Reproduction in Domestic Animals最新文献

Germplasm banking is a fundamental tool for the preservation of autochthonous breeds. Semen cryopreservation is effective for this task, but protocols are adapted to commercial species, and post-thawing sperm quality could be sensitive to environmental cues. We compared the post-thawing sperm quality in doses from the CBA-SERIDA bank in northern Spain for the Asturiana de la Montaña (AM) and Asturiana de los Valles (AV) autochthonous cattle breeds. Doses from 23 AM and 16 AV bulls (ejaculates from at least three different seasons) were assessed for motility (computer-assisted sperm analysis), physiology and chromatin status (flow cytometry) after thawing and after 5 h at 38°C. Data were analysed using linear mixed-effects and cosinor models for seasonal and breed effects and by correlations with the association of sperm quality with temperature-humidity index (THI), considering the interval of spermatogenesis plus maturation. The breed affected sperm quality, with higher motility for AV and higher apoptotic ratio, mitochondrial activity, reactive oxygen species, DNA fragmentation and chromatin immaturity for AM. However, seasonality effects were minimal, and THI was not associated with sperm quality. In summary, the season seems to be a minor factor in the post-thawing quality of the AM and AV autochthonous breeds, well-adapted to their local environment.

Pseudopregnancy (PSG) is one of the most common syndromes diagnosed after oestrous cycle in female dogs. We found a diagnosed prevalence of PSG at 30.81% among reproductive pathologies in bitch. Concentrated oestrous occurrences in spring and autumn influence PSG distribution. PSG onset is marked by behavioural changes, followed by physical signs (mammary enlargement and galactorrhea). The last oestrous-PSG onset interval ranged from 1 to 6 months (median = 3.0 months) and the median for the interval spaying-PSG onset was 7.0 days. Half of the cases were discharged after 16 days, surpassing recommended treatment periods for cabergoline (4-6 days) and metergoline (8 days). Although Elizabethan collars were recommended, actual compliance stood at two-thirds of cases. Our study highlights the possible underestimation of the PSG prevalence, probably due to lack of identification of clinical signs by owners. Further research is warranted to better understand possible risk factors, preventive measures or therapeutic options.

This preliminary study evaluated the biocompatibility of a novel degradable intravaginal plug contraceptive composed of PEG 4000 and chitosan in cats using haematological profiling and vaginal cytology. Five healthy, non-pregnant female cats were fully anaesthetised and fitted with an intravaginal plug (10 × 0.3 mm) using an applicator, following oestrogen administration 3 h prior. Blood samples were collected from the cephalic vein on days 0 (pre-insertion) and 3 and 7 (post-insertion). Vaginal cytology examinations were conducted on day 0 (pre- and post-oestrogen injection) and days 1, 3 and 7 post-insertion. Haematological parameters, including red blood cell count, haemoglobin levels, haematocrit values, total white blood cell count and differentiation, showed no significant changes after contraceptive insertion (p > 0.05). Vaginal cytology indicated an acute inflammatory response in one out of five subjects on day three post-insertion. The distribution of vaginal epithelial cells (parabasal, intermediate and superficial) remained unaffected by contraception. Oestrogen injection resulted in the dominance of superficial cells up to day 7 of observation (p < 0.05). Overall, PEG 4000 and chitosan-based intravaginal plug contraceptives demonstrated sufficient biocompatibility, indicating their potential as viable contraceptive options for feline use.

Sperm cryopreservation in small ruminant is an efficient strategy to distribute spermatozoa for reproductive programmes, but this process reduces the fertility potential of frozen-thawed spermatozoa. The aim of the current research was to evaluate the impact of different concentrations of cysteamine (CYS) in soybean lecithin (SL)-based medium on postthawed buck semen quality and fertility potential. Semen samples were collected from five bucks, twice a week, then diluted in the SL-based extender containing different concentrations of CYS as follows: extender containing 0 mM (control, C0), 1 mM (C1), 2 mM (C2), 4 mM (C4) and 8 mM (C8) CYS. Motility characteristics, membrane integrity, abnormal morphology, mitochondrial activity, acrosome integrity, viability, apoptotic-like changes, lipid peroxidation, DNA fragmentation, ROS concentration, pregnancy rate and kidding rate were evaluated after freeze-thaw process. In results, C1 resulted in greater (p ≤ 0.05) total motility, progressive motility, average path velocity, membrane integrity, mitochondrial activity, acrosome integrity, viability, pregnancy rate and kidding rate compared to the other groups. Furthermore, supplementation of freezing medium with 1 mM of CYS presented lower (p ≤ 0.05) apoptotic-like changes, lipid peroxidation, DNA fragmentation and ROS concentration compared to the other groups. On the other hand, C8 presented the least (p ≤ 0.05) total motility, progressive motility, average path velocity, membrane integrity, mitochondrial activity, acrosome integrity and viability as well as the highest (p ≤ 0.05) apoptotic-like changes, lipid peroxidation, DNA fragmentation and ROS concentration compared to the other groups. Therefore, supplementation of freezing medium with 1 mM CYS could be a helpful strategy to protect buck's spermatozoa quality and fertility potential during cryopreservation process.

Rabbits have played a significant role in both livestock production and the advancement of reproductive scientific research. Their unique biological traits, including induced ovulation and a reproductive process that closely mirrors that of humans, have been pivotal in their use as a model. Moreover, their body size is perfectly aligned with the 3Rs principles: Replacement, Reduction, and Refinement. Consequently, techniques for gamete collection and embryo recovery, followed by their use in artificial insemination or embryo transfer, are characterized by being minimally invasive. However, refining in vitro fertilization and embryo culture techniques continues to present challenges. The incorporation of cutting-edge genomic editing tools, such as CRISPR/Cas9, has reestablished rabbits as essential models in genetic and biomedical research, driving scientific progress. This review aims to describe the most effective reproductive biotechnologies for both male and female rabbits and how these methodologies are in line with the 3Rs principles-Replacement, Reduction, and Refinement-highlighting their significance in conducting ethical research.

The aim of this experiment was to assess the effect of media viscosity on ram sperm motility, kinematics and rheotaxis in vitro by using methylcellulose as a media thickener. Frozen-thawed semen of three rams was thawed and diluted in Tyrode's albumin lactate pyruvate (TALP) media supplemented with 0%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6% and 0.7% w/v of methylcellulose. Sperm motility and kinematic characteristics were analysed using computer-assisted sperm analysis (CASA). The rheotactic behaviour was assessed in a microfluidic channel, and the number of spermatozoa that passed the 10 mm point of a microfluidic channel over a 2min period against a flow rate of 30 μm/sec was assessed. The use of media with higher viscosity (higher levels of methylcellulose) resulted in significantly lower (p < .05) sperm motility and kinematic parameters. Moreover, higher levels of methylcellulose reduced (p < .05) the number of spermatozoa that exhibited positive rheotaxis. In conclusion, viscosity affected the kinematic properties and rheotactic behaviour of ram sperm.

This study evaluated the effect of prostaglandin F2α (PGF2α) associated with gonadotropin-releasing hormone (GnRH) for ovulation induction in precocious indicus heifers submitted to a fixed-time superovulation (SOV) programme. Precocious Nellore heifers (n = 35), aged 13 months, were subjected to the SOV protocol. On day 0 (D0), all animals received intravaginal insertion of a progesterone (P4) device along with intramuscular administration of 2 mg of oestradiol benzoate, plus 200 IU of follicle-stimulating hormone in decreasing doses, with 12-h intervals between D4 and D7, in addition to 150 μg of D-cloprostenol on D6 and device removal on D7. On D8, the donors received 10.5 μg of buserelin acetate and the treatment group received 300 μg of D-cloprostenol/PGF_2α. Artificial insemination was performed 12 h and 24 h after GnRH administration using frozen semen. On D15 of the protocol (i.e., D7 after insemination), the embryos were collected and evaluated. All animals passed through the control and treatment groups. Results were evaluated by analysis of variance using an adjusted mixed-effects model (p < 0.05). There was no difference in the total number of embryos between the control and treatment groups (10.40 ± 1.52 vs. 9.60 ± 1.36; p = 0.63) or viable embryos (6.30 ± 1.22 vs. 4.30 ± 0.71). For precocious indicus heifers, treatment with PGF_2α in association with GnRH did not affect embryo production in the fixed-time SOV protocol.

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.

The present experiment was carried out to investigate the role of Oxyrase in preserving the in vitro quality, redox status and in vivo fertility of crossbred boar spermatozoa. A total of 24 ejaculates from 6 crossbred (n = 4 from each boar) boars were collected and extended in Beltsville Thawing Solution (BTS) in 1:2 ratio and divided into three aliquots. The first aliquot served as a control (without Oxyrase). Rest of the two aliquots were supplemented with 0.125 (T1) and 0.25 IU/mL Oxyrase (T2). Semen samples were preserved at 15°C for 5 days and kinematics of spermatozoa by CASA, semen quality parameters and oxidative stress status were evaluated at 0, 72 and 120 h of storage. The findings of studies revealed that supplementation of Oxyrase at 0.25 IU/mL resulted in higher (p < 0.05) total motility, progressive motility, plasma membrane integrity, acrosome integrity and functional integrity of plasma membrane at 72 and 120 h in comparison to the control group. Mitochondrial membrane potential (MMP) was higher (p < 0.05) at 72 and 120 h, whereas higher (p < 0.05) DNA integrity was observed at 120 h in T2. The lipid peroxidation (LPO) was lower (p < 0.05) and superoxide dismutase activity (SOD) and total antioxidant capacity (TAC) were higher (p < 0.05) in the T2 group at 120 h as compared to control. In vivo fertility trials indicated a higher (p < 0.05) litter size in T2 in comparison to other groups. The study concluded that the inclusion of Oxyrase at 0.25 IU/mL in the extender protects the crossbred boar spermatozoa against oxidative damage and improves the in vivo fertility.