Reproduction in Domestic Animals最新文献

During the in vitro maturation process of oocytes, oxidative stress is commonly present, and excessive oxidative stress can affect oocyte maturation. Thus, adding antioxidants during maturation is an effective strategy for reducing oxidative stress. N-acetylcysteine (NAC), a derivative of cysteine, participates in glutathione (GSH) metabolism and stimulates glutathione synthesis. However, a clear understanding of the effect of NAC on sheep oocytes remains unknown. In this study, we investigated NAC's impact on the maturation of sheep oocytes, and the results revealed that the maturation rate, and subsequently the cleavage and blastocyst formation, were significantly enhanced by incubation with 1 mM NAC. The GSH and Ca²⁺ levels increased, and the cortical granules were significantly elevated, whereas the reactive oxygen species levels were significantly reduced in the 1 mM NAC-treated group. Additionally, the number of inner cell masses was significantly increased. The findings of this study support the hypothesis that NAC increases oocyte maturation rate by protecting them from oxidative stress damage. These discoveries provide a new approach for improving the efficiency of in vitro production of sheep embryos.

This study evaluated the clinical efficacy of aglepristone for the management of canine pyometra-either as a sole therapy or in combination with different antibiotic regimens-and investigated the association between aglepristone dosing and the occurrence of vaginal hyperplasia during the subsequent estrous cycle. Eighty-seven intact bitches diagnosed with pyometra were enrolled and divided into two experiments. In Experiment I, 57 bitches were randomly assigned to three treatment groups (n = 19/group): (1) AGL, aglepristone alone; (2) AGL-CEF, aglepristone plus ceftriaxone; and (3) AGL-CEF-MET, aglepristone plus ceftriaxone and metronidazole. Clinical examinations and haematological and biochemical profiles were assessed every 48 h for 15 days. In Experiment II, 30 bitches were treated with aglepristone using two protocols: AGL 4X (10 mg/kg s.c. on Days 0, 1, 8 and 15) or AGL 2X (10 mg/kg s.c. on Days 0 and 1). Incidence and severity of vaginal hyperplasia, as well as post-treatment reproductive performance, were evaluated during the subsequent oestrus. All three treatment protocols achieved clinical resolution of pyometra-including the aglepristone-only group-with normalisation of leukocyte counts and serum biochemical markers. In Experiment II, vaginal hyperplasia occurred in 53.3% of bitches in the AGL 4X group versus 7% in the AGL 2X group. Grade III hyperplasia was associated with pyometra recurrence and reduced pregnancy rates. Overall pregnancy rate in Experiment II was 80%. These findings indicate that aglepristone is an effective, fertility-preserving treatment for canine pyometra, even when administered without systemic antibiotics. However, high-dose or prolonged administration may induce oestrogen-mediated adverse effects such as vaginal hyperplasia and disease recurrence. A reduced dosing regimen appears safer while maintaining equivalent clinical and reproductive efficacy.

Cryopreservation of ram sperm is a cornerstone in reproductive biotechnology but is often accompanied by oxidative damage that compromises post-thaw sperm quality. Curcumin, a natural polyphenol with potent antioxidant properties, may offer protection against cryo-induced injuries. This study evaluated the effects of curcumin supplementation at two concentrations (10% and 20%) in semen extenders on the functional and molecular characteristics of ram spermatozoa. A total of 14 ejaculates were collected from healthy adult rams and randomly allocated into three groups: control (no curcumin), C1 (10% curcumin) and C2 (20% curcumin). Semen samples were cryopreserved using a Tris-based extender, and post-thaw evaluations included total motility, viability (eosin-nigrosin), morphology (head, midpiece, tail abnormalities), membrane integrity (HOST), chromatin integrity (toluidine blue) and PRDX5 gene expression via qPCR. Curcumin supplementation, particularly in the C2 group, significantly improved total motility and viability (p < 0.01), while reducing head and tail morphological abnormalities and chromatin damage (p < 0.05), compared to the control. No significant difference was observed in PRDX5 gene expression among groups (p > 0.05). These improvements are likely attributed to curcumin's antioxidant activity, including ROS scavenging and membrane stabilisation. Curcumin supplementation in semen extenders enhances post-thaw sperm quality in rams by improving functional parameters and maintaining chromatin integrity, without modulating PRDX5 gene expression. These findings support the potential of curcumin as a safe and effective cryoprotective additive in ovine artificial insemination and genetic conservation protocols. Further research combining transcriptomic and proteomic analyses (or approaches), along with validation of post-thaw sperm fertility, is needed to clarify curcumin's effects and its potential in livestock breeding.

This experiment evaluated the effects of increasing MitoQ concentrations in semen extender on post-thaw quality of Holstein bull sperm, including motility, membrane integrity, antioxidant status and viability. Semen samples were collected, pooled and diluted with extender containing 0 (control), 5, 50, 500 and 1000 nM of MitoQ and frozen through the standard procedure. An increase in MitoQ supplementation positively influenced total and progressive motility, as well as average path velocity; however, these effects were not statistically significant until the concentration reached 50 nM. The highest MitoQ level (1000 nM) showed no difference from the control group. Supplementation of semen extender with 50 and 500 nM of MitoQ significantly increased sperm membrane integrity and mitochondrial activity. Sperm viability improved significantly in concentrations of 5, 50 and 500 nM of MitoQ compared to control, whereas 1000 nM of MitoQ did not show any difference from the control group. Moreover, MitoQ significantly reduced MDA level regardless of its concentration. The concentrations of 50 and 500 nM of MitoQ significantly reduced ROS concentration. It can be concluded that 50 and 500 nM of MitoQ in extender can improve sperm quality parameters in bull semen.

Dystocia due to developmental disorders causing foetal malformation is a significant challenge in bovine obstetrics, often resulting in severe birth complications. This narrative review provides an updated overview of the most common congenital syndromes associated with dystocia in cattle, emphasising both their clinical implications and underlying causes. Congenital disorders such as schistosoma reflexum, perosomus elumbis, arthrogryposis, hydrocephalus, anasarca and embryonic duplication are reviewed in detail, along with their impact on the course of calving. While the management of dystocia due to foetal malformations has remained relatively constant over time-mainly involving assisted delivery, foetotomy or caesarean section-our understanding of their aetiologies has advanced considerably. In addition to environmental factors, such as viral infections during gestation, genetic causes may also be implicated. Genetic aetiologies, including dominant de novo mutations and recessively inherited alleles, such as single nucleotide variants, larger structural variants or aneuploidies, have been identified as the cause of some of these congenital defects. This review provides a comprehensive resource on dystocia due to developmental disorders, offering veterinarians updated knowledge to guide clinical decision making and improve outcomes for both the dam and the calf.

Leptospirosis is a zoonotic disease caused by pathogenic bacteria of the genus Leptospira. A lesser-known form, equine genital leptospirosis (EGL), has been identified as a chronic and often silent infection involving the colonisation of the mare's genital tract. Despite its potential impact, EGL remains underdiagnosed and poorly understood, particularly in its association with reproductive inefficiency. This study showed the presence of Leptospira spp. DNA by lipL32-PCR in the genital tract of mares with a history of reproductive disturbances. Cervicovaginal mucus samples were collected from 120 adult mares exhibiting recent reproductive problems. Results showed that 30 (25%) of the mares tested positive for Leptospira DNA. Among these 30 positive cases, 23.3% had experienced abortions, 3.3% had stillbirths, 53.3% showed placental alterations, and 36.6% were subfertile. These findings suggest a possible association between EGL and reproductive disorders in mares. The high detection rate of Leptospira DNA in genital samples reinforces the need for increased awareness and improved diagnostic efforts.

Arbutin is a naturally present antioxidant derived from plants. The objective of this study was to examine the effect of arbutin on boar sperm during storage at 17°C and the underlying mechanisms. Our results showed that the addition of arbutin to extenders markedly enhanced the sperm (progressive) motility and plasma membrane and acrosomal integrity on Days 9 and 13 of preservation (p < 0.05), with the most pronounced effect of arbutin at the concentration of 100 μmol/L. The addition of 100 μmol/L arbutin also reduced the level of ROS and elevated the levels of ATP and MMP in boar sperm on Days 9 and 13 of preservation (p < 0.05). The subsequent sperm oxidative damage experiment showed that the addition of 100 μmol/L arbutin significantly alleviated the decrease in sperm (progressive) motility and in plasma membrane and acrosomal integrity caused by H₂O₂ (p < 0.05), whereas increased the T-AOC content and the activities of CAT and GPx antioxidant enzymes after 2 h of incubation at 37°C (p < 0.05). Further, the metabolomic analysis revealed that the addition of arbutin principally influenced lipid metabolism, and the Western blot analysis demonstrated that arbutin increased the sperm quality and the antioxidant capacity via the NRF2/GPX4 signalling. Together, arbutin preserves boar sperm during storage at 17°C by enhancing the antioxidant capacity via the NRF2/GPX4 signalling, laying the theoretical foundation for optimisation of the boar semen preservation diluent therefore facilitating the dissemination of superior porcine germplasm resources and improving the economic value.

Cold storage is a preferred method for short-term preservation of ram spermatozoa due to its superior fertility rates compared to cryopreservation. This study aimed to optimise the conditions for ram sperm preservation by evaluating the effects of osmolarity and egg yolk (EY) concentration in a syringe-filtered extender. In part A, semen samples were extended with solutions of varying osmolarities (330, 360, 390 and 420 mOsm/kg water). The 390 mOsm/kg solution demonstrated the best preservation of sperm viability, functional integrity and motility over 96 h of storage. In part B, different EY concentrations (10%, 15%, 20%, 25% and 30%) were assessed at the optimal osmolarity (390 mOsm/kg). A 20% EY concentration provided the most effective protection of sperm DNA, acrosome integrity and membrane functionality. Excessive EY levels (> 20%) negatively impacted sperm viability and induced higher lipid peroxidation. These findings emphasise the importance of balancing osmolarity and EY concentration for efficient cold storage of ram spermatozoa, enhancing the potential success of artificial insemination programs in sheep breeding.