risto uzunov | Ss. Cyril & Methodius University in Skopje (original) (raw)

Papers by risto uzunov

Ram spermatozoa motile and metabolic activity – potentially predictable pattern of ejaculate fatt... more Ram spermatozoa motile and metabolic activity – potentially predictable pattern of ejaculate fatty acid composition Spermatozoa contain considerably high proportion of polyunsaturated fatty acids (PUFA) thus being prone to peroxidation (PO). According to the " membrane pacemaker theory " , regarding spermatozoa, we hypothesized that fatty acid (FA) composition in the ejaculates could dictate spermatozoa metabolic profile whilst retaining vitality and resilience to PO. Samples were collected from four high performing rams (Pramenka) by artificial vagina. Standardized cell concentrations (~300x106 in TRIS-PBS) were evaluated on CASA for compliance with velocity (VSL-μ/s) and linearity index (STR) cutoff nominal values (VSL ≥60, STR ≥0.8). Total of 91 ejaculates have been categorized in three groups: A (not complying with either nominal), B (complying with one nominal), and C (complying with both nominal), each containing 18, 36 and 37 samples, respectively. FA values have be...

Recent studies have shown that dietary fat is gainful to the reproductive performance of dairy co... more Recent studies have shown that dietary fat is gainful to the reproductive performance of dairy cows. Polyunsaturated fatty acids (PUFA) are considered significantly important since they are involved in prostaglandin synthesis and steroid metabolism. Our preliminary study of serum fatty acids composition reveals significantly lower concentration of total serum lipids and PUFA’s in cows with ovarian disorders. The aim of this study was to evaluate differences between fatty acid content in follicular fluid (FF) and blood serum of cows with ovarian failures (cysts or static ovaries). Ten high yielding dairy cows from one farm were selected for this study during routine gynecological investigation by ultrasound. Group 1. (n=5) consists of animals with cystic follicles (> 22 mm of inner diameter) and group 2. of cows more than 60 days p.p. (n=5) with static ovaries (largest follicle <10 mm). Follicular fluid sampling was done by ultrasound-guided transvaginal follicle aspiration usi...

Macedonian Veterinary Review, 2015

Fatty acid composition of foods has a great impact on nutrition and health. Therefore, thе determ... more Fatty acid composition of foods has a great impact on nutrition and health. Therefore, thе determination and knowledge of the fatty acid composition of food is very important for nutrition. Due to the high nutritional characteristics of ostrich meat and its products, the research determining their quality is of topical interest. The aim of the present investigation was the determination of fatty acid composition of ostrich adipose tissue. The content of fatty acids was determined according to AOAC Official
Methods of Analysis and determination was performed using a gas chromatograph with a flame-ionization detector (GC-FID). The results are expressed as a percentage of the total content of fatty acids. The method was validated and whereupon the
following parameters were determined: linearity, precision, recovery, limit of detection and limit of quantification. The repeatability was within of 0.99 to 2.15%, reproducibility from 2.01 to 4.57%, while recovery ranged from 94.89 to 101.03%. According to these results, this method is accurate and precise and can be used for analysis of fatty acids in foods. It was concluded that the content of saturated fatty acids (SFA) accounted 34.75%, of monounsaturated fatty acids (MUFA) 38.37%, of polyunsaturated fatty acids (PUFA) 26.88%, of total unsaturated fatty acids (UFA) 65.25% and of desirable fatty acids (DFA) (total unsaturated + stearic acid) 70.37% of the analysed samples. The ratio polyunsaturated/saturated fatty acids accounted 0.77. The most present fatty acid is the oleic (C18:1n9c) with 28.31%, followed by palmitic (C16:0) with 27.12% and linoleic (C18:2n6c) acid with 25.08%. Other fatty acids are contained in significantly lower quantities.

Pollution of surface water presents the major ecological problem in developed industrial world. V... more Pollution of surface water presents the major ecological problem in developed industrial world. Various human activities lead to the deterioration of water quality and mining presents one of those impacts. This need for resources has been proven to have extremely negative influence on all biological as well as physico-chemical characteristics of water. Animals that inhabit waters under severe mining activity diversely respond to environmental changes. The changes of hematological parameters in fish can present the consequences of mining influence on the river water. The objective of this study was to determine how mining activity influence hematological parameters in Vardar chub (Squalius vardarensis). Samples from three rivers in the north-eastern Macedonia were obtained: two under mining influence, Zletovska and Kriva River and Bregalnica River as a non-impacted one. Comparison of the values of hematological parameters (hematocrit (HCT), total serum protein (TSP), refractive index...

The Journal "Agriculture and Forestry", 2015

The purpose of this research was focused on determination of the concentrations of activity of 22... more The purpose of this research was focused on determination of the concentrations of activity of 226 Ra, 232 Th, 40 К and 137 Cs in the soil samples collected from cultivated soil close to several larger cities in the Republic of Macedonia (Tetovo, Veles, Bitola) by using gamma spectrometry. Data show that the average value of activity of 226 Ra and 232 Th are within the range of (25.58-36.48) and (36.55-50.45) Bq kg -1, respectively. While, the concentrations of activity of 40 К in comparison to those obtained for 232 Th and 226 Ra are higher in all analyzed soils samples, showing values within the range of (611.59-781.23) Bq kg -1, the activities of 137 Cs are generally lower and are within the range of (9.33-18.90) Bq kg -1, with the highest activity at a depth of 5 cm, which is well in accordance with the data from the literature. However, 40 К is the only radionuclide which was determined with a significant quantity in the soil samples, and for which one can tell that in all loca...

ff#:*ffiH::Xi*ffi11 ll*,.;:j':-tvpe ror examination because thev absorb minerars, and with.that t... more ff#:*ffiH::Xi*ffi11 ll*,.;:j':-tvpe ror examination because thev absorb minerars, and with.that they can not avoid the time or semi-decul 9r '"c,, ,ili;, r;'."1ilJ,"i'frilH tf:,H:llfi:ffi[1]rs rhe p,.po,.

Veterinary drugs are widely used in modern animal husbandry. Their usage is not only for therapeu... more Veterinary drugs are widely used in modern animal husbandry. Their usage is not only for therapeutic and prophylactic purposes but also for better breeding efficiency. A part of veterinary drugs are used as growth promoters in form of specified compounds or mixtures of compounds. Therefore, among other compounds, steroids and other substances that have similar pharmacological activity are used to improve efficiency of protein conversion. As a result of enhanced protein conversion the growth of animals is faster which lead to earlier slaughter. The aim of this study was to detect levels of β – agonist residues since they are used as additives in the feed. By using ELISA method level of β – agonist was determinate. Total of 49 feed samples were screened for the presence of β–agonist as a part of national monitoring residue plan. The feed samples were collected and delivered by the authorised veterinary inspectors within period of 1 year. The validation process was carried out accordin...

ffi*t'"11}.fit"ffi1:?ffiJe like substances have been recentlv used in livestock production to obt... more ffi*t'"11}.fit"ffi1:?ffiJe like substances have been recentlv used in livestock production to obtain a high yield These anabolic agents are used to increase the weight gain, to improve the food efficiency, storing protein and to decrease fatness" But' depending on the use of anabolic in animal r""a,"rrouolic iesidues tirat may occur in meat and meat products present risks to human health. The present study was undertaken io deteci and quanti$z the [veh of trenbolon. ."riar", (a potent synthetic analog of testosterone) in meat in Republic of Macedonia. cattle meat samples were collected within period of 12 months as they were delivered by the authorised veterinary inspectors' a totui or 82 samples or.uttr. meat were anaryzed.for revel of trenbolone by Enzyme-Linked Immunosorbant Assay method. The detection limit was 91.5 ppi ro, the assay. The overal recoveries and the coefficientsofvariation(cvs)wereintherange of83.7%-99.6Yoand,4.!o/-o-.g.2%,respectivery,aworkingrangebetwe en25to4o0 ppt, and the regression equation of the nnar iirutit;;r;;;; s: y: _0.2451x + 1.[221,I,,2:0.992e. ite average experimental value of trenbolone in meat was 152'2ppt'-This uutu. gou" oo evidence.for trr. il"g"i use of hormon"s i, Republic of Macedonia, but these results do not exclude tte possiuitity of misuJe ortrr.r" potentiaily trarmdt chemicals in future. The."for. it is necessary to conduct permanent control of these hormones. as a food quality and health safety measure.

C o rre sp o nding autho r : zhajrulai@fu m. ukim. e du. mk AESTRACT zeranol is a synthetic deriv... more C o rre sp o nding autho r : zhajrulai@fu m. ukim. e du. mk AESTRACT zeranol is a synthetic derivative of zearalenone which has been used as an anabolic substance in sheep and cattle to increase growth at food producing animals. The usage of zeranol is prohibited in most countries of the European Union and in Macedonia. In the illegal use of zeranol it is difficult to determine its piesence because the amount of zeranol given and period is not known. A high affinity polyclonal antibody-based enzyme linked immunosorbent assay (ELISA) was developed for the quantification of zeranol in bovine urine' In the improved ELISA, the linear response range was between 0.025 and 3 ng/ml , and the aetectlonlimi;;", 0'22ng/ml for the assay. The overall recoveries and the coefficiints of variation (CVs) *"r. ii the range of gi.9%-92.3%o and 2'4%-5 '6%, respectively. Thirry-six bovine urine samples spiked with zeranol (ranging from 0.2 to 10 ng/ml) were detected by the ELISA, and good correlations was obtaine d (R'z=O.99i9) we conclude that this imiroved ELISA is suitable tool for a mass zeranol screening method for zeranol in bovine urine. A total of 87 bovine urine sampl., *.r. screened for the presence of zeranol as part of national monitoring residues where these documented cases presented zeranolconcentrations were much lower than the MRpL !!t by the according the guidance letter from Community Reference Laboratories, ( 7 December 2oO7).

A total of 635 muscle and kidney samples were collected during 2010 and 2011 atslaughter houses w... more A total of 635 muscle and kidney samples were collected during 2010 and 2011 atslaughter houses within the monitoring plan for food from animal origin in Macedonia-The tissue samples were examined for chroramphenicol, sulfonamides, quinolones and tetracyclines' Enzyme-linked immunosorbent method, *.r. used for the determination of chloramphenicol, sulfonamides and quinolones' and high performance liquid chromatography with Diode Array detection was applied for screening of tetracyclines.

A total of 497 raw milk samples collected at individual farms and collection tanks for milk from ... more A total of 497 raw milk samples collected at individual farms and collection tanks for milk from eight regions from Macedonia were examined for chloramphenicol, sulfonamides, quinolones and tetracyclines from October 2008 until April 2011. Immunoassay methods were used for the determination of chloramphenicol, sulfonamides and quinolones, and high performance liquid chromatography with Diode Array detection was applied for screening of tetracyclines. The methods were validated according to the recommendations laid down by European Commission Decision 2002/657/EC. The obtained data confi rmed that the methods were appropriate for detection of antibiotics determined, at the concentration level of interest. Measured range of concentrations (in μg/kg) was 13.5-147.9 for sulfonamides, 0.6-22.0 for quinolones and 17.4-149.1 for tetracyclines, with calculated mean values (in μg/ kg) 24.7 for sulfonamides, 12.6 for qinolones and 41.9 for tetracyclines. None of the analyzed samples showed pr...

Macedonian Veterinary Review, 2015

The Journal "Agriculture and Forestry", 2015