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Bovine mastitis is a highly prevalent disease that causes significant economic losses to dairy farmers through the discarding of milk and the use of antibiotics. Streptococcus uberis is a major causative pathogen of bovine mastitis, but the roles of its virulence genes in pathogenicity are not fully understood. This study investigated the association between the presence of six virulence genes in S. uberis isolated from naturally occurring cases of clinical mastitis and the duration of mastitis treatment. The prevalence of each virulence gene among Japanese isolates was as follows: sua 92.6%, hasA 81.9%, oppF 98.9%, pauA 93.6%, gapC 100%, and cfu 5.3%. Nine virulence gene profiles were identified among Japanese isolates, and a significant association between these profiles and treatment duration was observed. The presence or absence of individual virulence genes was not associated with treatment duration. Amino acid sequence variation was observed in sua, hasA, and pauA. When strains were analyzed by amino acid sequence variant, treatment duration for sua variant 1 was significantly longer than that for strains lacking the sua gene. In this study, sua, hasA, oppF, pauA, and gapC were detected at high rates, indicating that these genes are involved in the development of clinical mastitis. The findings suggest that the pathogenicity of S. uberis varies with virulence gene profile. Furthermore, amino acid sequence variation within sua may modulate its contribution to pathogenicity. However, since the sequences analyzed in this study were partial sequences of each virulence gene, with the exception of pauA, full-length sequence analysis will be required for a more complete characterization of the pathogenesis of S. uberis in clinical mastitis.

To enhance the immunogenicity of the Pseudomonas aeruginosa oprI gene recombinant subunit vaccine, polysaccharides (PS) extracted from Cornus officinalis were used as an adjuvant to prepare a polysaccharide-adjuvanted recombinant subunit vaccine (PS-rOprI). Immune responses and protective efficacy in BALB/c mice were evaluated and compared with those of a white oil adjuvant recombinant subunit vaccine (WO-rOprI) and an inactivated vaccine. Results showed that PS-rOprI induced bacteria-specific antibody levels comparable to WO-rOprI, although its IgG1 and IgG2a concentrations were lower. Moreover, its IgG1/IgG2a ratio and serum IL-4 concentration were significantly higher than those in the WO-rOprI and inactivated vaccine groups (P<0.05), while the ratio of T-bet to GATA-3 transcription levels in splenic lymphocytes was significantly lower than in the WO-rOprI and inactivated vaccine groups (P<0.05), suggesting that Cornus officinalis polysaccharides skew the immune response toward Th2. However, Th1-type immune indicators such as serum IFN-γ and IL-2 levels, as well as T-bet transcription levels in splenic lymphocytes, were lower in the PS-rOprI group. In antigen-specific splenic lymphocyte proliferation assays, the PS-rOprI group showed no significant difference in stimulation index (SI) compared to the inactivated vaccine group. However, it was significantly lower than the WO-rOprI group (P<0.05), indicating limited cellular immune enhancement by this adjuvant. Challenge protection tests showed that the inactivated vaccine, PS-rOprI, and WO-rOprI provided protection rates of 96%, 64%, and 52% for mice, respectively. In summary, Cornus officinalis polysaccharide can serve as a Th2-skewing immune adjuvant for the oprI gene recombinant subunit vaccine. Although the enhancement of cellular immunity was relatively weak, this study provides a valuable reference for novel Pseudomonas aeruginosa vaccine development and adjuvant screening for recombinant subunit vaccines.

This study evaluated whether gonadotropin preparation composition influences ovarian response and in vitro embryo production (IVEP) when a simplified single-dose superstimulation protocol is used before ovum pick-up (OPU). Thirty-six Holstein heifers were randomly allocated to three groups (n = 12). After dominant follicle removal (DFR), FSH-STI received a single intramuscular injection of 5 mL Stimufol® (250 µg pFSH and 50 µg pLH) 24 h later, FSH-FOL received a single intramuscular injection of 10 mL Folltropin®-V (200 mg NIH-FSH-P1), and FSH-NO received no gonadotropin. OPU was performed 72 h after DFR in all groups. The number of 3-8 mm follicles and COCs recovered per OPU was greater in both superstimulated groups than in FSH-NO (p < 0.05), with no difference between FSH-STI and FSH-FOL. The proportion of morphologically viable COCs was 83.22%, 86.55%, and 68.48% in FSH-STI, FSH-FOL, and FSH-NO, respectively (p < 0.05), and the overall distribution of COC quality grades differed among groups (p < 0.05). Blastocysts per OPU were highest in FSH-FOL (3.25 ± 1.05), followed by FSH-STI (2.41 ± 0.90) and FSH-NO (1.33 ± 0.49) (p < 0.05). However, cleavage and blastocyst rates calculated per viable COC did not differ among groups (p > 0.05). Thus, both gonadotropin preparations increased oocyte yield, while FSH-FOL yielded the highest number of blastocysts per OPU. These findings suggest that the composition of the gonadotropin preparation, including its LH content, may influence the outcome of OPU/IVEP.

In this study, the effect of adding progesterone (PRID) to the presynchronization (G6G/Ovsynch) protocol on first insemination pregnancy rates in cows and heifers was investigated. Holstein cows (n:181) and heifers (n:100) were used in the study and divided into four groups as follows: Cow G6G (cow control group, n:79), Cow G6G/PRID (cow treatment group, n:102), Heifer G6G (heifer control group, n:50), and Heifer G6G/PRID (heifer treatment group, n:50). The animals in the treatment groups were subjected to the G6G/PRID protocol; namely, the G6G/Ovsynch protocol together with intravaginal progesteron administration between days 8-15 of the protocol. Pregnancy examinations were performed between days 30–35 after AI. When First insemination pregnancy rates obtained after AI were evaluated, it was determined that pregnancy rates in cows were 56.96% in the control group and 51.96% in the treatment group, in heifers were 64% in the control group and 68% in the treatment group, and there was no statistical difference between the groups (p>0.05). When pregnancy rates at first insemination were evaluated in primiparous and multiparous cows, it was found that multiparous cows had numerically higher pregnancy rates compared to primiparous cows in both the control and study groups. When pregnancy rates at first insemination were evaluated in cyclic and non-cyclic animals in cows and heifers, it was found that cyclic cows and heifers had numerically higher pregnancy rates in the study group, while non-cyclic cows and heifers had numerically higher pregnancy rates in the control group. According to the obtained results, it was determined that adding progesterone to the G6G protocol in cows did not have a positive effect on pregnancy rates. The pregnancy rates obtained in heifers using the G6G protocol were quite good, and based on the data obtained, it was concluded that successful results can be achieved in heifers using modified presynchronization method.

This study investigated the dynamics of maternal humoral immunity in Hisex laying hens subjected to prolonged Newcastle disease (ND) vaccination by evaluating IgM, IgG, and IgA concentrations in egg yolk and egg white. Hens aged 28, 31, 37, and 61 weeks were examined, and antibody levels were quantified using commercially available ELISA kits at four time points, days 3, 7, 10, and 14, within collection period. IgM responses were most pronounced in younger hens (28 and 31 weeks), which exhibited early peaks (p≤0.05) followed by significant declines (p≤0.05), consistent with the transient nature of primary antibody responses. Older hens (37 and 61 weeks) showed attenuated or delayed IgM activity, and egg‑white IgM declined progressively with age, suggesting reduced early‑phase immune responsiveness. IgG was predominantly yolk‑associated. In 28‑ and 31‑week‑old hens, yolk IgG remained high and stable; egg‑white IgG showed a day‑10 decrease in 31‑week‑old hens (p < 0.001). In 61‑week‑old hens, yolk IgG increased at day 10 (p < 0.01) but decreased by day 14 (p < 0.05). IgA showed early increases but declined sharply by days 10 and 14 in most age groups (p < 0.05). These reductions were most pronounced in older hens, indicating that mucosal immune responses were short‑lived and more susceptible to age‑related decline. Overall, prolonged ND vaccination effectively supported long‑term IgG‑mediated maternal immunity but was less successful in sustaining IgM and IgA levels, particularly in older hens. These findings highlight significant age‑dependent differences in maternal antibody deposition and underscore the importance of optimizing vaccination programs to enhance protection in newly hatched chick.