https://scidar.kg.ac.rs/handle/123456789/8207 2026-07-22T19:44:12Z https://scidar.kg.ac.rs/handle/123456789/23163 Title: Influence of lactation period and ketosis on blood ammonia in cows Authors: Cincović, Marko; Đoković, Radojica; Starič, Jože; Petrović, Miloš; Ježek, Jožica Abstract: Ammonia is a central component in ruminant nitrogen metabolism and serves as a sensitive indicator of the dynamic balance between nitrogen intake, rumen microbial activity, and hepatic detoxification efficiency. Once mproduced in the rumen, ammonia is absorbed into the bloodstream and must be rapidly cleared by the liver via the urea cycle. As such, blood ammonia concentration reflects both the rate of ammonia production and the liver’s detoxification capacity, making it a valuable marker for evaluating protein metabolism and liver function. This study aimed to assess how different lactation stages and the presence of ketosis/hepatic lipidosis affect blood ammonia levels in dairy cows. A total of 50 Holstein Friesian cows were examined, with 10 animals assigned to each experimental group. Ammonia levels (μmol/L) in blood plasma varied significantly depending on lactation stage and metabolic condition. In early lactation, the mean concentration was 67.64±6.52, which significantly decreased at peak lactation (34.11±7.5), followed by mid-lactation (29.93±7.9), and reached its lowest in the dry period (21.61±6.1). Cows diagnosed with ketosis exhibited significantly higher ammonia levels (96.52 ± 8.2). A significant positive correlation was found between ammonia and BHB (r = 0.54) as well as with the index of hepatocyte steatosis index (nonesterified fatty acid: cholesterol, NEFA:CHOL ratio) (r = 0.81), and significant negative correlations with the liver functionality index (r = –0.82), urea (r = –0.47), total protein (r = –0.38), and albumin (r = –0.36). These findings support the use of ammonia concentration as a reliable biomarker for metabolic and liver function assessment in dairy cows. 2026-01-01T00:00:00Z https://scidar.kg.ac.rs/handle/123456789/23161 Title: The presence of Phaeozems formed on loose parent materials in Serbia Authors: Životić, Ljubomir; Vasin, Jovica; Dugalić, Goran; Gajić, Boško; Knežević, Mirko Abstract: Phaeozems in the World Reference Base for Soil Resources (WRB) are thick, eutric soils which have a mollic horizon and lack secondary carbonates. The term ʼPhaeozemsʼ is not used in the National Soil Classification System (NSCS) in Serbia at any systematic level, but soils with these characteristics exist. The aim of this work was to compare the results of the national and international classifications of 18 soil profiles investigated at the toeslopes of Mountain Vukan, East-Central Serbia. The soils are mainly thick, formed on alluvial deposits, with a moderately high humus content, well-developed humus-accumulative horizons, and high base saturation. The WRB classification identified 16 profiles of Phaeozems;however, according to the NSCS, ten soil profiles correspond to Chernozems and eight to Eutric Cambisols. Five Cambic Chernic Phaeozems of the WRB correspond to Leached Chernozems and four to Eutric Cambisols. Three Cambic Phaeozems correspond to Leached Chernozems and two to Eutric Cambisols. In Serbia, Leached and Brownized varieties of Chernozems might be the closest to Phaeozems if they fulfill mollic and intermediate horizons criteria. In this work, we indicated that many Serbian soils may belong to Phaeozems, such as Calcareous and Gleyic varieties of Chernozems, Non calcareous and Calcareous Humofluvisols, etc. Soil investigation in the WRB requires detailed soil description and quantitative verification. The attempts to correlate the two systems in Serbia were not very accurate because of the missing data on soils. The importance of Phaeozems is outstanding because they are highly-fertile soils prone to degradation, which probably cover more than 300,000 ha or ~6% of agricultural land in Serbia. 2026-01-01T00:00:00Z https://scidar.kg.ac.rs/handle/123456789/23160 Title: Influence of organic biostimulants on morphological and biochemical traits of radish Authors: Pavlović, Nenad; Mladenović, Jelena; Živković, Ivana; Bošković-Rakočević, Ljiljana; Zornić, Vladimir; Stojanov, Dijana; Stevović, Vladeta; Tomic, Dalibor Abstract: The aim of this study was to evaluate the effects of different organic biostimulants on the morphological traits and quality parameters of radish under controlled growing conditions. The experiment was conducted with three replications and five treatments: Levoamin, Algafert, yeast, humic acids, and a control. The results showed that the application of biostimulants significantly affected all analysed morphological traits compared to the control. The highest values for plant height, total plant mass, and root dimensions were recorded in treatments with Levoamin and yeast. The application of biostimulants increased vitamin C content, total phenolic compounds, total antioxidant capacity, and total chlorophyll content. The most pronounced effect occurred with the yeast treatment, which recorded the highest values of total phenols and antioxidant capacity. The results indicate that applying organic biostimulants, particularly yeast, can significantly improve the growth and nutritional quality of radish. 2026-01-01T00:00:00Z https://scidar.kg.ac.rs/handle/123456789/23148 Title: Pest-specific chemical strategies for the management of Aleurocanthus spiniferus (Quaintance, 1903) in mandarin orchard supported by on-site chlorophyll assessment Authors: Đukanović, Mitar; Perović, Tatjana; Bursić, Vojislava; Tanasković, Snežana; Magazin, Nenad; Milić, Biserka; Baloš, Milica; Marinković, Dušan; Žunić, Antonije Editors: Undurraga, Pablo Abstract: In southern Montenegro, Aleurocanthus spiniferus (Hemiptera: Aleyrodidae) is an important Citrus pest. A field experiment was conducted in a Satsuma mandarin (Citrus unshiu Marcow.) orchard to evaluate the efficacy of chemical treatments for A. spiniferus control and to assess impact induced by this pest in plant leaves using portable chlorophyll meter-SPAD. Two insecticide applications were carried out, the first in June and the second in August in 2024 and 2025. During the first treatment in each season among all tested insecticides, deltamethrin, spirotetramat, pyriproxyfen and acetamiprid, the last mentioned showed the highest efficacy 7 d after treatment for larvae. During 2024, in the second treatment, pyriproxyfen showed highest efficacy of more than 91% 7 and 14 d after treatment, while acetamiprid showed the highest efficacy of more than 95% during the second trial in the second year. Spirotetramat showed high efficacy towards eggs in all except the first assessment during the first season. After both assessments in 2025, SPAD value was measured representing the chlorophyll content in mandarin leaves. In comparison to the control variant (49.9 SPAD units), the increase in chlorophyll content ranged from 38.2% to 48.6% (69.1-74.2 SPAD units) across all tested variants. The greatest positive impact was observed in the variant with spirotetramat (48.6%). Acetamiprid (45.6%) and pyriproxyfen (47.6%) values were also highly positive, while the smallest effect was recorded for deltamethrin (38.2%). The obtained results are consistent with high insecticide efficacy, i.e., the decreased chlorophyll levels within the control variant were caused by the higher pest infestation. 2026-01-01T00:00:00Z