Nosema ceranae is the most widespread microsporidian species which infects the honey bees of Apis mellifera by causing the weakening of their colonies and a decline in their productive and reproductive capacities. The only registered product for its control is the antibiotic fumagillin; however, in the European Union, there is no formulation registered for use in beekeeping. Thymol (3-hydroxy-p-cymene) is a natural essential-oil ingredient derived from Thymus vulgaris, which has been used in Varroa control for decades. The aim of this study was to investigate the effect of thymol supplementation on the expression of immune-related genes and the parameters of oxidative stress and bee survival, as well as spore loads in bees infected with the microsporidian parasite N. ceranae. The results reveal mostly positive effects of thymol on health (increasing levels of immune-related genes and values of oxidative stress parameters, and decreasing Nosema spore loads) when applied to Nosema-infected bees. Moreover, supplementation with thymol did not induce negative effects in Nosema-infected bees. However, our results indicate that in Nosema-free bees, thymol itself could cause certain disorders (affecting bee survival, decreasing oxidative capacity, and downregulation of some immune-related gene expressions), showing that one should be careful with preventive, uncontrolled, and excessive use of thymol. Thus, further research is needed to reveal the effect of this phytogenic supplement on the immunity of uninfected bees.

To improve the genomic evaluation of milk-related traits in Holstein-Friesian (HF) cattle it is essential to identify the associated candidate genes. Novel SNP-based analyses, such as the genetic mapping of inherited diseases, GWAS, and genomic selection, have led to a new era of research. The aim of this study was to analyze the association of each individual SNP in Serbian HF cattle with milk production traits and inbreeding levels. The SNP 60 K chip Axiom Bovine BovMDv3 was deployed for the genotyping of 334 HF cows. The obtained genomic results, together with the collected phenotypic data, were used for a GWAS. Moreover, the identification of ROH segments was performed and served for inbreeding coefficient evaluation and ROH island detection. Using a GWAS, a polymorphism, rs110619097 (located in the intron of the CTNNA3 gene), was detected to be significantly (p < 0.01) associated with the milk protein concentration in the first lactation (adjusted to 305 days). The average genomic inbreeding value (F_ROH) was 0.079. ROH islands were discovered in proximity to genes associated with milk production traits and genomic regions under selection pressure for other economically important traits of dairy cattle. The findings of this pilot study provide useful information for a better understanding of the genetic architecture of milk production traits in Serbian HF dairy cows and can be used to improve lactation performances in Serbian HF cattle breeding programs.

This study investigates the impact of nutritional supplementation on semen quality, epigenetic-related gene expression, and oxidative status in boars. Thirty boars were divided into a control group and a treatment group receiving Espermaplus (a supplement containing various vitamins, amino acids, omega-3 fatty acids, and trace elements with antioxidant properties). The experiment was performed for 12 weeks. Semen samples were collected at four moments: before starting the supplementation and after 3 weeks, 8 weeks, and 12 weeks. Spermatozoa concentration, motility, and kinematics were assessed using the CASA system. The measured parameters included curvilinear velocity—VCL; straight-line velocity—VSL; average path velocity—VAP; curvilinear distance—DCL; straight line distance—DSL; distance of average path—DAP; amplitude of lateral head displacement—ALH; beat-cross frequency—BCF; and head activity—HAC. Moreover, superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity in seminal plasma, as well as the concentration of thiobarbituric acid reactive substances (TBARS), were measured to assess oxidative stress levels in boar’s seminal plasma. The expression of epigenetic-related genes such as Protamine 1 (Prm1), Protamine 2 (Prm2), and DNA-methyltransferase 3 alpha (Dnmt3a) were evaluated using real-time PCR. The treated group showed a significant increase in spermatozoa concentration (p = 0.003), total motility (p = 0.001), and progressive motility (p = 0.002) after 12 weeks compared to the control group. Kinematic parameters such as VCL, VSL, and VAP were also significantly higher (p < 0.001; p = 0.028; p < 0.001, respectively) in the treated group by the end of the experiment. SOD and GPx activities were consistently higher (p < 0.01; p < 0.001, respectively) in the treated group, indicating enhanced antioxidative capacity. TBARS levels as an indicator of lipid peroxidation and oxidative damage were significantly lower (p < 0.01) in the treated group by the end of the study. Significant changes were observed in the expression of epigenetic-related genes. The supplementation of boar diets with Espermaplus significantly improved semen quality, reduced oxidative stress, and had an impact on the expression levels of certain epigenetic-related genes, suggesting that dietary antioxidants and bioactive compounds can enhance boar semen.

Depending on intensity, physical exercise in horses causes various changes in the parameters of hematological, biochemical, acid-base, and electrolyte status, which can affect the health and athletic performance of the horse. This study?s objective was to look at how submaximal exercise at the end of the racing season affected the horses? hematological, biochemical, acid-base, and electrolyte status markers. In this study, eight (n=8) trotters, aged 4?2 years, were involved. Venous blood samples were drawn from each horse by jugular puncture before and after exercise to determine hematologic, biochemical, acid-base and electrolyte parameters. The submaximal physical exercise in this study was two intervals of 2,000 m of slow trotting and two consecutive runs of 500 m at submaximal level. Hematocrit (HCT), red blood cell (RBC) and monocyte count, hemoglobin (HGB) concentration, aspartate aminotransferase (AST) activity, and glucose concentration increased significantly after the exercise. Additionally, significant decreases in venous blood pH, bicarbonate (HCO3-) and total CO2 (TCO2) concentration, base excess of the extracellular fluid (BEecf), and ionized Ca2+ (iCa2+) concentrations were established after exercise. In contrast, partial pressure of CO2 (pCO2), total concentration of weak acids (Atot), the anion gap (AG), and total protein and lactate concentrations were significantly higher after exercise. Considering the significant changes in the parameters of hematological, biochemical, and acid-base status after submaximal exercise, determining those parameters would be useful for monitoring the health and performance of trotters.

Given the influence of retentio secundinarum (RS) on the reproductive performance of cows, the current work aimed to assess the effect of various approaches to the treatment of retained placenta on the main reproductive parameters, primarily on the interval from parturition to the first service, and the insemination index. The trial involved 120 dairy cows in which the placenta was not expelled within 24 h postpartum. The first group (G1, n=60) contained cows in which the retained placenta was not extirpated, but they were administered antibiotics. The second group (G2, n=60) comprised cows in which the placenta was removed manually, and were also administered antibiotics. At the end of the study, 53 cows remained in G1 and 54 cows in G2. According to medicament therapy, both groups were divided into three sub-groups treated with: procaine benzylpenicillin, chlortetracycline hydrochloride or ceftiofur. Comparison of the performance of G1 and G2 cows showed significantly better fertility parameters occurred in the animals from which the retained placenta was extracted manually. The pregnancy rate in the G2 group was remarkably higher than in the G1 group. The average service interval was significantly lower (p<0.05) in the G2 group compared to the G1 group. The best results were obtained with the i.m. administration of ceftiofur after the removal of the placenta.

The reproductive efficiency of the cows was monitored after two resynchronization protocols: Ovsynch (OVS) and Double Ovsynch (DOS). The research initially included 70 HF cows who entered the first synchronization protocol – Presynch. Cows that did not conceive after the first synchronization were divided into two groups and introduced to two resynchronization protocols. In the first group of cows (n=35), the DOS protocol began with the application of GnRH on day 22 after the Presynch TAI (Timed Artificial Insemination), and seven days later pregnancy check-up was done and PGF _2α was applied only to non-pregnant cows (n=23), which remained in the study. In the second group of cows, the OVS protocol started on day 32 after Presynch TAI only in non-pregnant animals (n=20). Progesterone (P4) concentration was determined at the time of application of GnRH1, PGF _2α and GnRH2 in both groups of cows, and then 30 days after Resynch TAI, ultrasound pregnancy diagnosis was done. A higher percentage of pregnant cows were recorded in the OVS group compared to the DOS group (45% and 35%, respectively). The concentration of P4 in the serum of cows in the DOS group during the first measurement (GnRH1) was significantly higher than the value in cows that did not conceive (p<0.05), while in the third measurement (GnRH2) the average concentration of P4 in conceiving cows was significantly lower (p<0.001) compared to cows that did not coincive. The open days period was significantly longer in pregnant cows that were resynchronized using the DOS protocol compared to cows from the OVS protocol. In conclusion, the OVS protocol of estrus resynchronization in dairy cows proved to be more successful than the DOS protocol. However, considering the advantages the OVS, it is needed to determine which day of the sexual cycle is the best to start resynchronization.