B. Petrujkic

Effects of selenium supplementation as sodium selenite or selenized yeast and different amounts of vitamin E on selenium and vitamin E status of broilers.

The aim of this experiment was to determine the effects of broiler meal supplementation with different forms of selenium (as Na-selenite or selenized yeast) and different amounts of vitamin E on selenium and vitamin E status in broiler tissues. A total number of 240 broilers (Cobb 500) were divided in four experimental groups supplemented with Se and vitamin E for a period of 42 days: group SS+E20 - 0.3 mg/kg sodium selenite and 20 IU of vitamin E; group SY+E20 - 0.3 mg/kg selenized yeast and 20 IU of vitamin E; group SS+E100 - 0.3 mg/kg sodium selenite and 100 IU of vitamin E; group SY+E100 - 0.3 mg/kg selenized yeast and 100 IU of vitamin E. Blood plasma Se and MDA concetrations and Se dependent GSH-Px were determined on days 1, 21 and 42, wheres content of Se and vitamin E in breast muscle and liver were measured on days 21 and 42 of the experiment. Highest blood plasma glutathione peroxidase (GSH-Px) activities were detected in groups SS+E20 and SS+E100. Supplementation with selenium enriched yeast did not result in a significant increase in plasma GSH-Px activity. Selenium and vitamin E concentrations in breast meat and liver were significantly higher in groups supplemented selenized yeast compared to those receiving Na-selenite. Selenium and vitamin E supplementation did not alter plasma MDA concentrations, but in tissues, selenized yeast provided a consistent, although not significant, reduction in MDA content. The increased dose of vitamin E supplemented in broiler meal was not justifiable on the basis of vitamin E tissue content and antioxidative effect.

Comparative effect of thymol or its glucose conjugate, thymol-β-d-glucopyranoside, on Campylobacter in avian gut contents

Campylobacter jejuni is an important human food-borne pathogen that can contaminate meat and poultry during processing. Consequently, strategies are sought to reduce the carriage of C. jejuni in food animals before they arrive at the abattoir. Thymol is a natural product that reduces survivability of Campylobacter in vitro, but its rapid absorption from the proximal alimentary tract limits its bactericidal efficacy in vivo. Thymol-β-d-glucopyranoside is more resistant to absorption than free thymol, but its administration to chickens has not been reported. In the present studies, 1 mM thymol-β-d-glucopyranoside was shown to exhibit near equal anti-Campylobacter activity as 1 mM thymol when incubated anaerobically in avian crop or cecal contents in vitro, resulting in reductions of 1.10–2.32 log10 colony forming units mL−1 in C. jejuni concentrations after 24 h incubation. In a follow-up live animal study, oral administration of thymol-β-d-glucopyranoside, but not free thymol, significantly lowered (>10-fold) recovery of Campylobacter from the crop of market-aged broilers when compared to placebo-treated controls (n = 6 broilers/treatment). Neither thymol-β-d-glucopyranoside nor thymol affected recovery of Campylobacter from cecal contents of the treated broilers. These results indicate that rapid absorption or passage of free thymol from the crop precluded its anti-Campylobacter activity at this site and throughout the entire gastrointestinal tract. Conversely, lower recovery of Campylobacter from the crop of birds treated with thymol-β-d-glucopyranoside indicates this conjugate was retained and able to be hydrolyzed to biologically active free thymol at this site as intended, yet was not sufficiently protected to allow passage of efficacious amounts of the intact glycoside to the lower gut. Nevertheless, these results warrant further research to see if higher doses or encapsulation of thymol-β-d-glucopyranoside or similar glycosides may yield an efficacious additive to reduce carriage of Campylobacter as well as other pathogens throughout the avian gut.

Ex vivo absorption of thymol and thymol-β-D-glucopyranoside in piglet everted jejunal segments.

Food-producing animals are reservoirs of Campylobacter, a leading bacterial cause of human foodborne illness. The natural product thymol can reduce the survivability of Campylobacter, but its rapid absorption in the proximal gastrointestinal tract may preclude its use as a feed additive to reduce intestinal colonization of these pathogens. This work examined the ex vivo absorption of thymol and thymol-β-d-glucopyranoside in everted porcine jejunal segments, as the latter was hypothesized to be more resistant to absorption. A modified gas chromatography and extraction method was developed to determine 1.0-500 mg/L thymol. From 1 and 3 mM solutions, 0.293 ± 0.04 and 0.898 ± 0.212 mM thymol, respectively, p = 0.0347, were absorbed, and 0.125 ± 0.041 and 0.317 ± 0.143 mM thymol-β-d-glucopyranoside, respectively, p = 0.0892, were absorbed. Results indicate that thymol-β-d-glucopyranoside was absorbed 2.3 to 2.8 times less effectively than thymol, thus providing evidence that thymol-β-d-glucopyranoside may potentially be used as a feed additive to transport thymol to the piglet lower gut.

Influence of phytogenic feed additive on Lawsonia intracellularis infection in pigs

Lawsonia intracellularis is known to cause proliferative enteropathy (PE), one of the economically most important swine diseases with global distribution. Not unlike other enteric diseases, PE is a frequent indication for antibiotic therapy. However, their unjustified use leads to an emerging problem - antimicrobial resistance. Thus, the aim of this research was to assess if a phytogenic additive may replace antibiotics in the control of PE in 144 weaned piglets (72 treated and 72 controls) naturally infected with L. intracellularis. The quantity of L. intracellularis faecal shedding was monitored by real-time polymerase chain reaction (PCR) assay in faecal samples on day 0, 14 and 28, whilst the level of the ileum damage was determined by immunohistochemistry (IHC) assay performed on gut sections. Real-time PCR assay revealed that cycle-threshold (Ct) values in the treatment group increased significantly over time and were higher than in the control. These results indicate that the use of the phytogenic additive decreases the faecal excretion of L. intracellularis both throughout the experiment and in comparison to the control. The expression of the L. intracellularis antigen in IHC assay was lower in treated animals, implying that the additive leads to the decrease in the pathogen quantity in the ileum. Significantly higher feed conversion ratio was recorded in the treatment group. The results indicate that the phytogenic additive may be beneficial in the control of PE, but additional research is necessary to assess its use in various pig categories and define the optimum concentrations.

Validation of 10 Microsatellite Loci for Their use in Parentage Verification and Individual Identification in the Yugoslavian Shepherd Dog Sharplanina / Walidacja 10 Loci Mikrosatelitarnych Do Kontroli Pochodzenia Oraz Identyfikacji Osobniczej Jugosłowiańskiego Psa Pasterskiego Z Szar Płaniny

Abstract The aim of the study was to assess a commercially available microsatellite panel for use in paternity and identification analyses in the Yugoslavian Shepherd Dog Sharplanina, an ancient livestock guarding breed. Allele frequencies for 10 microsatellite loci (PEZ01, FHC2054, FHC2010, PEZ05, PEZ20, PEZ12, PEZ03, PEZ06, PEZ08 and FHC2079) were determined in 103 unrelated Yugoslavian Shepherd Dog individuals. The loci revealed varied levels of polymorphism (five to 12 alleles), with an average of 7.83 per locus. Average values of observed heterozygosity and polymorphic information content (PIC) were 0.64 and 0.66, respectively. Nine out of 10 microsatellite markers were highly informative with PIC values higher than 0.5. The obtained value of combined power of exclusion (0.9989) confirms usefulness of this panel of microsatellites for parentage verification, while the value of combined power of discrimination of 0.9999 clearly shows that the panel can conclusively identify individual dogs. In conclusion, the results obtained suggest that the selected set of commercially available microsatellite markers may be used as a routine tool for parentage verification and individual identification in the Yugoslavian Shepherd Dog. Although analysis of genetic variability of the Yugoslavian Shepherd Dog was not the primary focus of the study, the established values of major diversity indices disclose a highly variable gene pool in the breed. Streszczenie Celem eksperymentu była ocena przydatności komercyjnego panelu markerów mikrosatelitarnych do analizy pochodzenia i identyfikacji osobniczej owczarka jugosłowiańskiego Sarplaninac, starodawnej rasy psów pasterskich. Frekwencje alleli dla 10 loci mikrosatelitarnych (PEZ01, FHC2054, FHC2010, PEZ05, PEZ20, PEZ12, PEZ03, PEZ06, PEZ08 i FHC2079) określono u 103 niespokrewnionych osobników rasy Sarplaninac. W loci ujawniono zróżnicowany poziom polimorfizmu (5 do 12 alleli), wynoszący średnio 7,83 na locus. Średnie wartości heterozygotyczności obserwowanej i współczynnika polimorfizmu (PIC) wyniosły, odpowiednio 0,64 i 0,66. Dziewięć z 10 markerów mikrosatelitarnych było wysoko informatywnych, przy wartościach PIC przekraczających 0,5. Uzyskana wartość skumulowanej siły wykluczenia (0,9989), potwierdza przydatność badanego panelu markerów mikrosatelitarnych do kontroli pochodzenia, natomiast wartość skumulowanej siły dyskryminacji, wynoszącej 0,9999 wyraźnie wskazuje, że panel ten może jednoznacznie identyfikować poszczególne osobniki. Uzyskane wyniki wskazują, że wybrany zestaw komercyjnych markerów mikrosatelitarnych może służyć jako rutynowe narzędzie do kontroli pochodzenia oraz identyfikacji osobniczej jugosłowiańskiego psa pasterskiego. Choć analiza zmienności genetycznej owczarka jugosłowiańskiego nie była głównym celem badań, uzyskane wartości głównych indeksów różnorodności wskazują na występowanie wysoko zróżnicowanej puli genowej w tej rasie.

Determining the value of Vlashko-Vitoroga Zackel sheep for the conservation process

Autochthonous Pramenka (Zackel) sheep has been recognized as an important element of regional agro-biodiversity, relevant to the tradition that encompasses the cultural heritage of Serbia. The recognition that locally adapted animal breeds gained genetic resistance and adaptability through evolution; modern sustainable farming practices are far more attuned to the need for preserving and utilizing Zackel sheep types. The risk factors leading to rapid and severe decline in Vlashko-Vitoroga Zackel sheep population have been described in the paper. The objective of the study was to obtain the data necessary for development of conservation and sustainable use strategies of Vlashko-Vitoroga Zackel sheep. Determination of the conservation value upon characteristics of the breed was performed, in aim to identify priorities in accordance with the criteria of Food and Agriculture Organization of the United Nations (FAO). The positive and negative characteristics of the Vlashko-Vitoroga Zackel sheep, opportunities for utilization, as well as ambiental challenges that affect the breed were analyzed in the paper. The importance of this breed for maintenance of cultural tradition, landscape preservation and longterm rural development by in-situ conservation through utilization is also discussed in the paper. [Projekat Ministarstva nauke Republike Srbije, br. TR31085]

The analysis of forage quality for organic milk production in Fruška Gora region.

As a result of the growing demand for organic products, especially organic milk, the livestock organic production has increased. In this paper botanical and chemical composition of forage for organic diary cow production in Fruska Gora region were analysed. In the mixed hay samples, species from the Poaceae family were classified, according to their nutritive value into the first class. Dominant presence of Dactilys glomerata L. and Poa pratensis was revealed. Lucerne hay was predominantly composed only by one leguminous species Medicago sativa L. Basic nutritive components of mixed and Lucerne hay: crude moisture, crude ash, crude protein, crude fat, crude cellulose, calcium (Ca), magnesium (Mg) phosphorous (P), copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn) were determined. Determined levels of hazardous and noxious substances (mycotoxins, pesticides and heavy metals) in all hay samples were in the range according to regulations. Botanical analysis has confirmed the presence of plants with high yield and of high nutritive value. Chemical analyses of hay samples originating from Fruska Gora has pointed out that the level of crude proteins, cellulose, fats, macro and trace elements can completely satisfy the requirements of animals in organic farming and therefore can present a solid base for further development of organic dairy farming.

Nigella sativa L. as an alternative antibiotic feed supplement and effect on growth performance in weanling pigs: Nigella sativa feed supplement in weanling pigs

BACKGROUND Nigella sativa L. (NS) is a plant containing bioactive constituents such as thymoquinone. Extracts of NS improve performance and reduce enteropathogen colonization in poultry and small ruminants, but studies with swine are lacking. In two different studies oral administration of NS extracts at doses equivalent to 0, 1.5 and 4.5 g kg-1 diet was assessed on piglet performance and intestinal carriage of wildtype Escherichia coli and Campylobacter, and Salmonella Typhimurium. RESULTS Wildtype E. coli populations in the jejunal and rectal content collected 9 days after treatment began were decreased (P ≤ 0.05). Populations recovered from pigs treated with extract at 1.5 and 4.5 g kg-1 diet were 0.72-1.31 log10 units lower than the controls (ranging from 6.05 to 6.61 log10 CFU g-1 ). Wildtype Campylobacter and Salmonella Typhimurium were unaffected by NS treatment. Feed efficiency over the 9 days improved linearly (P < 0.05) from 3.88 with 0 NS-treated pigs to 1.47 and 1.41 with pigs treated with NS at 1.5 and 4.5 g kg-1 diet, respectively, possibly due to high glutamine/glutamic acid content of the NS extract. CONCLUSION NS supplementation of weanling pigs improved feed efficiency and helped control intestinal E. coli during this vulnerable production phase.

A molecular genetic approach to roebuck individual identification in the case of poaching in Serbia

Application of the molecular genetic methods in forensic cases dealing with wild animals has significantly increased recently. These techniques are practically used in order to help solving four key problems : determination of kind of the wild animal, geographic origin, kinship ties and individual identification. In this work the first case of introducing the examination of polimorphism of microsatelite genetic markers within forensic analysis in the cases of poaching in Serbia is presented. The objectives of this forensic analysis was to determine if the meat confiscated during house search of the suspect comes from roebuck origin (Capreolus capreolus), which remains had been found by a game warden in the field during closed season, where the suspect denied the offense, claiming that the meat comes from other roebuck that had been shot during the previous hunting season. DNK was isolated from the skin and fur samples taken from the roebuck corpse found in the woods, as well as from the frozen meat found in the suspect’s house. Both amplification and polimorphism examination of the eight microsatelite markers (ROE01, NVHRT21, NVHRT24, NVHRT48, NVHRT73, RT7 AND RT27) were carried out. In all the examined samples, the same pattern of variability of the tested microsatelites was determined, that is it was proved that DNK profiles of the samples taken from roebuck corpse were identical to DNK profile of the meat sample found in the suspect’s house. This result clearly indicates that all the examined biological samples originate from the same animal, and consequently represents forensically valid evidence in the case of roebuck poaching. [Projekat Ministarstva nauke Republike Srbije, br. III46002]

The nutritive value of Valjevac grassland - zasavica reservation.

Valjevac pasture of Zasavica reservation with its area of 300 ha presents a significant area for grazing cattle. In order to evaluate its potential for livestock production, the botanical and chemical composition of hay in three different time periods was observed (spring, summer and autumn). The determined plants species confirmed the richness of Zasavica grasslands, as well as the presence of dry, moist and forest habitat plants. The analyzed plants mostly belong to the Poaceae, Fabaceae, Asteraceae and Plantaginaceae families. Chemical analysis determined that the protein content decreased (P<0.01) from April (17.22±0.40 %) to October (10.30±0.16 %), and cellulose content increased (P<0.01) (from 19.07±0.38 % in April to 21.65±0.41 % in October). The calculated energy density of hay samples ranged from 0.425 Starch Units (SU) in October, 0.443 SU in April to 0.448 SU in June. The Valjevac pasture with its numerous plant species is of great importance in upkeeping biodiversity and also presents a solid base for livestock production. The determined levels of manganese and copper point out to the need of copper supplementation especially during the late summer and autumn periods. [Projekat Ministarstva nauke Republike Srbije, br. III46002]