Animal Welfare Assessment Protocols for Bulls in Artificial Insemination Centers: Requirements, Principles, and Criteria

Antimicrobial susceptibility rates in gram-positive catalase-negative cocci from sheep and goat genital microbiota

Gram-positive catalase-negative cocci (GPCNCs) are significant components of the genital microbiota in sheep and goats. However, characterizing them can be difficult due to overlapping culture features and the limited information on their susceptibility to antibiotics. In this study, 97 foreskin and 13 vaginal swabs were investigated using a culturomic approach. Of 110 animals, 76 (69.09 %) hosted GPCNCs, including strains from Streptococcaceae (37, 33.64 %), Aerococcaceae (30, 27.27 %), Enterococcaceae (6, 5.45 %) and other minor species. With increasing antimicrobial resistance rates in livestock, surveillance programs are globally required, so we conducted a pilot study on GPCNCs isolated from the genital mucosa surfaces of sheep and goats using the minimal inhibitory concentration assay (MIC). Due to gaps in interpretative standard breakpoints, normalized resistance interpretation was used for setting epidemiological susceptibility cut-off values (COWTs). Of 57 suitable strains, the majority (80.71 %) showed high COWTs with decrease susceptibility to at least one antimicrobial class, with 22.81 % displaying multiresistant profiles. Of interest, combined resistances to beta-lactams, macrolides, lincosamides, and tetracyclines were detected in strains of Streptococcus plurianimalium. Further combinations, including resistance to beta-lactams, pleuromutilins, aminoglycosides, and lincosamides, were also recorded in both Streptococcus uberis and Enterococcus spp. strains. Being beta-lactams, macrolides, and tetracyclines the most used antibiotics in livestock worldwide, our results highlight the need for their prudent use. Collectively, our findings highlight that small ruminant genital microbiota can serve as reservoirs for opportunistic severe pathogens, often zoonotic, carrying multidrug resistances, thus standing for high risks for both animals and humans.

The effect of different concentrations of taxifolin on the quality of frozen and thawed semen of Simmental cattle

Background

Artificial insemination (AI) is one of the most important reproductive technologies used to modify animals genetically. Using this method, the genetic composition of the herd can be improved and selected by choosing bulls with excellent genetic characteristics. Taxifolin (TXF), a plant flavonoid, has shown an antioxidative effect.

Aims

The current study aimed to evaluate the impact of TXF on the quality of frozen-thawed semen in Fleckvieh (Simmental) dual-purpose bulls.

Methods

Freezable semen specimens were obtained by an artificial vagina. Ejaculates were equally divided into six parts for six experimental groups, including without adding TXF to diluent (C), adding 25 (T25), 50 (T50), 100 (T100), 200 (T200), and 400 (T400) μM TXF. Sperms were frozen in a one-step dilution method. Semen factors, including motility, viability, sperm membrane integrity, DNA damage, and oxidant and antioxidant enzyme activities, were examined after thawing.

Results

Our findings revealed that all semen quality parameters, antioxidant enzyme activities, and free radical levels were superior in TXF-treated groups compared to the control group, and the differences were noticeably higher in the T100 group than the other groups.

Conclusion

Adding 100 μM TXF to diluent could improve the quality of bull frozen semen.