Molecular genetic identification of Lotmaria passim Schwarz, 2014 trypanosome and the analysis of its impact on the health of bee colonies and economic effects in apiculture.

Zbog nepostojanja molekularne metode za determinaciju vrsta pčelinjih tripanozoma Crithidia mellificae i Lotmaria passim bez naknadnog sekvencioniranja, definisan je cilј ovog rada, a to je molekularna identifikacija tripanozome L. passim i ispitivanje njenog uticaja na zdravlјe pčelinjih zajednica i ekonomske efekte u pčelastvu. Razvijeni su specijes-specifični prajmeri za PCR detekciju C. mellificae i L. passim kao i real-time PCR metoda za detekciju i kvantifikaciju L. passim. Uzorci pčela koji su sakupljani u Srbiji u devetogodišnjem periodu (2007-2015) retrospektivno su analizirani kako bi se utvrdila prevalencija ovog eukariotskog parazita molekulanrnom analizom DNA. Kako bi se utvrdila godišnja dinamika L. passim, njen uticaj na oksidativni stres, kao i na ekonomsku dobit formirane su dve grupe košnica. Istraživanje je sprovedeno na ukupno dvadeset Langstroth košnica, 10 košnica koje su bile L. passim-pozitivne i 10 košnica koje su bile L. passim-negativne, a koje su se nalazile na dva različita pčelinjaka. Tokom trajanja eksperimenta (od marta 2016. do marta 2017. godine) svakog meseca izuzev zimskih meseci (oktobar-februar) iz svake košnice je uzorkovano najmanje 120 živih odraslih pčela sa leta košnice (za detekciju i kvantifikaciju L. passim i Nosema spp), a u junu i septembru 20 živih odraslih pčela za potrebe analize parametara oksidativnog stresa. Razvijeni su specijes-specifični prajmeri za PCR detekciju tripanozoma vrste C. mellificae i L. passim, koji su validirani i u uslovima mešovite infekcije, kao i infekcije tripanozomom bumbara Crithidia bombi. Infekcija sa N. apis i N. ceranaesu analizirane korišćenjem PCR. Tehnikom real-time PCR je utvrđen nivo infekcije vrstom L. passim kod L. passim-pozitivnih društva, dok je brojanjem spora određen nivo infekcije sa N. ceranae u svim društvima. Analizirani su uzorci pčela iz 162 društva (18 iz svake godine), koji su prikupljeni sa 57 različitih lokacija. L. passim je detektovana u uzorcima koji su poticali iz svake godine i kod prosečno 62,3% (godišnja prevalencija od 38,9% do 83,3%)...Due to the absence of molecular methods intended for species-specific identification of bee trypanosomes Crithidia mellificae and Lotmaria passim without further sequencing, the goal of this thesis has been defined: molecular identification of L. passim trypanosome and the research into its impact on the colony health and economic effects in apiculture. Species-specific primers for PCR detection of C. mellificae and L. passim as well as a real-time PCR method for the detection and quantification of L. passim were developed. Archival bee samples collected in Serbia during a nine-year period (2007-2015) were analysed retrospectively to assess the prevalence of this eukaryotic parasite by molecular DNA analysis. To determine the annual dynamic of L. passim infection, and its influence on oxidative stress and the economic income two apiaries were chosen. Ten hives from each made up the two experimental groups, the L. passim-positive from the one and the L. passim-negative from another. During the experimental period (from March 2016 to March 2017) each month with the exception of winter months (October-February) from every hive 120 live adult bees were collected from the hive entrance for the detection and quantification of L. passim and Nosema spp. In addition, in June and September 20 live adult bees were collected in the same manner for oxidative stress analysis. Species-specific primers for PCR detection of the two trypanosomatids, C. mellificae and L. passim, were developed and validated for target specificity under single and mixed-species conditions as well as against the bumblebee trypanosomatid Crithidia bombi. Infections with N. apis and N. ceranae were analysed using the PCR assay. Infection levels with L. passim in L. passim-positive colonies were detected with the real-time PCR, and the N. ceranae infection level by spore counting in all of the colonies. A total of 162 colonies (18 originating from each year), collected from 57 locations were analysed. L. passim was detected in samples provided each year in 62.3% of samples (ranging between 38.9% and 83.3%)..

Molekularno-genetička identifikacija tripanozome Lotmaria passim Schwarz, 2014 i analiza njenih efekata na zdravlje pčelinjih zajednica i ekonomske efekte u pčelarstvu

Due to the absence of molecular methods intended for species-specific identification of bee trypanosomes Crithidia mellificae and Lotmaria passim without further sequencing, the goal of this thesis has been defined: molecular identification of L. passim trypanosome and the research into its impact on the colony health and economic effects in apiculture. Species-specific primers for PCR detection of C. mellificae and L. passim as well as a real-time PCR method for the detection and quantification of L. passim were developed. Archival bee samples collected in Serbia during a nine-year period (2007-2015) were analysed retrospectively to assess the prevalence of this eukaryotic parasite by molecular DNA analysis. To determine the annual dynamic of L. passim infection, and its influence on oxidative stress and the economic income two apiaries were chosen. Ten hives from each made up the two experimental groups, the L. passim-positive from the one and the L. passim-negative from another. During the experimental period (from March 2016 to March 2017) each month with the exception of winter months (October-February) from every hive 120 live adult bees were collected from the hive entrance for the detection and quantification of L. passim and Nosema spp. In addition, in June and September 20 live adult bees were collected in the same manner for oxidative stress analysis. Species-specific primers for PCR detection of the two trypanosomatids, C. mellificae and L. passim, were developed and validated for target specificity under single and mixed-species conditions as well as against the bumblebee trypanosomatid Crithidia bombi. Infections with N. apis and N. ceranae were analysed using the PCR assay. Infection levels with L. passim in L. passim-positive colonies were detected with the real-time PCR, and the N. ceranae infection level by spore counting in all of the colonies. A total of 162 colonies (18 originating from each year), collected from 57 locations were analysed. L. passim was detected in samples provided each year in 62.3% of samples (ranging between 38.9% and 83.3%)...Zbog nepostojanja molekularne metode za determinaciju vrsta pčelinjih tripanozoma Crithidia mellificae i Lotmaria passim bez naknadnog sekvencioniranja, definisan je cilј ovog rada, a to je molekularna identifikacija tripanozome L. passim i ispitivanje njenog uticaja na zdravlјe pčelinjih zajednica i ekonomske efekte u pčelastvu. Razvijeni su specijes-specifični prajmeri za PCR detekciju C. mellificae i L. passim kao i real-time PCR metoda za detekciju i kvantifikaciju L. passim. Uzorci pčela koji su sakupljani u Srbiji u devetogodišnjem periodu (2007-2015) retrospektivno su analizirani kako bi se utvrdila prevalencija ovog eukariotskog parazita molekulanrnom analizom DNA. Kako bi se utvrdila godišnja dinamika L. passim, njen uticaj na oksidativni stres, kao i na ekonomsku dobit formirane su dve grupe košnica. Istraživanje je sprovedeno na ukupno dvadeset Langstroth košnica, 10 košnica koje su bile L. passim-pozitivne i 10 košnica koje su bile L. passim-negativne, a koje su se nalazile na dva različita pčelinjaka. Tokom trajanja eksperimenta (od marta 2016. do marta 2017. godine) svakog meseca izuzev zimskih meseci (oktobar-februar) iz svake košnice je uzorkovano najmanje 120 živih odraslih pčela sa leta košnice (za detekciju i kvantifikaciju L. passim i Nosema spp), a u junu i septembru 20 živih odraslih pčela za potrebe analize parametara oksidativnog stresa. Razvijeni su specijes-specifični prajmeri za PCR detekciju tripanozoma vrste C. mellificae i L. passim, koji su validirani i u uslovima mešovite infekcije, kao i infekcije tripanozomom bumbara Crithidia bombi. Infekcija sa N. apis i N. ceranaesu analizirane korišćenjem PCR. Tehnikom real-time PCR je utvrđen nivo infekcije vrstom L. passim kod L. passim-pozitivnih društva, dok je brojanjem spora određen nivo infekcije sa N. ceranae u svim društvima. Analizirani su uzorci pčela iz 162 društva (18 iz svake godine), koji su prikupljeni sa 57 različitih lokacija. L. passim je detektovana u uzorcima koji su poticali iz svake godine i kod prosečno 62,3% (godišnja prevalencija od 38,9% do 83,3%)..

Nutritivni kvalitet hraniva koja se koriste u ishrani mlečnih koza u Vojvodini

The study was to conduct to evaluate the chemical composition and nutritive values of feedstuffs (forages and concentrate mixtures) used for dairy goats nutrition in Vojvodina. Samples were collected from six farms, including one organic farm. The results showed that the relative feed values of analyzed forages were in the range of good, medium to lower quality. Average protein content from lowest to highest for investigated forages was: corn silage (Zea Mays) (65.37-82.57g kgˉ¹DM), alfalfa haylage (Medicago sativa L.) (159.99-184.17g kgˉ¹DM), pasture (185.30g kgˉ¹ DM), and alfalfa hay (Medicago sativa L.) (167.48-203.60g kgˉ¹DM). The non-fibre carbohydrates and protein content most varied in organic hay samples (cv: 29.25% and 19.09%, respectively). Generally, feedstuffs used in organic nutrition, including organic concentrate, were of lower nutritional quality and moreover contained higher amounts of crude fibre and lignin. Especially, a high source of variation was observed in investigated concentrate mixtures for the crude protein content (p lt 0.0001), ranged from 135.32 to 209.87g kgˉ¹DM. Corn silages also varied substantially in their chemical composition and significant difference (p lt 0.05) was observed in regard to acid detergent fibre (ADF) and lignin content (ranged: ADF: 242.20-319.24g kg‾¹DM; ADL: 27.98-52.54g kg‾¹DM, respectively). Furthermore, pasture contained the most soluble materials during May and June and their content was related inversely to crude fibre amount. This survey highlights that investigated farms still pay insufficient attention to the quality of the feedstuff. For the development of intensive goat farming, greater emphasis should be placed on using higher quality feedstuffs, as well, standards for feed quality must be considered and established.Istraživanje je bilo sprovedeno sa ciljem procene hemijskog sastava i nutritivne vrednosti kabastih hraniva i smeša koncentrata koja se koriste u ishrani mlečnih koza u Vojvodini. Ispitivano je ukupno šest farmi,uključujući i organsku farmu. Dobijeni rezultati su pokazali da se relativna hranibena vrednost analiziranih kabastih hraniva kretala od dobrog, srednjeg do slabijeg kvaliteta. Prosečan sadržaj proteina od najmanjih do najviših vrednosti se kretao u opsegu: kukuruzna silaža (Zea Mays) (65.37-82.50g kg‾¹DM), senaža lucerke (Medigao sativa L.) (159.99-184.17g kg‾¹DM), pašnjak (185.30g kg‾¹DM ) i seno lucerke (Medigao sativa L.) (167.48-203.60g kg‾¹DM). Sadržaj nestrukturnih ugljenih hidrata i proteina pokazao je najveće varijacije u uzorcima organskog sena (cv: 29.25% и 19.09%, pojedinačno). Generalno, hraniva koja su bila ispitivana na organskoj farmi, uključujući organske smeše koncentrata, su pokazale lošiji nutritivni kvalitet usled većeg sadržaja sirovih vlakana i lignina. Posebno su utvrdjene velike varijacije u ispitivanim smešama koncentrata u pogledu sadržaja proteina (p lt 0.0001), koji je bio rangiran od 135.32 do 209.87g kg‾¹DM. Kukuruzne silaže su takodje značajno varirale u njihovom hemijskom sastavu i signifikantna razlika (p lt 0.05) je utvrdjena u pogledu sadržaja kiselih deteržent vlakana (ADF) i lignina (u opsegu: ADF: 242.20-319.24g kg‾¹DM; ADL: 27.98-52.54g kg‾¹DM, pojedinačno). Osim toga, utvrdjeno je da je pašnjak posedovao najviše rastvorljivih materija tokom Maja i Juna meseca a njihov sadržaj je bio obrnuto povezan sa sadržajem sirovih vlakana. Ovo istraživanje je pokazalo da ispitivane farme još uvek ne posvećuju dovoljno pažnje kvalitetu hraniva. Za razvoj intenzivnog uzgoja koza, veći naglasak treba staviti na upotrebu kvalitetnijih hraniva i istovremeno standardi kvaliteta hrane moraju biti razmotreni i utvrđeni

The quality of goat milk and hygiene management practices on farms in Vojvodina

The present work aimed to study the goat farms concerning different hygiene-sanitary and health management practice. Also, bulk tank milk of Alpine breed goats was used to investigate changes in the composition of milk during lactation on six farms in Vojvodina Region. The results showed that although 96.67% of farmers were familiar with mastitis, approximately 56.67% of farmers reported a lack of knowledge about subclinical mastitis and therefore not intensely monitoring udder health during the lactation period. Somatic cell count (SCC) and total bacteria count (TBC) were the most variable traits in our research and lactation average SCC between investigated farms showed a significant difference (P < 0.01) (a range from 1088×10³/ml to 3129×10³/ml). At the same time, TBC was found in a wider range, from 66×10³/ml to 3508×10³/ml. Further-more, SCC and TBC often did not meet the recommended quality level. Therefore, during the entire lactation period, 63% of the milk samples contained above 1.5 million SCC/ml and 37% of the samples were contained TBC above 1.5 million CFU/ ml. Results also confirmed considerable seasonal variations of goat milk composition and the milk fat was the component that most varied (cv: 33.16%). It was observed that organic in comparison to conventional milk chemical composition, was signifi-cantly different, especially in terms of protein content (P < 0.0001). In conclusion, goat dairy production could be of considerable importance in Vojvodina but dairy goat sector requires a more systemic approach, better hygiene milking conditions and implemented prevention and control programmes during the milking routine

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

Uzgoj svinja i proizvodnja svinjskog mesa u Republici Srbiji početkom 2022 – izazovi i prilike

Na osnovu Ankete o poljoprivrednoj proizvodnji koju sprovodi Republički zavod za statistiku, broj svinja u Republici Srbiji krajem 2021. manji je za 3,9% u odnosu na broj svinja u 2020. što je u odnosu na desetogodišnji prosek (2011–2020) smanjenje od 6,5%. Procenjuje se da je proizvodnja svinjskog mesa u Republici Srbiji u prvom kvartalu 2022. manja za oko 48,2% u odnosu na poslednji kvartal 2021.godine. Uzgoj svinja smatra se tradicionalnom proizvodnjom pretežno ruralnog stanovništva, sa elementima socijalnog i kulturološkog karaktera. Sa ciljem očuvanja i uspostavljanja održivog razvoja iste, često se inicira odgovorniji pristup i strateško uređenje oblasti svinjarstva. Za razliku od situacije u Republici Srbiji, očuvanje populacije svinja je i u 2022. godini u centru pažnje u EU. Statistički posmatrano, u 2021. došlo je do pada ukupnog broja svinja (EU 27) za oko 2,9% u odnosu na predhodnu godinu, dok desetogodišnji prosek (2012-2021) beleži neznatno smanjenje od oko 0,1%. Suočeni sa padom cena svinjskog mesa i visokim troškovima i dalje održive proizvodnje, novonastala, i za mnoge članice EU izazovna situacija u sektoru, rezultat je zaliha prethodnih godina (2020-2021), kao i ograničenom potražnjom koju prati smanjenje izvoznih mogućnosti (za Kinu). Na međunarodno tržište svinjskog mesa uticaj ima i brzi tehnološki napredak u poslednjoj deceniji, koji pruža odgovore, posebno kada su u pitanju priplodna grla, sa podacima kvantitativnih genetskih analiza relevantnih za ekonomsku isplativost i profitabilnost uzgoja svinja. Dalje, cene hrane, uopšte, na globalnom nivou nastavljaju sa rastom, dok se posebna pažnja posvećuje zahtevima potrošača, baziranim na odluci za hranu, koju prate informacije zasnovane na dokazima. Istraživanja, organizovana u EU pokazuju da potrošači sve više žele meso iz boljih uslova uzgoja, te je značajno učiniti vidlјivim stvarne uslove uzgoja svinja u štalama, uključujući i stepen zaštite životne sredine na mestu uzgoja. Posebni značaj posvećuje se i zaštiti zdravlјa životinja (uključuje i borbu protiv rastućeg problema antimikrobne rezistencije), koja je trenutno na čelu tehnološke i digitalne transformacije ka održivom polјoprivredno-prehrambenom sektoru sa ispunjenim uslovima o dobrobiti životinja. Do sada suprotstavljeni interesi, ukoliko postoje preklapanja – prilika su za promene u pozitivnom smeru. U radu želimo istaći izazove sa kojima će se suočiti domaći farmeri koji se bave uzgojom svinja, stručna javnost i domaći potrošači.Zbornik radov

Distribucija pojave trihineloze svinja i ljudi na teritoriji Republike Srbije u periodu od 1994. do 2018. godine

Introduction. Trichinellosis is a disease in humans caused by parasites of the genus Trichinella, and these roundworms can occur in a variety of animals (over one hundred mammal species). Members of the genus Trichinella are present in almost all continents and in all climate zones. Intensive studies on the eradication of this disease have been going on for a long period, but despite the finances invested in research projects, trichinellosis is still present in the 21st century and poses a major health issue all over the world. According to current scientific estimations, there are over 27 million Trichinellainfected people in the world. The aim of our study was to determine the distribution and trends for Trichinella infection in pigs and trichinellosis in humans in Serbia between 1994 and 2018. Materials and Methods. Data for the 25-year surveillance period of Trichinella cases registered in pigs and humans in Serbia was gathered from the Veterinary Directorate and from the Institute of Public Health of the Republic of Serbia. The data obtained was analysed with the relative numbers of structure and dynamics, indices and descriptive statistical indicators. Results and Conclusions. During the research period, 14,837 pigs were diagnosed as infected with Trichinella. Out of this number, 87.31% of pigs were identified in the five epizootiological regions, and only 12.69% were diagnosed in the non-epizootiological regions in Serbia. During the period 1994-2018 in Serbia, a total of 6,850 people were treated for Trichinella infection. Out of this number, 4,153 (60.63%) people were from the five epizootiological regions. The trend-line describing the presence of Trichinella in pigs was defined by a fourth degree polynomial function. Meanwhile, the trendline describing the presence of trichinellosis in humans was defined by a sixth degree polynomial function. Trichinellosis in Serbia is most common during the winter season, from December to March.Uvod. Trihineloza je zajednička bolest životinja i ljudi (više od sto vrsta sisara) uzrokovana parazitima koji pripadaju rodu Trichinella. Pripadnici ovog roda nađeni su na gotovo svim kontinentima i u svim klimatskim oblastima. Dugi niz godina traju intenzivna istraživanja na suzbijanju ove parazitoze, ali i pored velikog broja istraživanja i velikih novčanih sredstava uloženih u projekte za kontrolu i eradikaciju trihineloze, ona i u 21. veku predstavlja ozbiljan zdravstveni problem gotovo u celom svetu. Na osnovu procena nekih naučnika danas je u svetu parazitom Trichinella spp. zaraženo oko 27 miliona ljudi. Cilj našeg istraživanja bio je da se u periodu od 1994. do 2018. godine, ustanovi distribucija pojave treihineloze kod svinja i kod ljudi na teritoriji Republike Srbije, kao i da se uradi analiza trenda pojave ove bolesti kod ljudi i životinja. Materijal i metode. Podaci prijavljenih slučajeva trihineloze u populaciji svinja i ljudi tokom dvadesetpetogodisnjeg perioda preuzeti su iz Uprave za veterinu i Instituta za javno zdravlje Republike Srbije. Podaci su analizirani primenom relativnih brojeva struktura i dinamike, procentima kao i opisnim statističkim parametrima. Rezultati i zaključak. Za vreme trajanja istraživanja na teritoriji Republike Srbije dijagnostikovano je ukupno 14.837 obolelih svinja, od tog broja na analiziranim epizootiološkim područjima dijagnostikovano je 87,31% obolelih svinja, a na ostaloj teritoriji Srbije samo 12,69%. Za ceo ispitivani period obolelo je ukupno 6.850 građana Srbije. Od tog broja 4.153 građana je obolelo na teritoriji analiziranih epizootioloških područja, što predstavlja 60,63% od svih obolelih građana na teritoriji Srbije. Najbolje prilagođena linija trenda pojave trihineloze kod svinja je polinom četvrtog stepena, dok je najbolje prilagođena linija pojave trihineloze kod ljudi polinom šestog stepena. Trihineloza se kod ljudi najčešće javlja u periodu od decembra do marta

Retrospective analysis of the bluetongue outbreak in Serbia

Bluetongue, a vector-born disease caused by the Bluetongue virus (BTV) and transmitted by Culicoides biting midges, is considered to be one of the most important diseases of domestic ruminants. The first outbreak of bluetongue in Serbia was reported in 2001, when BTV serotype 9 was identified in sampled materials. In 2014, outbreak of BTV-4 in Serbia caused considerable economic losses affecting sheep, cattle and goats. During this outbreak, BTV-4 was recorded in 644 outbreaks within 49 municipalities, part of 17 administrative regions. From the total number of sheep kept in areas affected by bluetongue (n=1 748 110), 2 083 cases (0.2%) were proven to be BTV-4 infected. Total of 206 infected cattle and 24 infected goats were reported during this investigation period, which represents 0.06% and 0.03% of the total number of cattle and goats kept in affected areas, respectively. The highest incidence of infected sheep, cattle and goats was recorded on the territory covered by veterinary institute of Nis. Recorded lethality in cattle, sheep and goats was 18.45% (n=38), 48.10% (n=1002) and 54.17% (n=13), respectively. The peak of the outbreak was in September and October when 94.43% of the confirmed positive cases, regardless of the species, was recorded. Monitoring of bluetongue disease in Serbia relies on active surveillance programmes aimed at: (i) identification and tracing of susceptible and potentially infected animals and (ii) detection, distribution and prevalence of insect vectors. Vaccination of sheep is planned to be implemented as a control measure against bluetongue in Serbia

Looking for the causes of and solutions to the issue of honey bee colony losses

Colony losses, including those induced by the colony collapse disorder, are an urgent problem of contemporary apiculture which has been capturing the attention of both apiculturists and the research community. CCD is characterized by the absence of adult dead bees in the hive in which few workers and a queen remain, the ratio between the brood quantity and the number of workers is heavily disturbed in favor of the former, and more than enough food is present. Robbing behavior and pests usually attacking the weakened colony do not occur. In the present paper, the causes of the emergence of this problem are discussed, as well as the measures of its prevention. The following factors, which lead to colony losses, are analyzed: shortage of high-quality food (pollen and honey); infestation with parasites, primarily with Varroa destructor, and mixed virus infections; bacterial infections (American and European foulbrood), fungal infections (nosemosis and ascosphaerosis) and trypanosomal infections (lotmariosis); and, finally, general management of the apiary. Certain preventive measures are proposed: (1) providing ample high-quality forage and clean water, (2) avoiding sugarisation, i.e. superfluous use of sugar syrup, (3) meeting the nutritional needs of the colony, (4) when feeding bees, taking care of the timing and the composition of diet, avoiding pure sugar syrup which in excessive quantities may induce energetic and oxidative stress, (5) when there is a shortage of natural feed - honey in the brood chamber - use sugar syrup with natural/artificial supplements to avoid protein starvation, (6) organized control of V. destructor in the colonies is obligatory due to its vector role, and (7) compliance with hygienic and sanitary measures and principles of good apiculture practice and management in apiaries. To conclude, all preventive measures are feasible in compliance with rules and regulations concerning regular spring and autumn bee health monitoring by licensed veterinarians, who can propose adequate treatments if necessary

Oxidative Stress, Endoparasite Prevalence and Social Immunity in Bee Colonies Kept Traditionally vs. Those Kept for Commercial Purposes

Commercially and traditionally managed bees were compared for oxidative stress (superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST) and malondialdehyde (MDA)), the prevalence of parasites (Lotmaria passim, Crithidia mellificae and Nosema ceranae/apis) and social immunity (glucose oxidase gene expression). The research was conducted on Pester plateau (Serbia—the Balkan Peninsula), on seemingly healthy colonies. Significant differences in CAT, GST and SOD activities (p p L. passim and N. ceranae was significantly (p p L. passim was detected in honey bee brood. In commercial colonies, the prevalence of L. passim was significantly (p p < 0.01) higher, which probably results from their increased need to strengthen their social immunity. Commercially kept colonies were under higher oxidative stress, had higher parasite burdens and higher GOX gene transcript levels. It may be assumed that anthropogenic influence contributed to these differences, but further investigations are necessary to confirm that