Introduction: Heat stress negatively affects both animal reproductive performance and their overall wellbeing and welfare. When temperatures soar, the body responds to maintain balance, resulting in heat stress. This triggers various responses, including the buildup of reactive oxygen species (ROS), which can harm sperm vitality through lipid peroxidation. Oxidative damage can result in sperm dysfunction. This study aimed to evaluate the effects of environmental heat stress on canine quantitative and qualitative ejaculate parameters.Methods: Thirty-six male crossbred dogs were involved in the trial. This study was performed in 2022, precisely from May to August. Dogs were subdivided in two groups, one heat stressed (HS) and one in thermoneutrality (TN). Thermo Hygrometric Index (THI) was hourly measured and ranged from 60 to 71 in TN dogs and from 60 to 83 for HS dogs. Semen and blood samples were collected at 30-day intervals, starting from May (0 days), and then at 30 days, 60 days, and 90 days and analysis for evaluating biochemical profile, semen oxidative status, and semen quality were performed.Results: In HS dogs, serum total protein, albumin, and urea concentrations showed a significant decrease after 60 days (P < 0.01), with values lower than those observed in TN dogs (P < 0.01). Both catalase and glutathione peroxidase concentrations were reduced after 60 days in HS dogs, showing lower levels than the TN group (P < 0.01 and P < 0.05, respectively). Antioxidant potential increased over time in HS dogs, reaching higher values at 60 days (P < 0.05) and 90 days (P < 0.01). On the other hand, ROS in the sperm of HS animals rose by day 90, surpassing the values recorded at previous time points and in TN dogs (P < 0.01). Semen concentration (P > 0.01) and total sperm count (P < 0.05) declined after 30 days in the HS group and remained lower than the TN group throughout the trial.Discussion: The study demonstrates that heat stress negatively affects the oxidative status and sperm quality of male dogs, reducing reproductive performance. However, further research is needed due to the lack of complete breed homogeneity in the study groups.

In small and laboratory animals epididymal spermatozoa can be collected only by the mincing technique however, blood and cell debris contamination may adversely affect the quality of the samples. This study aimed at performing the retrograde flushing technique, for the first time, in the tomcat. In the first experiment attempts to insert a blunted needle into tomcats' ductus deferentes were made and the cannulation time and the success rate were recorded. In the second experiment, insertion of the needle into the ductus was carried out under a stereomicroscope for one testis, while the other was submitted to mincing for sperm recovery and the samples obtained from paired testes were compared. In the first study, only twenty-eight percent of the cannulation attempts were successful whereas in the second experiment, 91% of the deferentes were successfully cannulated: 80% of the ducts were cannulated in less than three minutes. The stereomicroscope-aided retrograde flushing samples showed significantly higher sperm viability, motility and velocities, as compared to those resulted from mincing. The domestic cat serves as a model for more than 36 species of wild felids; the developed stereomicroscope-aided retrograde flushing technique has the potential to become the gold standard method for harvesting spermatozoa of endangered species that have a small ductus deferens.

Repeat breeder (RB) cows are clinically healthy animals with regular oestrous cycles that do not become pregnant after three or more services. This syndrome has an incidence ranging between 10.1% and 24%. Repeat breeder syndrome (RBS) in dairy cows leads to economic losses to dairy farmers by increasing the calving interval and consequently reducing milk and calf production. RBS has a complex oetiopathogenesis as many factors are involved in its onset. The causes can be grouped into two categories: causes leading to fertilisation failure and factors leading to early embryonic death. Accurate identification of the cause and early diagnosis of RBS is essential to minimise the problems that this issue brings to the farm, but is not always possible. Hypothesising the underlying aetiology of the syndrome is also crucial for targeted therapy, whether pharmacological or managerial. The aim of this review is to report the different therapies, proposed in the literature, for the treatment of RBS in cattle, based on the knowledge of possible aetiological causes.

Introduction: Heat stress negatively affects canine reproductive health by inducing oxidative stress and impairing sperm quality. This study assessed the efficacy of a polyphenolic extract from Loblolly pine (Pinus taeda) lignin (PTHL), in mitigating heat stress-induced oxidative damage and preserving sperm quality in dogs.Methods: Forty clinically healthy male dogs were divided into two groups: a control (CON) group receiving a standard diet and a PTHL-supplemented group for 90 days. During summer, dogs were exposed to natural heat stress, and key parameters, including serum biochemical markers, oxidative stress indicators, antioxidant enzyme activity, and sperm quality were evaluated. Mixed-effects models analyzed group, time, and interaction effects.Results and discussion: PTHL supplementation significantly reduced plasma TBARS and seminal d-ROMs levels (P < 0.01), indicating lower lipid peroxidation and confirming its protective effects. Antioxidant capacity improved in the PTHL group, with increased activities of antioxidant enzyme activity (SOD, CAT, and GSPx) and elevated plasma Ferric Reducing Antioxidant Power (FRAP) levels (P < 0.01). Notably, the PTHL group demonstrated higher progressive motility (P < 0.01) and a greater percentage of rapid-movement sperm (P < 0.01) at 90 days, indicating improved sperm function under heat stress.Conclusion: These findings suggest that PTHL enhances antioxidant defenses, mitigating heat stress-induced reproductive impairment. This natural strategy may improve fertility in dogs facing environmental challenges. Future studies should explore different dosages and extended supplementation to optimize its benefits.

The aim of the present study was to understand the involved factors in follicular cysts in dairy cows. The study consisted of an in vivo and in vitro approach. The in vivo part, hormonal evaluation (Kisspeptin‐10 [Kp‐10], Gonadotropin inhibiting hormone [GnIH], Luteinizing hormone [LH], Oestrogens [E₂] and cortisol) was performed in sera of both healthy (H) and cows with follicular cysts (FC). The in vitro part was concentrated on estimating the distribution of GPR54 (Kp‐10 receptor) and GPR147 (GnIH receptor) on cystic and preovulatory follicles. Serum concentrations of Kp‐10, GnIH, LH, E₂ and cortisol were significantly higher in Group FC compared with Group H. Gene expression analysis showed a reduction in GPR54 mRNA levels in FC compared to preovulatory follicles, while no expression of the GPR147 receptor was detected. The lower presence of GPR54 in FC compared to the preovulatory follicle can be determined by a down‐receptor regulation induced by elevated serum concentrations of Kp‐10 in cows with ovarian FC. Endocrine imbalances of the hypothalamic–pituitary–ovarian axis, characterising FC, may reflect altered patterns of Kp‐10 and GnIH secretion.

This study aimed to describe a technique to locate retained testes in pigs by means of ultrasound examination and thereafter proceed with cryptorchidectomy. Fifty-two monolateral cryptorchid pigs were enrolled. After anaesthesia, 42 pigs (Group U) underwent ultrasound examination before cryptorchidectomy, and 10 pigs (Group C) were used as control group without ultrasonography. The total duration of anaesthesia, ultrasound examination, and surgery was evaluated. In 10 pigs of Group U and 10 pigs of Group C, the heart rate (HR), respiratory rate (RR), and body temperature (T) were monitored to assess intraoperative pain response. An operator used the Piglet Grimace Scale (PGS) to assess postoperative pain. In Group U, the total time required for anaesthesia and surgery was less than Group C. No intra- or postoperative complications were reported in both groups. For HR, RR, and T, no statistically significant differences were observed. During the postoperative pain assessment, the highest pain scores were recorded at T6 (6 h after surgery). Ultrasound examination was found to be a valid technique for locating the retained testis in the abdomen in cryptorchid pigs and to reduce the duration of the surgery.