklanjanja ove mane mesa. Jedna od obećavajućih alternativa hirurškoj kastraciji i potencijalno rešenje problema polnog mirisa mesa, odnosno smanjenja sadržaja androstenona i skatola u masnom tkivu nerastova je imunološ ka kastracija (imunokastracija). Prosečan sadržaj skatola u masnom tkivu nerastova bio je značajno veći (0.21±0.03 μg/g) u odnosu na prosečan sadržaj skatola u masnom tkivu kastrata, odnosno imunokastrata (0.12±0.02 μg/g). U masnom tkivu imunokastrata i kastrata nije utvrđena razlika u prosečnom sadržaju skatola. Sadržaj androstenona u masnom tkivu imunokastrata je bio manji od granice detekcije metode, a u masnom tkivu nerastova prosečan sadržaj androstenona bio je 0.66±0.13 μg/g. Naši rezultati ukazuju da je postupak imunokastracije opravdan sa stanovišta prihvatljivosti mesa i da u potpunosti može da se zameni postupak kastracije muških jedinki, što ide u prilog očuvanju dobrobiti životinja kod uzgoja svinja za tov

The usage of 3D printing in the analysis of the product design: Case – Electronic enclosure of compact pressure transmitter

Aditivna proizvodnja uključuje izradu proizvoda složene geometrije u relativno malim količinama, kao i izradu alata i kalupa za masovnu proizvodnju. Aditivnom proizovnjom realizuju se modeli prema digitalnom prikazu, a primena je ogromna u različitim industrijskim sektorima. U poređenju sa tradicionalnom proizvodnjom, glavni parametri u odabiru aditivne tehnologije su: ušteda energije, smanjenje otpada, smanjenje upotrebe većeg broja alata, kao i optimizacija dizajna. Aditivna proizvodnja ili tehnologija 3D štampe rade na principu dodavanja materijala u slojevima, tj. model se formira od slojeva rastopljenog materijala koji se odmah hladi i očvršćava. 3D štampa omogućava čestu i jednostavnu modifikaciju modela na zahtev kupca, a pre ulaska modela u samu proizvodnju. Ovo čini komunikaciju na relaciji proizvođač-kupac dosta jednostavnom. Polazni materijal za izradu modela je polilaktična kiselina (PLA). To je ekološki termoplastični poliester koji se prirodno razgrađuje u prirodi. Na mehaničke karakteristike realizovanog modela od PLA značajno utiču različite tehnološke promenljive kao što su: prečnik brizgaljke, debljina definisanog sloja, procentualna vrednost ispune, veličina uzorka koji se puni, brzina punjenja i temperatura proizvodnje. Cilj ovog rada je da se prikaže postupak realizacije kutije elektronike za malogabaritni transmiter pritiska na 3D štampaču. Time se projektantu daje mogućnost da ispravi postojeće greške, modifikuje proizvod prema zahterima krajnjih korisnika i na kraju daje polazna osnova za realizaciju prototipa novog proizvoda.Additive manufacturing involves manufacturing of products with complex geometry in relatively small quantities, as well as the tools and molds manufacturing for mass production. With additive manufacturing, digital models are being realized and implementation is huge in various industrial sectors. Compared to traditional manufacturing, the main parameters in the choice of additive technology are: energy savings, waste reduction, reduced use of more tools and optimization of design. Additive manufacturing or 3D printing technology works on the principle of adding material in layers, i.e. the model is formed from layers of molten material that is immediately cooled and solidified. 3D printing allows to work with customers to solve design problems before embarking on a launch production. The starting material for the model is polyactic acid (PLA). It is an eco-friendly thermoplastic polyester, that breaks down naturally. The mechanical characteristics of the realized PLA model are significantly influenced by various technological variables, such as following: nozzle diameter, thickness of defined layer, percentage of fill, sample size to be filled, filling rate and production temperature. The aim of this paper is to present the process of realization of an electronics enclosure for a compact pressure transmitter on a 3D printer. This gives the designer the possibility to correct existing errors, modify the product according to the wishes of the end users and finally provides a starting point for the prototype of new product

Investigation of the efficacy of immunocastration aimed at the prevention of sex odour in boar meat

Disadvantage of meat known as boar taint is caused by steroids, androstenone being of particular importance, as well as indole and its derivatives, among which the best known is skatole. The common practice in Europe, in order to control these changes in meat, is castration without anesthesia. This intervention causes pain and stress to animals, thus undermining animal welfare. Many countries considering animal welfare try to find the alternative solutions in order to avoid castration. The alternative to surgical castration and possible solution to the problem of sex odour in the meat, as well as androstenone and skatole contents decrease in the boar's fat is immunological castration of boars (immunocastration). Average skatole content in fat tissue of boars was significantly higher (0.21±0.03 μg/g) compared to skatole content in fat tissue of the castrates, or immunocastrates (0.12±0.02 μg/g). In adipose tissue of the castrates and immunocastrates there was no significant difference in the average content of skatole. The content of androstenone in the adipose tissue of immunocastrates was below detection limits, and the average androstenone level in adipose tissue of boars was 0.66±0.13 μg/g. The obtained results show that immunocastration is justified in consideration of the meat quality and can completely replace castration in male animals, which is in compliance with the preservation of animal welfare in rearing fattening young boars