János Oláh

Dr. János Oláh


Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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21 February 2020 in Animals
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BCBrigitta Csernus
Brigitta Csernus
SBSándor Biró
Sándor Biró
LBLászló Babinszky
László Babinszky
IKIstvan Komlosi
Istvan Komlosi
AJAndrás Jávor
András Jávor
LCLevente Czeglédi
Levente Czeglédi
This study was conducted to investigate the effect of carotenoid, oligosaccharide and anthocyanin supplementation in broiler diets under Escherichia coli lipopolysaccharide (LPS) challenge. Ross 308 chickens were fed 5 diets: basal diet (control diet), diet supplemented with β-glucan in 0.05% (positive control) and diets with 0.5% carotenoid-, oligosaccharide- or anthocyanin contents. On the 26th days of age, chickens were challenged intraperitoneally 2 mg LPS per kg of body weight. 12 h after injection, birds were euthanized, then spleen and ileum samples were collected. LPS induced increased relative mRNA expression of splenic (p = 0.0445) and ileal (p = 0.0435) interleukin-1β (IL-1β), which was lower in the spleen in carotenoid (p = 0.0114), oligosaccharide (p = 0.0497) and anthocyanin (p = 0.0303)-treated chickens compared to LPS-injected control birds. Dietary supplementation of carotenoids also decreased relative gene expression of splenic interleukin-6 (IL-6) (p = 0.0325). In the ileum, β-glucan supplementation showed lower relative mRNA expression of toll-like receptor 5 (TLR-5) (p = 0.0387) compared to anthocyanin treatment. Gene expression of both splenic and ileal interferon-α (IFN-α), interferon-γ (IFN-γ), toll-like receptor 4 (TLR-4) and toll-like receptor 5 (TLR-5) were not influenced by dietary supplements. In conclusion, carotenoids, oligosaccharides and anthocyanins could partially mitigate the immune stress caused by LPS challenge. All of the compounds impacted longer villus height (p < 0.0001), villus height:crypt depth ratios were higher after β-glucan (p < 0.0001) and anthocyanin (p = 0.0063) supplementations and thickened mucosa was observed in β-glucan (p < 0.0001), oligosaccharide (p < 0.0001) and anthocyanin (p = 0.048) treatments. All of these findings could represent a more effective absorption of nutrients.

11 August 2020 in Animals
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ESErika Szigeti
Erika Szigeti
JKJános Kátai
János Kátai
IKIstvan Komlosi
Istvan Komlosi
JOJános Oláh
János Oláh
CSCsaba Szabo
Csaba Szabo
Determination of wool mineral content to assess the animal’ mineral status has been extensively used, but the results are controversial. One of the possible contributing factors is that the sampling material in previous studies was collected from a long staple, a fact that could mask the response to recent differences in mineral intake. Therefore, the aim of the present study was to test the sensitiveness of newly grown wool to different dietary mineral intake. Twenty Tsigai ewes were allocated into five dietary treatments with similar hay and concentrate intake but different premix inclusion rates in the concentrate (3, 4, 5, 6, and 7%). Wool was sampled on the left side from a 5 × 5 cm area using bent scissors at the beginning of the trial and from the very same area 28 days later. Samples after cleaning and mineralization were analyzed with ICP-OES (Perkin-Elmer, Optima 3300 DV) for calcium, phosphorus, magnesium, sodium, selenium, zinc, copper, and sulfur content. Long fleeces had significantly lower Ca and Se content compared to the newly grown wool samples of the group at the premix manufacturer’s suggested level of supplementation (5%). Macrominerals in fresh wool did not respond to increased dietary supplementation. Se and Zn content of wool had a strong relationship with the daily intake (R2 = 0.95 and R2 = 0.97, respectively.) In conclusion, the mineral content of long fleeces can be different compared to recently developed wool fiber. This indicates that, in some cases, analyzing long staples for mineral status can be misleading. Our results showed that wool could be a sensitive indicator of low selenium and high zinc intake. Mineral interactions can significantly affect the actual availability of trace minerals; therefore, a more careful design of premixes is needed. The described method seems to be applicable in livestock farming, but the mineral interactions that may alter the results need to be further explored.

14 August 2022 in Animals
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Renáta KleinRenáta Klein
Renáta Klein
JOJános Oláh
János Oláh
SMSándor Mihók
Sándor Mihók
János PostaJános Posta
János Posta
The Mezőhegyes Stud was founded in 1784 where three different horse breeds were developed: the Furioso-North Star, the Gidran, and the Nonius. These breeds were based on the same mare population, but each breed had different utilization purposes. Our aim was to analyze the pedigree information of these three indigenous breeds. The genealogical information was traced back from the actual breeding population back to the founder animals, and the final database contained more than 47,000 horses. The reference populations were defined as the registered breeding animals in 2019. The complete generation equivalent was 16.45 for the Gidran breed, 15.18 for Furioso-North Star, and 12.64 for Nonius, respectively. Due to the utilization of English Thoroughbred during the breeding history, the average maximum generations were close to 36 generations for each breed. The average relatedness was approximately 4%. The average Wright’s inbreeding coefficient was the highest for the Nonius breed (5.59%). Kalinowski’s decomposition of inbreeding showed that inbreeding is originated mainly from the past; the current fixation of alleles was higher for the Nonius horse breed. There was a reasonable bottleneck effect for each breed. The estimated effective population sizes suggest that there is no problem with the maintaining of Mezőhegyes horse breeds.

28 July 2022 in Animals
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JLJames Kachungwa Lugata
James Kachungwa Lugata
JOJános Oláh
János Oláh
XOXénia Erika Ozsváth
Xénia Erika Ozsváth
RKRenáta Knop
Renáta Knop
EAEszter Angyal
Eszter Angyal
CSCsaba Szabo
Csaba Szabo
The study was carried out to determine whether sources or levels of methionine (Met) affect the health status of Tetra-SL (TSL) chicks by examining growth performance, feather growth, and hematological parameters. A total of ninety-six (96) day-old (44.2 ± 0.18 g lw) TSL chicks were randomly allotted to six treatment groups (three levels for each DL and L-Met source) with four replicates of four chicks each. Chicks were fed ad libitum diets supplemented with 90, 100, and 110% of methionine requirements for four weeks after hatch. The parameters examined are bodyweight (BW), average daily gain (ADG), feather length (FL), and hematological parameters, including: red blood cell (RBC) count, hemoglobin (Hb) concentration in the blood, hematocrit (Ht; %), number of white blood cells (WBC), platelet count, mean corpuscular volume of red blood cells (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), lymphocyte (LYM), mid-range (MID), and granulocyte (GRAN). There was no significant effect of Met sources and levels on BW, ADG, and FL of TSL chicks for the first four weeks of rearing. The RBC, Hb, Ht, WBC, LYM, MID, and GRAN values of TSL chicks were statistically influenced by dietary Met sources and Met levels (p < 0.05). Among the treatment groups, the number of white blood cells (WBC) on 90% DL–Met was the lowest. WBC, RBC, Hb, and Ht were higher from chicks that received 100% DL-Met than all other levels, regardless of the Met sources. The MCV, MCH, and MCHC values were not affected by either Met source or levels or their interactions. Met source and level interactively affected the Ht, WBC, LYM %, and GRAN values of TSL chicks (p < 0.05). The platelet number was affected by Met source only (p < 0.05) with chicks receiving L-Met source having more than twofold higher platelet values than DL-Met source. In conclusion, varying Met levels by ±10% of the requirement does not adversely affect the growth performance, feather growth, and hematological parameters of TSL chicks reared for up to four weeks of age. DL-Met increased the body weight and improved the white blood cells, red blood cells, and hematocrit at 28 days after hatch. DL-Met showed similar biological efficacy as L-Met for body weight and feather growth but not for the hematological parameters.

18 April 2025 in Agriculture
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EBEszter Ilona Bácsi
Eszter Ilona Bácsi
Renáta KleinRenáta Klein
Renáta Klein
András LévaiAndrás Lévai
András Lévai
FKFiona Kenyon
Fiona Kenyon
JOJános Oláh
János Oláh
In this study, we analysed scrapie test results of Hungarian indigenous sheep breeds (Cikta, Tsigai, Dairy Tsigai, Transylvanian Racka, and Hungarian Racka in white and black colour variants) and the endangered Hungarian Merino rams during the period from 2019 to 2023. In Hungary, it is mandatory to perform scrapie testing for every ram intended for breeding. These results were subsequently compared with data from analyses conducted in 2004 and between 2013 and 2015, which served as control samples. The test results were given by the Hungarian Sheep and Goat Breeders’ Association. The employees collected ear cartilage tissue samples during the identification of the lambs using TypiFixTM by Agrobiogen GmBH. We determined the frequencies of alleles, genotypes, and risk groups, and calculated the proportion of each within the studied population. The scrapie test results were evaluated using the SPSS 23 software package and a Chi2-test. Samples were categorised into one of five risk groups (R1 (lowest)–R5 (highest)) based on the degree of resistance observed. In conclusion, we found that there was a significant improvement in scrapie susceptibility for all breeds except the Cikta. However, the potential impact of this improvement on other important traits remains undetermined. Regarding susceptibility to scrapie, the Hungarian Merino is the most resistant group, as 68.8% of the rams in this breed belonged to the R1 risk group, while the Cikta sheep is in the least favourable position, as only 3.3% of the examined individuals belonged to this category.

13 May 2025 in Animals
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BBBrigitta Barsi
Brigitta Barsi
JOJános Oláh
János Oláh
János PostaJános Posta
János Posta
The Hungarian Coldblood horse was developed in the 1920s by crossing local mares with draft horses imported from Belgium and France, and was approved as an official horse breed in 1954. The aim of the study was to analyze the quality of the pedigree, generation interval, gene origin, and inbreeding. The pedigree information was received from the Hungarian Coldblood Horse Breeding Association. The studbook data of the registered animals up to 2023 were evaluated. Two reference populations were chosen: horses having offspring in 1989 and 2023. The final database contained 21,699 horses. Pedigree data of the total population and the actual breeding stock were analyzed using Endog 4.8. and Grain 2.2. software. The complete generation equivalent was 4.64 and 7.72, whereas the average maximum generations was 7.90 and 13.06 for the total and reference population, respectively. There were significant differences between the parent–offspring pathways of generation intervals. In the total stock, the first 10 individuals are present in 26.71%, while in the actual breeding stock, they are present in 37.84%. The average Wright’s inbreeding coefficient was 1.13% and 2.35% in the total population and the actual breeding stock. Kalinowski’s new decomposition of inbreeding showed that inbreeding does not originate from the past; inbreeding is stronger in more recent generations. There was a reasonable bottleneck effect. A more careful mating design might be needed to avoid inbreeding in the future.