Search Results (192)

The corpus luteum (CL) is a transient gland that can directly influence follicular dynamics and oocyte quality. The objective of this study was to evaluate the influence of the absence or presence of a small (≤3 mm), medium (4–8 mm), or large (>8 mm) CL in slaughterhouse ovaries on in vitro embryo production. Cumulus–oocyte complexes (COCs) were collected from each group of ovaries and matured in TCM-199 medium, plus hormones and fetal bovine serum. Fertilization was performed with fresh semen from a Katahdin ram of known fertility. Embryo development was carried out in commercial sequential media for 72 and 96 h, until the blastocyst stage. The number of follicles (2–6 mm in diameter) and COCs were influenced by the presence of CL, which was higher (p < 0.05) in the Large CL group (5.51 ± 0.33 and 3.62 ± 0.27) compared to the Without CL group (4.54 ± 0.19 and 2.62 ± 0.14, respectively), with no difference between the CL sizes. Likewise, the diameter and area of the COCs were higher in the Small CL group of ovaries compared to the Without CL group. In the Large CL group of ovaries, 9% more morulae (p < 0.05) were obtained compared to the Without CL group; in the Medium CL group, 13% more blastocysts were obtained compared to the Without CL group. However, in the hatching capacity and diameter of blastocysts, no statistical difference was evident (p > 0.05). In conclusion, the presence and size of the CL in the ovaries of slaughtered sheep influence the productive efficiency of embryos in vitro under the conditions in which the present study was carried out. Full article

The cryopreservation of rabbit semen is a valuable strategy for genetic resource preservation and efficient artificial insemination, but outcomes remain inconsistent, partly due to variations in sperm concentration per dose. This study aimed to evaluate the in vivo effects of different sperm concentrations (15, 25, 35, 55, and 75 million per straw) on fertility, prolificacy, and offspring growth in nulliparous and multiparous does. A total of 384 rabbit females were inseminated using frozen–thawed semen, and their reproductive performance was compared with fresh semen. Fertility and kindling rates varied with sperm concentration and parity: nulliparous does showed the highest fertility at 15 million sperm/straw (84.4%), while multiparous does reached peak values at 25–55 million/straw (78.1–81.3%). Litter size and live-born kits were consistently higher in multiparous than in nulliparous does. Offspring body weight at 19 and 60 days was influenced by both sperm concentration and maternal parity, with better growth generally observed in multiparous groups. Weaning success remained high across all groups. Our results indicate that sperm concentrations ranging from 15 to 35 × 10⁶/straw are the most suitable for cryopreservation, as they maintain high fertility, prolificacy, and offspring growth, comparable to fresh semen. These results confirm that optimizing sperm concentration during cryopreservation improves reproductive efficiency and that tailoring insemination strategies to the physiological status of the female enhances outcomes. The results provide useful recommendations for improving cryopreservation techniques in rabbit breeding programs. Full article

Infertility is a significant global health concern, and incorporating antioxidants into sperm preparation media is one strategy to enhance sperm quality and decrease infertility rates. This study aimed to investigate the phytochemical compounds of red cotton stamen extracts and their effects as antioxidants in improving the quality of bull frozen semen. Among the extracts, RCU contained the highest levels of total phenolics, total tannins, and total monomeric anthocyanins along with the strongest ABTS free radical scavenging activity and protein denaturation inhibition. Exposing sperm to FeSO₄-induced oxidative stress resulted in significantly reduced motility, viability, and normal morphology. However, treatment with RCD, RCU, and RCM improved these parameters. Additionally, the FeSO₄-induced group showed elevated levels of reactive oxygen species (ROS) and advanced glycation end products (AGEs) compared to the normal control, whereas all red cotton stamen extracts effectively reduced these levels. In conclusion, red cotton stamen extracts, rich in phenolic bioactive compounds, demonstrated strong free radical scavenging capacity and improved sperm motility, viability, and morphology by neutralizing free radicals and enhancing antioxidant defenses. These findings suggest that the red cotton stamen extracts, particularly RCD and RCU, offer benefits for sperm preservation. Full article

Infertility is a complex and common problem in reproductive medicine consultations. Three factors must be examined during the preconception phase: breeding management, the fertility of the bitch, and the fertility of the stud dog. Among these factors, improper breeding management remains the main cause of reproductive failure, with accurate recognition of ovulation being crucial for successful mating. Artificial insemination allows for a thorough evaluation of semen quality compared to natural mating. In addition, genetic selection, nutritional factors, and reproductive health management can either impair or improve the fertility of females and males. Idiopathic infertility can occur in bitches, but it is important to rule out other possible causes first. In bitches with irregular estrus cycles, ovarian dysfunction and endocrine imbalances should be investigated. In bitches with regular cycles, uterine disorders such as cystic endometrial hyperplasia, endometritis or congenital anomalies may be the cause. Both mating-related and chronic endometritis are recognized as contributing factors to infertility. Infectious agents, particularly Brucella spp. and Mycoplasma spp., should also be evaluated, although interpretation of Mycoplasma test results requires caution. In males presenting with poor semen quality, potential causes include infectious diseases (with brucellosis always requiring exclusion), hormonal imbalances, and the impact of exogenous treatments. The article underscores the critical role of comprehensive diagnostic protocols, proactive health surveillance, and data-driven breeding strategies in systematically addressing this multifaceted challenge. Full article

Sperm membrane stability is a key factor in determining sperm viability and fertilization capability, with broad implications ranging from basic reproductive biology to livestock breeding practices. This comprehensive review examines the structural and functional mechanisms underlying sperm membrane integrity, including defensive barrier functions, potentiometric ion channel regulation, and motility modulation that collectively optimize sperm survival, motility, and fertilization potential. Environmental factors such as temperature fluctuations, abnormal pH levels (outside the optimal 7.2–8.2 range), pathological conditions, and hormonal imbalances can compromise membrane stability by inducing oxidative stress and protein denaturation. Key regulatory proteins, notably NPC2 for cholesterol homeostasis, Flotillin proteins for lipid raft organization, and Annexin V for membrane repair mechanisms, demonstrate essential roles in maintaining structural integrity. In livestock reproduction, membrane stability research facilitates the optimization of cryoprotectant formulations and freezing protocols, resulting in 15–25% improvements in post-thaw sperm survival rates and enhanced artificial insemination success. These findings provide valuable insights for advancing assisted reproductive technologies and improving reproductive efficiency in animal husbandry. Full article

This study aimed to investigate population genetic differences related to reproductive traits between Duroc and Yorkshire (Dutch Large White) pigs using two approaches: linear mixed models that dissect additive and dominant effects, and selective sweep analysis. (1) Methods: Genome-wide single-nucleotide polymorphism (SNP) data of 3917 Duroc and 3217 Yorkshire pigs were analyzed. The first principal component (PC1) was used as a simulated phenotype to capture population-level variance. Additive and dominant genetic effects were partitioned and evaluated by using the combination of the linear mixed models (LMM) and ADDO’s algorithm (LMM + ADDO). In parallel, selective sweep signals were detected using fixation index (F_ST) and nucleotide diversity (θ_π) analyses. A comparative assessment was then conducted between the LMM + ADDO and the selective sweep analysis results. Significant loci were annotated using quantitative trait loci (QTL) databases and the Ensembl genome browser. (2) Results: There are 39040 SNPs retained after quality control. Using the LMM + ADDO framework with PC1 as a simulated phenotype, a total of 632 significant SNPs and 184 candidate genes were identified. Notably, 587 SNPs and 171 genes were uniquely detected by the LMM + ADDO method and not among loci detected by the top 5% of F_ST and θ_π values. Key candidate genes associated with litter size included HSPG2, KAT6B, SAMD8, and LRMDA, while DLGAP1, MYOM1, and VTI1A were associated with teat number traits. (3) Conclusions: This study demonstrates the power of integrating additive and dominant effect modeling with population genetics approaches for the detection of genomic regions under selection. The findings provide novel insights into the genetic architecture of reproductive traits in pigs and have practical implications for understanding the inheritance of complex traits. Full article

This study evaluates the effectiveness and financial impact of treating anoestrus dairy cows using a modified DO protocol. Among the 350 cows included in the study, 142 (40.6%) were identified as anoestrus. The average daily milk production, days in milk at artificial insemination (AI), number of AIs, and parity were 33.8 ± 6.8 kg, 152.6 ± 24.4 days, 1.3 ± 0.2 AIs, and 1.9 ± 0.8 lactations, respectively. To assess embryo survival in anoestrus dairy cows undergoing the modified DO protocol, two groups were established. The experimental group (E group, n = 74) received the GnRH agonist gonadorelin five days after TAI as part of the DO protocol. The control group (C group, n = 68) received only the DO protocol. The pregnancy rates and cumulative pregnancy rates were significantly higher in the E group (35.1% and 56.8%) compared with the C group (26.5% and 45.6%, p < 0.05). A binary logistic regression analysis indicated that the interaction between treatment and anoestrus status considerably affected the pregnancy rate (p < 0.001) and the occurrence of accessory corpus luteum (aCL, p < 0.0001). The UW-DairyRepro$ decision support tool utilized in this study, indicated that implementing this approach could increase the net present value (NPV) by USD 54.2/anoestrus cow/year. Full article

Artificial insemination (AI) is essential in intensive pig production, which significantly depends on semen quality from boars selected for health, genetics, and fertility. While AI aims to improve productivity, larger litters often result in smaller and less resistant piglets. Beyond fertility and genetic traits, boars also influence offspring health. This study investigated the relationship between sperm parameters of highly fertile boars and both reproductive outcomes and piglet physiological indicators. Multivariate analysis revealed significant paternal effects on blood markers reflecting organ function, including those of the pancreas, liver, and kidneys, as well as on glucose homeostasis, lipid metabolism, oxidative stress, protein and carbohydrate metabolism, muscle contraction, and neural signaling. Notably, sperm velocity was correlated with mitochondrial function, which is crucial for sperm motility, capacitation, DNA integrity, and embryo development—factors likely linked to healthier, more resilient offspring. Boars transmitting superior sperm velocity, erythropoiesis efficiency, and oxygen transport capacities produced piglets with better glucose regulation, growth, and resistance to neonatal hypoglycemia. These findings underscore the broader impact of sperm quality on offspring vitality and suggest that advanced sperm analysis could improve boar selection and enable more effective, health-oriented breeding strategies. Full article

In recent decades, Blanket Dry Cow Therapy (BDCT) has been regarded as a cornerstone strategy for the control of mastitis in dairy cows during the dry period. However, concerns regarding the rising incidence of antibiotic resistance and the associated zoonotic risks have prompted a paradigm shift, leading to intensified research into alternative management approaches. In response, many countries have adopted a more targeted approach, known as Selective Dry Cow Therapy (SDCT), which focuses on the therapeutic use of antibiotics, administered only to cows or quarters that are either infected or at high risk of infection during the dry period. This review provides a comprehensive synthesis of the scientific literature regarding the main methods for selecting animals for SDCT, the impact of this strategy on udder health, milk production, farm economics, and antibiotic consumption, as well as the factors that may influence its effectiveness. Over time, a range of methods have been developed to identify infected animals, including bacteriological culture, somatic cell count (SCC), differential somatic cell count (DSCC), and the California Mastitis Test (CMT), which are often used alone or in combination with clinical mastitis history and/or parity. Among these methods, SCC has proven to be the most economically viable and best suited for practical use, while its combination with DSCC has been shown to significantly enhance diagnostic accuracy. According to the studies reviewed, SDCT is a safe and effective strategy for maintaining udder health and farm profitability, as long as infected cows are accurately identified, and internal teat sealants are used in quarters not treated with antibiotics during the dry period. However, since udder health is influenced by herd characteristics, management practices, and regional pathogens, the findings cannot be universally applied and must be adapted to each herd’s specific conditions. Full article

Meloxicam has been identified as an adjuvant therapeutic component in the management of bovine uterine diseases, exhibiting anti-inflammatory and antioxidant effects. However, the mechanisms underlying its antioxidant actions in the context of bovine uterine diseases remain incompletely understood. The objective of this research was to determine whether meloxicam exerts its antioxidant effects through the Nrf2/HO-1 signaling pathway. By employing N-acetylcysteine (NAC), a scavenger of reactive oxygen species (ROS), along with inhibitors directed against heme oxygenase-1 (HO-1) or nuclear factor erythroid 2-related factor 2 (Nrf2), we investigated the dynamic changes in oxidative stress markers (ROS and malondialdehyde) and antioxidant indices (comprising catalase, superoxide dismutase, and glutathione), as well as the expression profiles of Nrf2 and inflammation-associated genes and proteins in bovine endometrial epithelial cells (BEECs) subjected to lipopolysaccharide (LPS) stimulation. As a result, meloxicam alleviated the LPS-induced elevation of oxidative stress marker levels and the reduction in antioxidant enzyme activities and antioxidant substance contents in BEECs. Compared to NAC, meloxicam demonstrated superior efficacy in activating the Nrf2 pathway, with the promotion of NRF2 expression (~1.6-fold) and nuclear translocation. The pretreatment of cells with HO-1 or Nrf2 inhibitors markedly attenuated the antioxidant activity of meloxicam. In summary, meloxicam primarily alleviates LPS-induced oxidative stress through the activation of the Nrf2/HO-1 pathway in BEECs. Full article

The estrous cycle involves hormonal fluctuations that influence serotonin (5-HT) concentrations and immune cell activity. During the follicular phase, estrogen increases 5-HT synthesis, enhancing cellular responses to inflammation. In contrast, in the luteal phase, progesterone suppresses immune function, reducing 5-HT availability. Age-related changes in hormone concentrations can affect these processes, potentially altering cellular responses and 5-HT dynamics in the oldest females. This study hypothesizes the relationship between 5-HT and blood cells in healthy cyclic mares, considering age as an influencing factor. Understanding these interactions offers insights into reproductive health and immune regulation in equine species. The aim was to describe the interaction between 5-HT and blood cells in twenty-five healthy cyclic Spanish Purebred mares, evaluating the effect of aging. For this purpose, the mares were classified into two age groups as follows: from 4 to 9 years (n = 12 younger mares) and from 10 to 15 years (n = 13 older mares). Younger and older mares showed an opposite 5-HT trend at +5 and +16 day of cycle (d), with greater concentrations in younger mares (p < 0.05) and lower values in older mares (p < 0.05) than at −5 and 0 d. Older mares showed a lower 5-HT concentration at +5 and +16 d (p < 0.05) than younger mares. Mares of both ages showed a superimposed WBC trend, with the greatest number both at −5 and 0 d (p < 0.05). Older mares showed a lower WBC number at −5 d (p < 0.05), and lower NFS and LYMPH numbers both at +5 and +16 d (p < 0.05) than younger mares; the latter showed the lowest NFS number at +16 d, and LYMPH number at +5 and +16 d. Mares of both ages showed a similar trend for the N/L ratio. Older mares showed a lower MON number at +5 d (p < 0.05), greater PLTs at +5 and +16 d (p < 0.05) than younger mares, and a greater PLT number at −5 and 0 d than at +5 and +16 d (p < 0.05). The activity of 5-HT is regulated by its rate of synthesis, release, and metabolism according to age. Aging reduced the 5-HT concentrations and the number of WBCs, NFSs, LYMPHs, and MONs, inducing correlations among these and 5-HT in healthy young and old cyclic mares. Full article

Ferroptosis is implicated in cryodamage to sheep sperm, potentially due to glutathione peroxidase 4 (GPX4) degradation during freezing; however, the pathway underlying GPX4 degradation remains unclear. In this study, a comparison of cryoprotective effects between the autophagy inhibitor chloroquine (CQ) and the ubiquitination inhibitor MG132 revealed that 5 μM CQ treatment significantly enhanced the motility (p < 0.01) and sperm plasma membrane integrity rate (p < 0.01) of frozen–thawed sperm; no protective effects were observed in any MG132 treatment group. Mechanistic analysis indicated that CQ treatment substantially restored GPX4 protein expression (p < 0.01), and concurrently reduced lipid peroxidation (p < 0.01) and free iron ion accumulation (p < 0.01), in frozen–thawed sperm. These findings suggest that GPX4 degradation during cryopreservation occurs via the autophagy pathway. This study established a ferroptosis–GPX4–autophagy axis during sheep sperm cryopreservation and identified autophagy-mediated GPX4 loss as a potential target for enhancing sperm cryoprotection. Full article

Treating endometritis is one of the major challenges faced by veterinarians. The effect of post-insemination intrauterine infusion Wharton’s jelly mesenchymal stromal/stem cell-derived conditioned medium (WJ-MSC-CM) on the uterine response and pregnancy outcomes in problem mares was evaluated in this study. The cycles of 12 problem mares were treated seven/eight hours after insemination with intrauterine infusion of 20 mL of WJ-MSC-CM (TRT) or non-conditioned Ringer’s lactate solution (CTR). Before (PRE) and 12 h after (POST) treatment, an ultrasonographic examination and a low-volume flush (LVF) for efflux clarity evaluation and bacteriological and cytological analysis were made. Pregnancy diagnosis was performed at 14 days and confirmed at 60 days after ovulation. A decrease (p < 0.05) in polymorphonuclear neutrophils infiltration and a trend toward significance in LVF efflux clarity (p < 0.1) were observed in TRT cycles. The TRT (50%) had a higher pregnancy rate (p < 0.05) than CTR group (0%) at first cycle. Only a trend toward significance was observed comparing pregnancy frequencies between the two groups (CTR 12.5% vs. TRT 54.5%), the pregnancy rate of TRT cycles was comparable to that of normal mares (p > 0.05) and higher (p < 0.05) than that reported for problem mares in the literature. Post-insemination uterine infusion of WJ-MSC-CM in mares restores pregnancy rates to normal levels, by its anti-inflammatory effect. Full article

Congenital defects are among the leading causes of neonatal mortality in small animals. Among them, cleft palate is one of the most commonly found malformations in dogs. Appropriate clinical management and surgical correction are determining factors for the survival of puppies affected by this alteration. Thus, the objective of this study is to describe 10 clinical cases of successful clinical management of cleft palate, highlighting the therapeutic strategies used, the results obtained, and the evolution of patients after treatment. Ten neonatal dogs of three breeds were treated by the Small Animal Reproduction Service of FMVZ, Unesp—Botucatu: French Bulldog (6), Pug (3), and American Bully (1) presented with cleft palate at birth or during the first week of age. Patients underwent clinical and nutritional management, in addition to immunological support. At four months of age, the patients underwent medially positioned flap repair. The animals were fed via an esophageal tube for 10 days after surgery. The clinical management proved to be effective since, throughout the follow-up, the animals showed good development and did not present complications arising from the cleft palate, and the surgical procedures were successful, restoring the quality of life of the animals. Full article