Milorad Mirilovic

Endocrine and metabolic profile in Holstein and red Holstein heifers during peripartal period

The aim of this stady was to examine the relationship between triiodothyronine (T3), thyroxin (T4), insulin-like growth factor-I (IGF-I) and blood serum liver function biomarkers concentrations in Holstein and Red Holstein heifers during the peripartal period. In the first experimental group (I) were heifers of Holstein Friesian breed (n=10), and in the second experimental group (II) were Red Holstein heifers (n=10). Blood samples were taken from the vena coccygea three times during the short peripartal period (5 days before delivery, at delivery and 5 days after delivery), and blood serum samples were separated after spontaneous coagulation. Blood serum T3, T4 and IGF-I concentrations were determinated using radioimmunoassay (RIA). Blood serum concentrations of glucose (G), total protein (TP), albumin, (Alb), urea, total bilirubin (tBil) and aspartate aminotrasferase (AST) were determined using commercial ELISA kits. The statistical significance between means was determined using Student t-test. Blood serum T3 concentration in Group II was significantly lower after delivery, and T4 concentration was significantly higher before delivery (p<0.05), compared to Group I. Mean blood serum IGF-I concentrations between the two experimental groups were not significantly different at all time intervals. Relationships between the determined hormones showed a median positive correlation between T3, and T4 (r=0.74) in Group I and highly positive correlation in Group II (r=0.81). Blood serum thyroid gland hormones and IGF-I concentrations in healthy heifers during peripartal period vary considerably, the lowest values being determined immediately after calving in both experimental groups. Blood serum G, TP, Alb and urea concentrations were significantly higher in Group I at all investigated time intervals. Blood serum tBil concentration was significantly higher after partus in Group I (11.02 ± 3.33 : 8.49 ± 3.35 μmol/L, Group I vs. II, respectively), and AST activity was not significantly different at all intervals.

MRSA in pigs in Serbia

Meticilin-resistant Staphylococcus aureus (MRSA) primarily causes human infections; however, over the past several years pigs have been identified as a source of human MRSA infection in Europe ([EFSA 2009][1]). We undertook a study to sample pigs in Serbia for the presence of MRSA. A mid-scale,

Efficiency evaluation of a bivalent vaccine in the prophylaxis of mastitis in cows.

Mastitis in cows represents one of the most actual problems in intensive dairy production. The longtime different approaches to the treatment of mastitis have not offered a suitable solution, and the problem of mastitis is still present and acute. Prevention of pathogen penetration into the mammary gland, its colonization and multiplication impose a constant need for regular inspections of milk, as well as preventive and therapeutic measures to reduce the incidence of mastitis. Studies in the field of vaccination of ruminants against mastitis pathogens suggest a limited success in obtaining significant results in immunoprophylaxis. Considering the results of other researchers and our own research, and bearing in mind the problems mastitis caused by Staphylococcus aureus and Streptococcus agalactiae represent, the aim of this study was the preparation and testing of an indigenous vaccine prepared with two stable strains, SAU 7 (S. aureus) and SAG 3 (Str.agalactiae). The dose was 5 mL/cow and consisted of inactivated bacterial S. aureus SAU 7 cells in a concentration of 1x1010 cfu/mL and Str. agalactiae SAG 3 in a concentration of 4 x 109 cfu/mL. The number of somatic cells in the milk samples during the whole study period was higher in vaccinated cows in both groups compared with the control, but this difference was not statistically significant. The concentration of immunoglobulin IgG in the milk of vaccinated cows was significantly higher than the concentration of this class of proteins in the milk of unvaccinated cows. [Projekat Ministarstva nauke Republike Srbije, br. III 46002]

The influence of pulverised sugar dusting on the degree of infestation of honey bee colonies with Varroa destructor.

The aim of this work was the investigation on the efficacy of pulverised sugar dusting on knocking-down Varroa destructor mites and the influence of the dynamics of the treatment on the degree of infestation in honey bee colonies. Two methods were deployed to measure the degree of infestation of bee colonies with V. destructor mites: the sugar shake method and the technique which involves mesh bottom boards equipped with sticky inserts. The research was carried out on 30 strong honey bee colonies in three successive years. The results proved that dusting with pulverised sugar (particle diameter below 40 μm) influenced the fall of V. destructor in comparison with both their fall off prior to the treatment and the negative control. The most discernible effects on the mite fall and the decline in their population in the hives was obtained with dustings repeated at threeday intervals. To conclude, the dynamics of the treatment affected the degree of infestation in bee colonies. However, the efficacy of sugar dusting was significantly lower in comparison with the one of flumethrin (positive control). Thus, in spite of considerable favourable effects on the decline in the degree of infestation with mites, by no means may dusting with pulverised sugar be advised to beekeepers as the one and only means of bee protection against V. destructor. The use of the technique which involves mesh bottom boards equipped with sticky inserts proved more efficacious and sensitive in the judgment of the degree of infestation of bee colonies in comparison with the sugar shake method, which includes dusting 300 bees with 40 g of pulverised sugar (particle diameter below 40 μm).

Retrospective Analysis of the Bluetongue Outbreak in Serbia

Abstract 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.

Quantitative PCR assessment of Lotmaria passim in Apis mellifera colonies co-infected naturally with Nosema ceranae

A recently described trypanosomatid species Lotmaria passim and the microsporidium Nosema ceranae infect the honey bee (Apis mellifera), but the interspecific dynamic of these two common gut parasites is unknown. In this study, a real-time qPCR assay was developed to enable the specific detection and quantification of L. passim. The annual dynamics of N. ceranae and L. passim infections were evaluated in ten A. mellifera colonies naturally infected with both parasites at one apiary in Serbia from March 2016 to March 2017. Ten samples (60 bees abdomens) were taken from each colony on 8 sampling occasions. L. passim infection level was evaluated with qPCR, while N. ceranae infection was measured by spore counts. N. ceranae infection level was significantly higher in comparison with that of L. passim (spore or cell equivalents/bee, respectively). Significant positive correlation between infection levels of the parasite species indicates their similar annual dynamics, whilst the differences in the levels of infection between particular months point to a seasonal pattern in the incidence of both parasites. The assay which has been developed and validated creates opportunity for detailed study of L. passim infection kinetics and the improvement in the management practices in beekeeping related to these two parasites.

Placental Iodothyronine Deiodinases Expression in Pregnant Cows Exposed to Propylthiouracil (Ptu) and Thyroid Axis Activity of their Calves

Abstract The aim of our study was to investigate if the thyroid axis of newborn calves is affected by prenatal application of propylthyouracil (PTU). The study included 20 late pregnant Holstein cows. One group (n=10) was treated with PTU (4 mg/kg of BW daily) from day 20 before expected calving until the day of calving. The other group (n=10) was non-treated. Placental samples of dams were obtained for measuring mRNA expression of iodothyronine deiodinases type I (D1), type II (D2) and type III (D3). After parturition calves were separated from the dams and included in the study. Blood samples were taken daily from each calf starting on the day of birth until day 7 of age. Blood T3, T4 and TSH concentrations were measured. PCR analysis of the placental tissue revealed an abundance of all three types of placental deiodinases in non-treated cows, and a significant elevation of mRNA levels for all three types of deiodinases after PTU treatment. Calves that originated from dams treated with PTU had significantly lower T3 and T4 and significantly higher TSH concentrations compared to non-treated calves during the first 2 days of life. Starting from day 4 until day 6 of life the opposite effect was observed meaning that calves prenatally exposed to PTU had significantly higher T3 and T4 and slightly lower TSH. Our study, for the first time, provides information related to iodothyronine deiodinases mRNA expression in bovine placenta, and confirm that PTU treatment of pregnant dams provokes depression of thyroid function in newborns during the first days of life.

Management and control program for suppression and eradication of classical swine fever in Serbia

Classical swine fever (CSF) has been present in Serbia for a long period of time as an endemic disease, and it occurs with lesser or greater intensity from year to year. Since it is a highly contagious disease of domestic and wild pigs, the outbreaks of the disease causes severe consequences for animal welfare, livestock production and economic losses to the national economies in countries where it occurs. Therefore, CSF has a great epizootiological and economic importance to the swine production, primarily because of trade restrictions for live pigs and pork products. CSF eradication and control programmes are generally based on vaccination strategies in countries with endemic occurrence of CSF or non-vaccination policies in contries wich successfully eradicated or are free of CSF. Whatever the general eradication stategy is in place, in the case of an outbreak of CSF the stamping-out method is used for suppression and eradication of the disease, with strict implementation of specific veterinary-sanitary measures in the infected and surveillance zones, clearly defined by legal provisions. In the period before 2006, there were certain regions in Serbia where CSF occurred almost every year, including regions where pig farming was not the primary branch of animal husbandry. Pig identification and implementation of vaccination, as well as the control of trade of pigs from infected areas to other parts of the country were not very successful. Due to the serious losses inflicted by the disease, a new Programme of CSF control was adopted in 2006, which inter alia included the obligatory identification of pigs, registration of pig holdings and free of charge vaccination of all susceptible animals in the country, as well as the implementation of other statutory measures, including obligatory evidence of veterinary activities in the national Veterinary information system. The results obtained in the period after the implementation of the Programme of CSF control (2007, 2008 and 2009) indicate a positive impact on the reduction of outbreaks of CSF, as well as on the reduction of prevalence (p<0.001). Also, the effectiveness of vaccination of pigs in 2007 compared to the period before and after the implementation of the Programme was the highest (97.78%), as well as the costs of its implementation.

Effects of the application of trichinellosis control program in an endemic area in Serbia

Trichinellosis is a disease that affects both humans and animals, caused by a parasite from the Trichinellidae family and Trichinella genus. Humans get infected by consuming infected and inadequately thermally treated meat from domestic or wild animals containing cocooned infective larvae of T. spiralis. Aside from health problems caused by trichinellosis as a zoonosis, there is no doubt that it represents a serious economic problem for swine meat producers. The research in this paper has been performed in Serbia, in a region which is located at the confluence of two large rivers, and it is the geographical location which makes it an endemic area for the presence of T. spiralis. Epidemiological data pertains to the period of 1995-2003, but also to the period 2003-2009, when the implementation of the program for control and eradication of trichinellosis was complete. The diagnostic testing of cadavers of slaughtered swine for the presence of T. spiralis in the period of 1995-2003 included 41.04% of the slaughtered swine, out of which 0.4281% were positive, and the amount of economic loss was 95301000 dinars or about one million EUR. The infection was confirmed in 432 patients during the research period. The preparation of the program for the control and eradication of trichinellosis has been made in accordance with applicable laws and technological standards, with a clear determination of input and output using a cost-benefit analysis. The effects of its application show a reduction in the number of swine which are positive for the presence of T. spiralis by a factor of three times (p<0.01), and the present net value (PNV) and the benefit/cost ratio (B/C) show economic and epidemiological justification.

Simulation of the Transmission by Vectors of Bluetongue Disease and Analysis of the Control Strategy

Abstract Bluetongue disease is an infectious non-contagious disease of domestic and wild ruminants, transmitted by hematophagous insects of the genus Culicoides. In endemic areas the disease has a seasonal character, occurs usually in summer when the population of vectors is at its peak. Culicoides are active at temperatures in the range from 13oto 35oC. The replication of the virus stops when the environmental temperature is below 13oC. It has been reported that the temperature and humidity of the environment affect to a great extent the biology of the vector and the survival of the virus in the reservoirs. During the summer, the number of infected cattle and sheep is directly dependent on the density of the population of the vector, the length of vectors’ life-span, the temperature of the environment and by precipitation, the affi nity of the vector to different hosts, and the ability of the vector to locate the host. Bluetongue has been spreading worldwide due to climatic changes and increasing average daily temperatures. The seasonal occurrences of the disease and the climate change have conditioned the need for adopting new strategies. The stochastic SEIRD mathematical model has been developed in order to simulate the transmission of the Bluetongue virus through the susceptible ruminant population on the territory of the Republic of Serbia, as well as to investigate the effect of climatic factors on the vector population and the magnitude of a possible epizootia. Besides the effects of climatic factors, we have analyzed a number of different approaches in the control of the disease based upon the vaccination of ruminants and control of vectors.