Investigations of time and economic dimensions of the complex product production cycle

Obeležja savremene proizvodnje sa vrhunskom organizacijom i metodama upravljanja zasnivaju se na načelima ekonomije vremena i principima nove proizvodne filozofije-lean production. Proizvodnju treba organizovati po principu usisavanja, sa minimalnim zalihama, radeći samo ono što je stvarno potrebno, ni prerano ni prekasno. U radu je prikazan postupak projektovanja i rezultati istraživanja proizvodnog ciklusa složenog proizvoda koji se nalazi u proizvodnom programu kompanije 'Sloboda' Čačak.The features of contemporary production process of top organization and management methods are grounded on the principles of economies of times and the principles of lean production, a new philosophy of production. Production should be organized according to the push-pull principle, with minimum inventories, manufacturing only what is really necessary, neither too early, nor too late. The paper presents the design procedure and results of investigations on the production cycle of a complex product included in the production program of 'Sloboda' - Čačak Co

Istraživanje polimorfizma gena za κ-kazein i beta-laktoglobulin u buše i holštajnfrizijske pasmine mliječnih krava u Srbiji

The aim of this study was to determine the distribution of κ-casein (κ-CN) and β-lactoglobulin (β-Lg) genotypes in the autochtonous (Busha) and dairy (Holstein-Friesian, HF) cattle breeds with PCR-RFLP (polymerase chain reaction - restriction fragment length polymorphism). For the amplification of κ-CN and β-Lg gene fragments specific primers were used. After digestion with specific endonucleases genotypes were determined for both genes in 18 Busha and 19 HF cows. The results showed that κ-CN gene was represented with the AA genotype in 31.58 % HF cows, AB in 52.63 % cows, whilst the genotype BB was found in 15.79 % cows only. Among the examined Busha cattle 44.44 % cows had AA genotype and 55.56 % genotype AB for κ CN. As for β-Lg gene in HF breed, AA genotype was found in 26.31 % cows, AB in 63.16 % and BB in 10.53 % cows. In Busha cows the following genotypes were established for β-Lg gene: AA in 44.44 % cows and AB in 55.56 %, whilst BB genotype was not found. These results indicate that Busha cows had a higher presence of A allelic forms of both genes (k-CN and β-lactoglobulin) than HF cows.Cilj istraživanja bio je utvrditi raspodjelu genotipova kapa-kazeina (κ-CN) i beta-laktoglobulina (β-Lg) u autohtonih (buša) i mliječnih (holstein, HF) pasmina goveda primjenom PCR-RFLP. Za amplifikaciju κ-CN i β-Lg fragmenata gena korištene su specifične oligonukleotidne početnice. Nakon digestije posebnim endonukleazama (Hinf I i Hae III) genotipovi su određeni za oba gena u 18 buša i 19 HF krava. Rezultati su pokazali da je κ-CN gen utvrđen genotipom AA u 31,58 % HF krava, AB u 52,63 % krava, dok je genotip BB utvrđen u samo 15,79 % krava. Od krava pasmine buša 44,44 % je imalo AA genotip i 55,56 % genotip AB za κ-CN. Što se tiče β-Lg gena u HF pasmine, AA genotip pronađen je u 26,31 % krava, AB u 63,16 % i BB u 10,53 % krava. U krava pasmine buša sljedeći genotipovi su utvrđeni za β-Lg gen: AA u 44,44 % i AB u 55,56 % krava, dok BB genotip nije utvrđen. Ovi rezultati pokazuju da je u krava pasmine buša veća prisutnost A alelne forme za oba ispitivana gena (za k-CN i β-laktoglobulin) nego kod HF krava

Similarity of cultivars of wheat (triticum durum) on the basis of composition of gliadin alleles

Djukic N., D. Knezevic, D. Horvat, D. Zivancev and A. Torbica (2011): Similarity of cultivars of wheat (Triticum durum) on the basis of composition of gliadin alleles. - Genetika, Vol 43, No. 3, 527- 536. Twenty one durum wheat cultivars originating from different world countries were investigated. Composition of gliadins was analyzed by acid polyacrylamide gel electrophoresis. Allele composition of gliadins was determined on the basis of identified gliadin blocks. Polymorphisms of Gli-loci was established and 27 different gliadin alleles were identified, namely, 5 at Gli-A1, 4 at Gli-B1, 9 at Gli-A2 and 9 alleles at Gli-B2 locus. The catalogue of determined alleles was presented. Frequency of alleles ranged from 4.76% to 42.86%. Heterozygous Gli- loci were identified at two durum cultivars. Similarity among cultivars was studied on composition of Gli-alleles and presented by UPGMA dendogram. On the base of Gli-allele composition, similarity varied from 0% to 100%

Lab-on-a-Chip method uncertainties in determination of high-molecular- weight glutenin subunits

Polymeric wheat endosperm proteins, especially the high-molecular-weight glutenin subunits (HMW-GS), are probably the most interesting protein fraction giving the essential information about the bread-making quality of wheat flour. A relatively new method that shows great potential for a fast, reliable and automatable analysis of protein purity, sizing and quantification is microfluidic or Lab-on-a-Chip (LoaC) capillary electrophoresis. This aim of this work was to explore the possibilities of implementation of LoaC method to analysis of protein samples isolated from a Serbian common wheat variety, emphasizing the steps that might bring uncertainties and affect reproducibility of obtained glutenin subunits quantitation results. A good resolution of protein bands in a molecular weight range of 14.0 to 220.0 kDa was achieved. The reproducibility of HMW-GS sizing and quantitation were good, with the average coefficient of variation values of 1.2 and 12.2%. The ratio of HMW-GS to low-molecular-weight glutenin subunits (LMW-GS) was about 20%. The investigation ruled out influences of the extract solution addition and the buffer addition steps of the applied method, as well as the individual chip influence on GS quantitation results. However, there was statistically significant difference between HMW-GS quantitation results of multi-step and one-step extraction procedures applied prior to glutenin subunits extraction step

Genetički resursi i oplemenjivanje krmnih biljaka u Srbiji i Crnoj Gori

Review and results of research focusing on genetic resources and improvement of forage plants in Serbia and Montenegro (SMN) are presented in this paper. SMN is extremely rich on natural (native/autochthonous) genetic resources of different forage species. Great number of cultivars of perennial grass and leguminous plants as well as annual forage plants were created in SMN as a result of research work carried out over several decades. Domestic cultivars of forage plants have first of all high productive potential for yield of forage and quality of dry matter.U ovom radu dat je pregled i rezultati istraživanja na genetičkim resursima i oplemenjivanju krmnih biljaka u Srbiji i Crnoj Gori (SCG). SCG predstavlja izuzetno bogat izvor prirodnih (autohtonih) genetičkih resursa naročito vrsta krmnih biljaka. Veći broj gajenih sorti krmnih biljaka za stočnu hranu ima svoje srodnike u prirodnim livadskim zajednicama. U više decenijskom radu na oplemenjivanju krmnih biljaka stvoren je veliki broj sorti višegodišnjih trava i leguminoza i jednogodišnjih krmnih kultura sa visokim proizvodnim potencijalom za prinos krme vrlo dobrog kvaliteta suve materije

Stočni grašak - značajan faktor obezbeđenja biljnih proteina

The paper emphasizes growing and utilization of fodder pea in forage and grain production. The yield and quality of different pea varieties in forage and grain especially important in plant protein provision. The paper offers a review of areas, production, average yield of fodder pea as forage and grain crops from 1955 until the present day. Possible ways of utilization as well as access to optimal of utilization are also emphasized.U radu je razmatrana problematika gajenja i iskorišćavanja stočnog graška u proizvodnji krme i zrna. Posebno je obrađen prinos i kvalitet sortimenta stočnog graška u proizvodnji krme i zrna kao koncentrovanog stočnog hraniva, značajnog u obezbeđenju biljnih proteina. Dat je pregled kretanja površina, obima proizvodnje i prosečni prinosi po hektaru, stočnog graška za krmu i zrno od 1955. do danas (SGJ-2000), te mogući načini iskorišćavanja i optimalne faze pristupa korišćenju

Primena klasifikacije bitumena prema metodologiji Superpave u Srbiji

The paper presents new methodology for testing of rheological properties of bitumen and SUPERPAVE PG classification of bitumen based on maximum and minimum pavement design temperatures. The maps of Serbia with PG classification for different reliability levels were developed that present characteristics of bitumen that are needed for different climatic regions and different road functional classes. Paper also presents the first results of rheological tests on unmodified and modified binder used in Serbia. It was concluded that BIT 60 satisfies for high pavement design temperatures for most of Serbia and that use of modified bitumen is justified only on heavily trafficked roads or roads with slow traffic.U radu je predstavljen postupak za klasifikaciju bitumena prema metodologiji SUPERPAVE, u zavisnosti od najviših i najnižih projektnih temperatura kolovoza. Razvijene su mape za teritoriju Srbije za različite nivoe pouzdanosti, koje ukazuju na karakteristike veziva koje treba da se primeni u pojedinim klimatskim područjima i na saobraćajnicama koje pripadaju različitim funkcionalnim kategorijama. U radu su takođe prikazani i rezultati prvih ispitivanja reoloških karakteristika nemodifikovanih i modifikovanih bitumena koji se primenjuju u Srbiji i zaključeno je da BIT 60 zadovoljava u pogledu uslova primene na visokim temperaturama za najveći deo teritorije Srbije i da je primena modifikovanih bitumena opravdana samo na izuzetno opterećenim saobraćajnicama, ili saobraćajnicama sa usporenim saobraćajem

Energetska suplementacija propilen glikolom tokom peripartalnog perioda i parametri efikasnosti reprodukcije kod mlečnih krava

The aim of this work was to investigate the impact of two energy supplements based on propylene glycol in dairy cows diet on ovarian and follicular morphology, conception, insemination index and length of service period. A total number of 60 Holstein Friesian dairy cows, parity between 2-8, with an average milk production of 7000 kg/305 days of lactation were divided into three experimental groups (20 dairy cows per group). The first group of dairy cows was supplemented daily with 'Energy-plus' (O1 group; 200 mL propylene-glycol supplement) and the second group was supplemented with 'Ketal' (O2 group; 160 mL propylene-glycol supplement), two weeks before partus until 30 days post partum. The third experimental group were non supplemented dairy cows (O3, control group). Ultrasound examination of the reproductive system using real time echo camera Falco VET 100 (ESAOTE PieMedical, Holland, B-shaped scan with linear-array endorectal 5-8 MHz probe) was conducted on every animal starting from day 40 postpartum. The diameters of the ovaries (left and right) and of the dominant follicle(s) were recorded. Ultrasound testing was repeated on day 50 and 60 postpartum only in cows which in the meantime were not inseminated. Reproduction efficiency parameters (conception rate, number of inseminations and length of service period) were recorded individually. The statistical significance of the differences between groups was tested using ANOVA with LSD test at the level of significance p lt 0.05, chi-square test and Kaplan-Meier survival analysis (the length of service period). There was no significant impact of the propylene glycol supplementation on the ovarian and follicular morphology at the first ultrasound examination. At the second ultrasound examination there was a significant difference between left ovarian dominant follicle diameter in the control and supplemented dairy cows (1.67±0.53 vs 1.12±0.29 and 1.11±0.35 cm, p lt 0.05, O3 vs O1 and O2, respectively). The cumulative percentage of conception after the first and second insemination was 60%, 81% and 25% in groups O1, O2 and O3, respectively (p lt 0.05, chi-square test). The insemination index was lowest in group O2 and statistically significant differences were found between groups O2 and O3 (1.69±0.79 : 3.38±1.36, respectively, p lt 0,05). The length of the service period was significantly (p lt 0.05, LSD test) shorter in the O2 group (100±35 days) compared to groups O1 and O3 (168±59 and 157±52 days, respectively), that was confirmed by the Kaplan-Meier survival analysis of days open periods. The use of propylene glycol supplement in dairy cows diet during peripartal period induced higher percentage of pregnancy rates after the first and second insemination, significantly shortened the length of the service period and reduced the insemination index.Cilj ovog rada je bio da se ispita uticaj primene dva tipa energetskih dodataka u ishrani mlečnih krava na bazi propilen glikola na morfologiju jajnika i folikula, koncepciju, indeks osemenjavanja i dužinu servis perioda. U ogled je bilo uključeno ukupno 60 krava Holštajn Frizijske rase, u toku 2-8 laktacije, sa prosečnom proizvodnjom mleka od 7000 kg/305 dana laktacije, koje su bile podeljene u tri ogledne grupe (20 krava po grupi). Prva grupa mlečnih krava (O1) je svakodnevno suplementirana peroralnom aplikacijom 200 mL 'Energy-plus', druga grupa krava (O2) suplementirana je sa 160 mL 'Ketal-a', počevši od dve nedelje pre partusa do 30 dana nakon partusa. Treću grupu mlečnih krava (O3, kontrola) su predstavljale netretirane životinje. Ultrazvučni pregled reproduktivnog sistema vršen je sa uređajem Falco VET 100 (ESAOTE PieMedical, Holland), linearnom endorektalnom sondom od 5-8 MHz kod svake životinje najmanje dva puta počevši od 40 dana posle partusa. Ultrazvučni pregled je ponovljen sa 50 i/ili 60 dana posle partusa kod krava koje nisu u međuvremenu osemenjene. U toku svakog pregleda su registrovani prečnik oba jajnika i dominantnog folikula. Kod svake ogledne životinje su određeni parametri efikasnosti reprodukcije: stepen koncepcije, indeks osemenjavanja i servis period. Statistička značajnost razlika srednjih vrednosti dobijenih parametara određivana je ANOVA metodom i LSD testom na nivou značajnosti od p lt 0.05, hi-kvadrat testom i Kaplan-Majerovom analizom (dužina servis perioda). Rezultati prvog ultrazvučnog pregleda su ukazali da nema statistički značajnih razlika u morfologiji jajnika i dominantnog folikula između suplementiranih grupa u odnosu na kontrolnu grupu krava. Rezultati drugog ultrazvučnog pregleda su ukazali da postoji statistički značajna razlika između srednjih vrednosti prečnika dominantnog folikula na levom jajniku kod kontrolne grupe krava u odnosu na suplementirane životinje (1,67±0,53:1,12±0,29 i 1,11±0,35 cm, p lt 0.05, O3:O1 i O2). Zbirne vrednosti procenta koncepcije nakon prvog i drugog osemenjavanja bile su statistički značajno više kod suplementiranih krava u odnosu na kontrolnu grupu životinja (60% : 81% : 25%; O1:O2:O3, p lt 0,05, hi-kvadrat test). Najniža vrednost indeksa osemenjavanja je utvrđena kod ogledne grupe krava suplentirane Ketal-om (1.69±0.79), koja je bila značajno viša u odnosu na kontrolnu grupu krava (3.38±1.36, p lt 0,05). Dužina servis perioda je bila najmanja kod grupe krava suplementiranih Ketal-om (100±35 days) i značajno se razlikovala u odnosu na ostale ogledne grupe (168±59 i 157±52 dana, O1 i O2), što je potvrđeno Kaplan Majerovom analizom. Energetska suplementacija mlečnih krava propilen glikolom tokom peripartalnog perioda može dovesti do povećanja procenta gravidnih krava nakon prvog i drugog osemenjavanja, smanjenja vrednosti indeksa osemenjavanja i skraćenja dužine servis perioda

The trends in maize and wheat production in the Republic of Serbia

The total area under cereals during 2018 remained at a long-term stable level of about 1.7 million hectares. Maize and wheat are the most important crops grown in the Republic of Serbia. In the structure of harvested areas under cereals, maize dominates (53%), followed by wheat (38%). The objective of this paper was to determine if there was a recognisable trend line for the production of these crops in the 2007-2018 period. The yield data (Area harvested (ha), Production (tonnes), Production (t/ha)) were collected from the Statistical Office of the Republic of Serbia. Calculations of relevant and valid trends using central tendency measures, dispersion measures, relative ratios and percentage growth were used for statistical data processing. During the observation period, the average annual growth in maize yield was 6.38%, while the average annual growth in wheat yield was slightly lower, 2.00%. However, it is not possible to create an appropriate trend line for any of the variables in order to predict a future time period, since the coefficient of determination is low.Ukupna poljoprivredna površina pod strnim žitima u 2018. godini nije puno varirala u odnosu na prethodne godine i iznosila je oko 1.7 miliona hektara. Kukuruz i pšenica predstavljaju najznačajnije biljne kulture koje se gaje u Republici Srbiji. U strukturi požnjevenih površina pod žitaricama kukuruz je dominirao sa čak 53% i bio je praćen od strane pšenice sa 38%. Cilj ovog rada bio je utvrditi postoji li prepoznatljiva linija trenda proizvodnje ovih kultura za period od 2007. do 2018. godine. Podaci o prinosu (požnjevena površina (ha), proizvodnja (u tonama), prinos (t/ha)) prikupljeni su od Republičkog zavoda za statistiku. Za statističku obradu podataka korišćeni su proračuni relevantnih i validnih kretanja primenom mera centralne tendencije, mera disperzije, relativnih pokazatelja i procentualnog rasta. Prosečni godišnji rast prinosa kukuruza u posmatranom periodu iznosi 6,38%, dok je za pšenicu prosečan godišnji rast u posmatranom periodu nešto manji i iznosi 2,00%. Međutim, ni za jednu od promenljivih nije moguće napraviti odgovarajuću liniju trenda, u cilju predviđanja za budući vremenski period, jer je koeficijent determinacije mali