Radmila Resanovic

Comparative investigation of the efficacy of three different adsorbents against OTA-induced toxicity in broiler chickens.

The aim of our study was to determine the efficacy of three different adsorbents, inorganic (modified zeolite), organic (esterified glucomannans) and mixed (inorganic and organic components, with the addition of enzymes), in protecting broilers from the toxic effects of ochratoxin A in feed. Broilers were fed diets containing 2 mg/kg of ochratoxin A (OTA) and supplemented with adsorbents at the recommended concentration of 2 g/kg for 21 days. The presence of OTA led to a notable reduction in body weight, lower weight gain, increased feed conversion and induced histopathological changes in the liver and kidneys. The presence of inorganic, organic and mixed adsorbents in contaminated feed only partially reduced the negative effects of OTA on the broiler performances. Broilers that were fed with adsorbent-supplemented feed reached higher body weight (17.96%, 19.09% and 13.59%), compared to the group that received only OTA. The presence of adsorbents partially alleviated the reduction in feed consumption (22.68%, 12.91% and 10.59%), and a similar effect was observed with feed conversion. The applied adsorbents have also reduced the intensity of histopathological changes caused by OTA; however, they were not able to prevent their onset. After the withdrawal of the toxin and adsorbents from the feed (21–42 days), all previously observed disturbances in broilers were reduced, but more remarkably in broilers fed with adsorbents.

MOLECULAR SEX DETERMINATION OF 20 BIRD SPECIES PROTECTED IN THE REPUBLIC OF SERBIA

Considering that more than 50% of bird species are monomorphic, the identification of gender based on phenotypic characteristics is extremely difficult. The aim of this study is sex determination in species inhabiting the Republic of Serbia, all under the state protection and declared by IUCN as endangered. DNA was isolated from feathers. Sex determination was based on sex-specific CHD gene amplified by 2550F/2718R primer set. Sexing gave good results in all 91 samples from 20 species including 6 species where molecular sexing has not previously been successful.

MOLECULAR CHARACTERIZATION OF SOME STRAINS OF NEWCASTLE DISEASE VIRUS ISOLATED IN PROVINCE OF VOJVODINA, REPUBLIC OF SERBIA

Five strains of Newcastle disease virus (NDV) were obtained from poultry in Vojvodina, Serbia during the outbreaks in 2006 and 2007. These isolates were confirmed and genotypically characterized by reverse transcription polymerase chain reaction (RT-PCR) with primer specific to the viral fusion (F) protein (572bp), and by sequencing of partial F gene for phylogenetic analysis. Phylogenetic analysis showed that all five isolated strains of Newcastle disease virus belong to genotype VII. At the same time, all five isolates were clustered in NDV subtype VIId. The examined NDV isolates express high similarity to each other (99.7-100%) and group together with the strains of Newcastle disease virus isolated previously from wild birds in Serbia during the same 2006 - 2007 outbreak. The analysis of the isolates F gene cleavage sites has shown that all five isolated strains of Newcastle disease virus had a cleavage site motif 112R–R–Q–K–R–F-117 characteristic for highly virulent, velogenic strains.

Gastroprotective effects of novel antidotal combination in rats acutely poisoned by T-2 toxin

The purpose of this experiment was to evaluate the antidotal potencies of methylprednisolone (soluble form, Lemod-solu®), nimesulide, N-acetylcysteine (Fluimucil®) and their combinations in rats treated with 1.0 LD50 (0.23 mg/kg) of trichothecene mycotoxin, T-2 toxin. Their antidotal efficacy was investigated by monitoring their effects on general condition, 24-hour-survival, body weight gain, food and water consumption and pathohistological changes in the gut of Wistar rats acutely treated with a single injection of T-2 toxin during a 4-week period. The highest protective index was obtained with methylprednisolone (2.43). Initial loss of body weight (after first 7 days) was found only in T-2 toxin group. During the whole experiment, in poisoned rats protected by methylprednisolone or methylprednisolone and nimesulide, a significant increase (p<0.001) in body weight gain, food and water consumption in comparison with T-2 toxin group was found. At the end of the experiment, N-acetylcysteine, nimesulide and their combination assured higher (p<0.05) weight gain, food and water consumption in comparison with T-2 toxin group. Signs of hemorrhagic diathesis and necrosis of the gut crypt epithelium and lymphoid tissues were found in the T-2 toxin group. Some of these histological alterations were presented in the gut of poisoned rats treated by nimesulide, Nacetylcysteine and their combination. The gut of T-2 toxin rats treated with a combination of methylprednisolone and nimesulide and especially methylprednisolone alone had a histological structure similar to the control group. These results clearly show that methylprednisolone, a well-known anti-inflammatory and immunosuppressive drug, exerts the best antidotal effect against T-2 toxin intoxication in rats.

Historical overview of methods for sex determination in birds

Determinacija pola ptica je komplikovana, prevashodno jer je preko 50% vrsta monomorfno (nema morfoloških razlika između polova). Pre primene molekularno genetičkih metoda, koristile su se brojne metode čija je glavna karakteristika da su nepouzdane. Zbog značaja analiza, one moraju biti pouzdane, ekonomične, bezbedne i brze. Visokokonzervativni CHD gen je definisan 1995. godine na W hromozomu ptica, dok je na Z hromozomu definisan dve godine kasnije. Razlika u dužini intronskih sekvenci CHD gena Z i W hromozoma, omogućava razlikovanje polova nakon amplifikacije specifičnih fragmenata primenom specifičnih prajmera. Molekularno genetičke metode imaju primat nad svim ostalim metodama jer osim toga što su bezbedne za izvođenje (i po pticu i po čoveka), daju pouzdane rezultate, a mogu se koristiti kod svih vrsta ptica.