Jožica Ježek

Dr. Jožica Ježek


Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

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

Representative Publications

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1 March 2018 in Journal of Swine Health and Production
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Journal Article
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JJJolica Jelek
Jolica Jelek
JSJole Stark
Jole Stark
MNMarija Nemec
Marija Nemec
JPJan Plut
Jan Plut
IOIrena Golinar Oven
Irena Golinar Oven
JSJože Starič
Jože Starič
Objectives: To evaluate influence of age, farm, and physiological status on pig hematological profiles. Materials and methods: This study was carried out on five 1-site, farrow-to-finish pig farms in Slovenia, where a total of 382 clinically normal pigs were sampled. All farms were free of Aujeszky’s disease (pseudorabies), classical swine fever, and porcine reproductive and respiratory syndrome. Blood samples were taken from the anterior vena cava. Hematological analyses were performed with an automated hematological analyser. The following hematological variables were measured: red blood cell count (RBC), white blood cell count (WBC), hematocrit (Hct), hemoglobin concentration (Hb), erythrocyte indices, and platelet count (PLT). Differential WBC counts were determined manually using stained smears. Results: The farms themselves influenced all of the investigated variables except RBC and WBC differential (ie, lymphocytes, monocytes, and band neutrophils). A trend of lower values of RBC, Hb, and Hct, higher WBC numbers, and a higher percentage of segmented granulocytes were observed in lactating sows when compared to pregnant sows. Age significantly influenced hematological values and differential WBC counts except basophils, monocytes, and band neutrophils. Values of mean corpuscular volume (MCV) increased with age, the highest values being found in sows. Numbers of WBC and PLT decreased with age, the lowest number being observed in sows. Implications: Hematological examination may be an important diagnostic tool in the assessment of pig health status, but to interpret the results properly, it is important to consider pig age, health history, and clinical data.

26 September 2017 in Polish Journal of Veterinary Sciences
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Journal Article
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JJJožica Ježek
Jožica Ježek
MCM.R. Cincović
M.R. Cincović
MNM. Nemec
M. Nemec
BBB. Belić
B. Belić
RDR. Djoković
R. Djoković
Jože StaričJože Starič
Jože Starič
Ketosis is a very frequent metabolic disease in dairy cows, resulting in lower milk production, impaired fertility and increased frequency of other diseases. The course of the disease is often subclinical, so early detection is very important. The aim of the study was to investigate the relation between the concentration of beta-hydroxybutyrate in blood and milk and to determine the cut-off value in milk for detection of subclinical ketosis. The study included 94 cows, which were in the first third of lactation. Beta-hydroxybutyrate (BHB) concentrations were measured in blood and milk serum using a biochemical analyser. The average concentration of BHB in the blood serum samples was 1.14 mmol/L while in the milk it was about ten times lower at 0.117 mmol/L. A statistically significant positive correlation between the concentration of BHB in blood and milk (r=0.705, p<0.001) was found. In cows with BHB in blood below 2.0 mmol/L a stronger correlation between blood and milk BHB was established (r=0.658, p<0.001) than in cows with blood BHB above 2.0 mmol/L (r=-0.292, p=0.206). Therefore, BHB in milk is a very suitable indicator in the diagnosis of subclinical ketosis as there is a good correlation between BHB in the blood and milk of cows with subclinical ketosis. The cut-off concentration of BHB in milk set at ≥0.080 mmol/L (AUC=0.91±0.03; p<0.001) is a significant indicator for subclinical ketosis in dairy cows. The sensitivity of the test was 94% and specificity 74%. Beta-hydroxybutyrate in milk is a good indicator of subclinical ketosis in dairy cows and can be measured accurately with a biochemical analyser.

10 November 2022 in Metabolites
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SKSrđan Krnjaić
Srđan Krnjaić
Marko CincovićMarko Cincović
Marko Cincović
RDRadojica Djokovic
Radojica Djokovic
BBBranislava Belić
Branislava Belić
JJJožica Ježek
Jožica Ježek
Jože StaričJože Starič
Jože Starič
Increasing milk production requires increasing milking frequency (MF) from two times daily (2X) to three (3X) or more. High milk production leads to negative energy balance (NEB) and homeorhesis, characterized by lipolysis, ketogenesis, and endocrinological changes. The relationship among energy balance (EB), lipolysis, and ketogenesis with endocrine and metabolic parameters in blood of cows milked 2X and 3X daily was studied. Holstein Friesian cows milked 2X (n = 45) and 3X (n = 45) were analyzed, with approximately 50% of cows in each group in positive EB (PEB) and 50% in NEB. After determining EB, blood samples were collected from all cows and blood serum was analyzed for non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHB), glucose (GLU), cholesterol (CHOL), triglycerides (TGC), total bilirubin (TBIL), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), calcium (Ca), inorganic phosphate (P), total protein (TPROT), albumin (ALB), urea, insulin (INS), T3, T4, and cortisol (CORT), and the RQUICKIBHB index of insulin resistance was calculated. Cows milked 3X in NEB represent a special cluster that partially overlaps with cows milked 2X in NEB and has no contact points with cows in PEB. Cows milked 3X had higher levels of NEFA, BHB, AST, GGT, TBIL, and CORT and lower levels of GLU, Ca, INS, and T4. Cows milked 3X in NEB had higher levels of NEFA, BHB, AST, GGT, TBIL, and CORT and lower levels of GLU, CHOL, TGC, TPROT, P, INS, RQUICKIBHB, and T3 compared with cows milked 2X in NEB and cows in PEB. In cows milked 3X, lipolysis and ketogenesis were much more prominent, and EB levels were lower, implying a pronounced shift in homeorhesis. Metabolic and endocrinology parameters were determined mainly by the values of EB, NEFA, and BHB in cows milked 3X in NEB compared with other categories of cows. The results confirm the peculiarity of metabolic adaptation in cows with increased MF, characterized not only by differences in the concentration of metabolites but also in their interactions.

6 December 2021 in Parasite
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Journal Article
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JJJožica Ježek
Jožica Ježek
KMKarmen Mirtič
Karmen Mirtič
NRNina Rešetič
Nina Rešetič
JHJaka Jakob Hodnik
Jaka Jakob Hodnik
ARAleksandra Vergles Rataj
Aleksandra Vergles Rataj
The aim of this study was to evaluate the effect of feed additives (pumpkin seed cake and cloves) on the egg excretion of gastrointestinal nematodes (GIN) in sheep. Thirty ewes naturally infected with GIN were randomly selected from a flock and assigned to the following groups of 10 animals each: clove group (received 1.8 g ground cloves/ewe/day, for 7 days), pumpkin seed cake group (200 g pumpkin seed cake/ewe/day, for 7 days) and control group. Before starting the study, on day 0, and 5 days after the 7-day supplementation, on day 12, the body condition and FAMACHA scores were assessed and individual faecal egg counts (FEC) were performed. The mean body condition and the FAMACHA scores did not change significantly between day 0 and 12 with the exception of a significantly deteriorated FAMACHA score in the clove group. The percentage reduction of FEC was 40.7% on day 12 in the clove group and 52.9% in the pumpkin seed cake group. In the control group, FEC increased by 8.7%. A coproculture of faecal samples from four of the most infected animals on day 0 revealedTrichostrongylusspp. larvae L3 in all four selected ewes,Ostertagiaspp. andCooperiaspp. in three andHaemonchus contortusin one ewe. These results are promising and encourage further studies aimed to evaluate the possibility that these plant supplements could be a complementary method for parasite control, thus reducing the need for chemotherapy.

12 June 2024 in Animals
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Journal Article
Open access
DKDražen Kovačević
Dražen Kovačević
Marko CincovićMarko Cincović
Marko Cincović
MMMira Majkic
Mira Majkic
JSJovan Spasojević
Jovan Spasojević
RDRadojica Djokovic
Radojica Djokovic
JJJožica Ježek
Jožica Ježek
Hemolysis is a common cause of errors in laboratory tests as it affects blood parameters and leads to a positive or negative bias. This study aims to examine the relationship between the level of hemolysis (expressed as cell-free hemoglobin concentration, g/L) and the variability of metabolic and endocrine parameters and to determine the threshold level of hemolysis that causes an analytically and clinically significant bias for the twenty most frequently examined blood parameters in cows. Paired blood samples of 10 mL each were obtained from 30 cows. One was subjected to mechanical trauma and plasma was extracted directly from the other. Hemolyzed and non-hemolyzed samples from the same animal were mixed to obtain final samples with cell-free hemoglobin concentrations of 0, 1, 2, 4, 6, 8, and 10 g/L. Metabolic and endocrine parameters were measured in the samples and their deviation and the linear equation between the level of hemolysis and the deviation were determined. The following threshold values of hemolysis were determined, which correspond to the acceptable analytical (lower value) and clinical (upper value) levels of parameter variability: BHB 0.96 and 4.81; NEFA 0.39 and 3.31; GLU 0.38 and 3.90; ALB 1.12 and 6.11; TPROT 1.40 and 6.80; UREA 6.62 and 20.1; TBIL 0.75 and 5.65; AST 0.11 and 2.18; GGT 1.71 and 8.90, LDH 0.01 and 0.11, ALP 0.97 and 2.95; TGC 1.56 and 15.5; CHOL 1.29 and 8.56; Ca 5.68 and 25.7; P 0.57 and 8.43; Mg 1.10 and 8.47; INS 1.15 and 3.89; T3 8.19 and 15.6; T4 8.97 and 18.5; and CORT 2.78 and 11.22 g/L cell-free hemoglobin. Three decision levels are available for each metabolic and endocrine parameter: if hemolysis is below the lower (analytical) threshold value, results can be reported without restriction; if hemolysis is between the lower and upper thresholds, the results can be issued with guidance in the form of corrective linear equations; and if hemolysis is above the upper (clinical) threshold, the results and sample must be discarded. This method contributes to an optimal approach to hemolysis interference with metabolic profile parameters in blood samples from cows.

16 April 2021 in Spanish Journal of Agricultural Research
Verified
Journal Article
Closed access
RRRenata Relic
Renata Relic
NLNada Lakic
Nada Lakic
LJLjiljana Jankovic
Ljiljana Jankovic
VDVesna Davidovic
Vesna Davidovic
Jože StaričJože Starič
Jože Starič
JJJožica Ježek
Jožica Ježek
Aim of the study: Calf rearing practices vary in different countries and may be affected by many factors. Poor management is related to diseases outbreak and death in calves. This study aimed to analyze practices in calf rearing and the occurrence of common calf diseases on family farms in two European countries and to examine the characteristics of a farmer and his farm as factors that may affect the way of performing practices related to calves’ health.Area of study: Slovenia and Serbia.Material and methods: For collecting data, the same questionnaire-based survey was distributed among cattle farm owners in Slovenia and Serbia.Main results: The following factors showed a significant influence (p<0.05) on certain rearing practices: farm size (on time for checking calves, milk reheating, and providing rehydration fluids to the calf with diarrhea in Slovenia), specialization of the production (on preventive antiparasitic treatments and restriction of drinking water for calves with diarrhea in Slovenia, and the time for checking calves in Serbia), breeder’s age (on colostrum quality checking in Slovenia), and breeder’s education (on time for checking calves and checking colostrum quality in Serbia). The results pointed out the rearing practices to be improved in both countries, Slovenia and Serbia, such as colostrum management and prevention strategies of calf diseases.Research highlights: Characteristics of the farmer and his farm may affect many aspects of calves’ rearing. Continuous education of farmers and appropriate production planning can contribute to better farm productivity and better health and welfare of calves.