Reproduction in Domestic Animals最新文献

{"title":"Follicular B-Mode Echotexture Parameters at P4 Insert Removal and Their Association With Pregnancy Outcomes in Beef Cows Undergoing Timed AI Protocol.","authors":"César Augusto Pinzón-Osorio, Dionet Keny Bellido-Quispe, Marco Alves Machado, Fernando Caetano de Oliveira, José Luiz Rodrigues, Marcelo Bertolini","doi":"10.1111/rda.70018","DOIUrl":"https://doi.org/10.1111/rda.70018","url":null,"abstract":"<p><p>This study aimed to determine the relationship between echogenicity and heterogeneity of ovarian structures and cyclicity status, estrus expression and pregnancy per artificial insemination (P/AI) in multiparous beef cows during timed-artificial insemination (TAI). An ultrasound ovarian examination was carried out in 406 crossbred suckled cows at progesterone (P4) insert removal on D8 of a TAI protocol and at pregnancy diagnosis 30 days after TAI. Follicular (antrum, wall and perifollicular stroma) and luteal morphometry, and echotexture and heterogeneity parameters were analysed on D8 and D30 after TAI, respectively. Follicles that did not reach divergence (< 8.5 mm) at P4 removal had higher antral echotexture and heterogeneity values (p < 0.0001) than those that surpassed divergence (> 8.5 mm). Lower follicular antrum echotexture levels at P4 removal positively correlated with subsequent estrus expression and pregnancy outcomes (p < 0.05), and negatively with follicle size (p < 0.0001). Luteal echotexture varied according to the originating follicle size (p < 0.05), with no differences between pregnant and non-pregnant cows 30 days after TAI. Cows had higher odds of estrus expression (Se, 70.61%; Sp, 61.05%; AUC 0.80; p < 0.0001) and attaining P/AI (Se, 64.52%; Sp, 61.05%; AUC 0.73; p < 0.0001) with lower follicular antrum echotexture (overall cut-off ≤ 14.25). The results show that echotexture values in antral follicles on D8 are strongly associated with pregnancy outcomes and may be useful for predicting success in TAI protocols.</p>","PeriodicalId":21035,"journal":{"name":"Reproduction in Domestic Animals","volume":"60 3","pages":"e70018"},"PeriodicalIF":1.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143543293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultrasonic Evaluation of the Corpus Luteum in Alpacas With Embryo Removal on Day 9 Post-Mating.","authors":"Ariadna Yáñez, Almudena Isabel Arrayás, Uri Harold Perez-Guerra, Alicia María López, Edita Yola Torres, Jesús Manuel Palomino","doi":"10.1111/rda.70047","DOIUrl":"10.1111/rda.70047","url":null,"abstract":"<p><p>The objective of the present study was to determine the diameter, area, circumference, and blood flow of the corpus luteum (CL) using transrectal ultrasonography in female alpacas with and without the presence of an embryo on Day 9 post-mating, the time of maternal recognition of pregnancy (MRP). For this purpose, 12 female alpacas with follicles ≥ 7 mm were mated with fertile males and treated with 0.0084 mg of buserelin acetate (Day 0). After that, the females were randomly classified into 2 groups (6 animals/group): (1) CL with embryo and (2) CL without embryo (embryo removed from the uterine horn on Day 9). In both groups, transrectal ultrasonography was performed on Day 2 to determine ovulation, and on Days 5, 7, 9, 11, and 13 to evaluate the CL. The data were analysed using repeated measures ANOVA. The diameter (mm), total area (mm²), circumference (mm), and blood flow (%) of the CL were significantly decreased in the CL without embryo group on Days 11 and 13 (6.9 ± 0.6 and 2.9 ± 1.1, 48.3 ± 5.6 and 12.3 ± 4.7, 22.4 ± 1.9 and 7.4 ± 2.5 and 39% and 55%, respectively) compared to the CL with embryo group (12.1 ± 0.9 and 12.1 ± 0.6, 111.1 ± 17.1 and 107.5 ± 8.8, 37.2 ± 2.8 and 37.0 ± 1.7, and 3% and 3%, respectively). In conclusion, the CL characteristics in alpacas with embryo removal changed drastically after Day 9, presenting progressive regression in size and blood flow from Day 11 to 13. These results might indicate that the presence of an embryo on Day 9 is necessary to trigger the signal that prevents luteolysis in this species.</p>","PeriodicalId":21035,"journal":{"name":"Reproduction in Domestic Animals","volume":"60 3","pages":"e70047"},"PeriodicalIF":1.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143606210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PCR-Based Amplification of Amelogenin Gene for Ovine Sex Determination Using Primers of Different GC Percentage.","authors":"Anupama Karimpat, Ashish Mishra, Sudhir Chandra Roy, Ippala Janardhan Reddy","doi":"10.1111/rda.70026","DOIUrl":"https://doi.org/10.1111/rda.70026","url":null,"abstract":"<p><p>The identification of species and their sex from small biological samples is of scientific interest in forensic science. Various identification techniques have been developed; however, DNA-based PCR is the most specific and sensitive technique compared to protein-based methods. Although PCR amplification of the amelogenin (AMEL) has been used in different species for sex determination, the reliability of the AMEL test may sometimes be challenged due to amplification failure of AMEL Y in males, resulting in incorrect gender identification. Therefore, this study aimed to establish a simple, reliable and accurate PCR protocol for the amplification of the AMEL gene from blood gDNA isolated by a single-step DNA isolation method using primers of different GC% to ascertain the sex of ovine. This methodology may also be applicable to various biological samples for sex determination. It was concluded that the touchdown PCR was more suitable for GC-rich primers and low GC% primers were suitable with modified conventional PCR for gender identification. The use of PCR enhancers at denaturation temperatures of 94°C and 95°C was found ineffective for the amplification of AMEL to determine the sex. In summary, all primers used showed successful amplification.</p>","PeriodicalId":21035,"journal":{"name":"Reproduction in Domestic Animals","volume":"60 3","pages":"e70026"},"PeriodicalIF":1.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143634519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Progesterone and Oestradiol-17β Levels and Their Associations With Male Acceptance and Pregnancy in Female Alpacas (Vicugna pacos).","authors":"Toru Egi, Masaaki Hanada, Arisa Iiduka, Yuji Tokura, Rodrigo H Kawabata, Alejandro Bonifacio Flores, Tomás J Acosta","doi":"10.1111/rda.70041","DOIUrl":"https://doi.org/10.1111/rda.70041","url":null,"abstract":"<p><p>Alpacas are important livestock animals in the Andean highlands of South America. However, their reproductive efficiency is low under natural conditions. In this study, we analysed the oestradiol-17β (E2) and progesterone (P4) levels in the serum and faecal samples of female alpacas before exposure to males for mating to determine whether E2 and P4 affect male acceptance and pregnancy in alpacas. In Experiment 1, faecal samples were collected from nine female alpacas prior to exposure to males for mating to evaluate the effects of premating faecal hormone levels on mating behaviour. In Experiment 2, four of nine female alpacas, which had not previously accepted mating, were injected intramuscularly with oestradiol benzoate (EB). Mating receptivity after EB administration, serum E2 levels before and after EB administration and pregnancy were then evaluated. In both experiments, P4 and E2 were measured in serum and faecal samples using ELISA kits after extraction with diethyl ether and methanol respectively. In Experiment 1, of 23 contacts with males in the mating test, females accepted males 12 times and rejected them 11 times. The proportion of females rejecting males increased as the premating faecal P4 level increased (p = 0.021) and the proportion of females accepting males increased as the faecal E2 level increased (p = 0.035). In Experiment 2, serum E2 levels were higher 2 h after injection than before EB injection (p < 0.05). Alpacas that refused to mate before injection accepted mating 2 h after EB treatment. All alpacas with faecal E2 levels more than 0.5 ng/mg of dry matter before mating had higher P4 levels a month after mating than those with low E2 levels (p < 0.05) and were pregnant. In conclusion, this study showed that measurement of faecal E2 levels can help in determining the appropriate breeding time and that EB treatment improves reproductive performance in alpacas.</p>","PeriodicalId":21035,"journal":{"name":"Reproduction in Domestic Animals","volume":"60 3","pages":"e70041"},"PeriodicalIF":1.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143606138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Equine Chorionic Gonadotropin on Follicular and Luteal Vascularisation and Progesterone Production in Murrah Buffaloes Subjected to Ovulation Synchronisation.","authors":"Felipe Rydygier de Ruediger, Nélcio Antonio T de Carvalho, Viviane M Codognoto, Ariane Dantas, Paulo H Yamada, Rogério Antônio de Oliveira, João Carlos Pinheiro, Rogério A Almeida Filho, Eunice Oba","doi":"10.1111/rda.70027","DOIUrl":"https://doi.org/10.1111/rda.70027","url":null,"abstract":"<p><p>This study evaluated the effect of equine chorionic gonadotropin (eCG) on ovarian vascularisation and plasma progesterone (P4) levels in Murrah buffaloes during an ovulation synchronisation protocol. Twenty buffaloes were divided into two groups: with eCG (n = 20) and without eCG (control, n = 20) in a crossover design. A 1.0 g progesterone intravaginal device (DIB) was inserted and 2 mg oestradiol benzoate was administered intramuscularly on Day 0. On Day 9, DIB was removed, PGF2α was administered to all animals and eCG was given to half. GnRH was administered on Day 11. Daily Doppler ultrasounds assessed follicular and luteal development and vascularisation from D9 to D16 and on Days 20, 24, 28 and 32. Blood samples were collected before each ultrasound to analyse plasma P4. Ovulation occurred on Day 13.42 ± 1.17 in the eCG group (19/20) and 13.53 ± 0.19 (14/20) in the control (p = 0.34). The ovulation rate was higher in the eCG group (95%) than in the control (70%). eCG increased the vascularised follicle perimeter on Days 11 (p = 0.018) and 12 (p = 0.03) and enhanced corpus luteum (CL) diameter on Day 16 (p < 0.001). A larger vascularised area was observed on Days 14-16, 20 and 24 (p < 0.05). P4 concentrations were higher in the eCG group on Days 15, 16, 20 and 24 (p < 0.05). Significant correlations were found between CL size, vascularisation and P4 concentration (r = 0.75, p < 0.001). In conclusion, eCG improves ovarian vascularisation, ovulation rates and plasma P4 levels, supporting its use to enhance reproductive performance in buffalo herds.</p>","PeriodicalId":21035,"journal":{"name":"Reproduction in Domestic Animals","volume":"60 3","pages":"e70027"},"PeriodicalIF":1.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143543249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beneficial Effects of N-Acetyl Cysteine in the Different Equilibration Times on Post-Thawed Rooster Sperm Quality.","authors":"Zeynab Zanganeh, Maryam Hezavehei, Iman Halvaei, Mohsen Sharafi","doi":"10.1111/rda.70035","DOIUrl":"https://doi.org/10.1111/rda.70035","url":null,"abstract":"<p><p>Cryopreservation is the best method for preserving rooster sperm, especially in declining indigenous breeds. Cryopreserved semen is significantly compromised due to equilibration time, cold shock and oxidative stress encountered during the freezing-thawing process. To improve the quality and fertility of thawed semen, it is essential to protect sperm cells from peroxidative damage. This study assessed the effects of N-acetyl cysteine (NAC), an antioxidant supplement, on the functional parameters of thawed rooster sperm after pre-freezing equilibration periods of 2 and 4 h. Samples were collected from 10 male Ross 308 broiler breeders and diluted with Beltsville extenders containing different concentrations of NAC (0, 0.1, 1 and 10 mM/mL) during equilibrium periods of 2 and 4 h before freezing. Our findings showed that NAC-0.1 and NAC-1 groups in 2 h increased significantly total and progressive motility (59.85 ± 3.73, 59.67 ± 3.73, 42.85 ± 2.64 and 42.80 ± 2.64, respectively), viability, and plasma membrane functionality (62.45 ± 3.51, 62.36 ± 3.51, 56.81 ± 3.51 and 56.82 ± 3.56, respectively) compared to the control groups. Furthermore, NAC-0.1-2 h and NAC-1-2 h demonstrated the lowest levels of apoptosis and intracellular reactive oxygen species (ROS), as well as the highest mitochondrial membrane potential in comparison to the control groups. These findings indicate that NAC-0.1 and NAC-1 are effective in maintaining the quality of thawed rooster sperm during a 2-h equilibration period.</p>","PeriodicalId":21035,"journal":{"name":"Reproduction in Domestic Animals","volume":"60 3","pages":"e70035"},"PeriodicalIF":1.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143586693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Contraceptive Strategies for Female Cattle: Efficacy and Zootechnical Aspects.","authors":"Daniela Guarchez Adamich, Lucas Cardoso Azeredo, Fabiane Pereira de Moraes, Daniele Missio, Fernando Caetano de Oliveira, Bernardo Garziera Gasperin","doi":"10.1111/rda.70032","DOIUrl":"https://doi.org/10.1111/rda.70032","url":null,"abstract":"<p><p>Unwanted pregnancies at the slaughterhouse are a recurring problem globally, compromising ethical aspects and animal welfare, and causing production losses. This review explores contraceptive strategies for female cattle, focusing on both management practices and suppression of the estrous cycle and/or fertilisation. Contraceptive techniques such as surgical castration, emasculation of the ovaries with rubber rings, intrauterine devices (IUDs), GnRH agonist implants, and immunocastration are discussed. Surgical castration, although efficient, is an invasive procedure that compromises animal welfare. Alternative methods, such as IUDs and GnRH implants, lack commercially available products and large-scale efficacy studies. Immunocastration is easy to apply and does not require specialised equipment, but also requires further studies to evaluate its effects on animal performance. Despite the various contraceptive alternatives available, the high number of pregnant females slaughtered highlights the need for awareness among producers and technicians, as well as more in-depth studies on strategies that can promote benefits to animals and production.</p>","PeriodicalId":21035,"journal":{"name":"Reproduction in Domestic Animals","volume":"60 3","pages":"e70032"},"PeriodicalIF":1.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143568035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phytoestrogens Modulate Bovine G Protein-Coupled Receptors and Play a Critical Role in Regulating Reproductive Functions in Animals.","authors":"Muhammad Safdar, Yasmeen Junejo, Muhammad Tariq, Muhammad Mazhar Ayaz, Safdar Imran, Armughan Ahmed Wadood, Mohammad Abul Farah","doi":"10.1111/rda.70033","DOIUrl":"https://doi.org/10.1111/rda.70033","url":null,"abstract":"<p><p>Phytoestrogens are secondary plant metabolites that are structurally analogous to endogenous oestrogens and bind to Bovine G Protein-Coupled Receptors (GPCRs) in animals. Their interaction with GPCRs activates intracellular signalling cascades, such as the cAMP/PKA pathway, which plays a crucial role in ovarian follicle development and luteinisation. These interactions may enhance reproductive performance by improving fertility, synchronising estrous cycles, and promoting ovulation. Phytoestrogens also influence the regularity and timing of the estrous cycle, offering potential applications in estrous synchronisation and reproductive management. In this study, molecular docking was conducted on 12,000 phytochemicals to identify potential GPCR ligands. From this extensive screening, five compounds with the highest binding affinities to GPCRs were selected. Notably, Genistein and Apigenin emerged as top candidates, with docking scores (-8.58 kcal/mol and -8.27 kcal/mol) and lower RMSD values (0.69 and 1.30) compared to synthetic GPCR agonists such as Estradiol (-6.07 kcal/mol and 1.02), respectively. Molecular dynamics simulations (MDS) confirmed the stability of these phytoestrogen -GPCR complexes, suggesting effective and sustained interactions. The screened phytoestrogens demonstrated favourable pharmacokinetic profiles, including non-toxicity, non-carcinogenicity, and high gastrointestinal absorption, positioning them as viable candidates for enhancing reproductive performance in dairy cattle through GPCR modulation. These findings suggest that phytoestrogens could be used as feed additives to improve reproductive outcomes, offering a novel approach to modulate GPCR pathways in dairy animals.</p>","PeriodicalId":21035,"journal":{"name":"Reproduction in Domestic Animals","volume":"60 3","pages":"e70033"},"PeriodicalIF":1.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143674513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Alterations in the Vaginal Vascular Perfusion, Chromoendoscopy and Oxidative Stress in Mares With Vaginitis and Endometritis.","authors":"Elshymaa A Abdelnaby, Naglaa A Abd ElKader, Shimaa G Yehia, Noha Y Salem, Eman S Ramadan, Marwa S Khattab, Haithem A Farghali, Ibrahim A Emam","doi":"10.1111/rda.70040","DOIUrl":"https://doi.org/10.1111/rda.70040","url":null,"abstract":"<p><p>This study aimed to demonstrate the vaginal tissue alterations via vaginal biopsy and hemodynamic alterations by introducing chromoendoscopy to analyse the effect of equine vaginitis on the oxidative and hormonal profile. Mares were divided into normal mares (N = 10) and affected mares (N = 10). Animals were subjected to Doppler ultrasonographic evaluation, endoscopic examination, oxidative stress was estimated, and biopsy samples were taken for histopathology and immunohistochemistry. Uterine body (UB) thickness (mm), circumference (mm) and area (mm²) elevated significantly in infected mares. Vaginal vascularization area elevated in the infected animals. The pattern was determined using pulsed wave Doppler. Both Doppler indices and systolic velocity declined significantly in both arteries (pudendal artery [vestibular B] and vaginal artery blood flow) in the infected group. Estradiol, insulin-like growth factor (IGF-1) and nitric oxide metabolites (NOMs) were significantly affected by the infection in mares. A significant increase in malondialdehyde (MDA) associated with a significant decrease in total antioxidant capacity (TAC) was observed in the vaginal fluid of affected animals. Chromoendoscopic examination revealed hypervisible inflamed os-cervix and vaginal wall. After methylene blue (MB) addition, there was bluish discolouration of the os-cervix, faint and deep bluish discolouration of the vaginal mucosa. The vaginitis group had a corrugated deep bluish colour in the mucosa. The expression of NF-κβ P65 was not observed in control; however, it was expressed in the mononuclear cells infiltrating the submucosa of the vagina of the affected animal. In conclusion, Equine vaginitis is associated with decline in both Doppler indices with elevation of MDA and a declination of TAC, in addition to hyper-visible inflamed os-cervix and vaginal wall by endoscopy and expression of NF-κβ P65.</p>","PeriodicalId":21035,"journal":{"name":"Reproduction in Domestic Animals","volume":"60 3","pages":"e70040"},"PeriodicalIF":1.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143664220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transvaginal Follicle Aspiration in Mares: A Description of Different Techniques and Comparison of Results Across Different OPU Clinics.","authors":"Juan Cuervo-Arango, Denis Necchi, Amber Clutton-Brock, Magdalena Profaska, James Crabtree, Anthony Claes","doi":"10.1111/rda.70043","DOIUrl":"https://doi.org/10.1111/rda.70043","url":null,"abstract":"<p><p>This retrospective clinical study describes different techniques for transvaginal follicle aspiration in mares and compares results from 5 different commercial ovum pick-up (OPU) clinics in which the same operator aspirated mares using different systems and equipment: Clinic 1 (n = 42 mares, two-operator OPU technique, double-lumen-echogenic-tip needle, and manual syringe-assisted flushing of follicles), Clinic 2 (n = 28 mares, single-operator-OPU-technique, double-lumen-echogenic-tip needle, infusion pump controlled by foot-pedal for follicle flushing), Clinic 3 (n = 18 mares, single-operator-OPU-technique, double-lumen-echogenic-tip needle, and manual syringe-assisted flushing of follicles), Clinic 4 (n = 24 mares, single-operator-OPU-technique, double-lumen-non-echogenic-tip needle, and manual syringe-assisted flushing of follicles), and Clinic 5 (n = 9 mares, aspirated as in Clinic 1). The ease of performing OPU (visibility of needle tip and difficulty to hold ovary, probe, and needle) and the mean number of recovered oocytes were compared between clinics. The mean number of recovered oocytes per mare and oocytes per follicle for clinics 1-5 were 11.9 ± 4.6 and 64%, 13.5 ± 6.5 and 53%, 12.3 ± 4.2 and 54%, 9.5 ± 3.3 and 51%, and 19.9 ± 8.2 and 64%, respectively. The combined recovered oocyte per aspirated follicle was 10% higher in clinics with a 2-operator technique (clinic 1 and 5, 63.63%) than in clinics with the single-operator technique (clinics 2-4, 53.32%). The mean number of recovered oocytes was numerically greater in the clinics using the echogenic needle tip (11.9, 13.5, 12.3, and 19.9 oocytes per mare, for clinics 1, 2, 3, and 5, respectively) than in the clinic using the non-echogenic needle tip; (9.5 oocytes per mare for clinic 4). The use of a plastic syringe or an infusion pump to flush follicles did not appear to affect the number of recovered oocytes or oocyte recovery rate (clinic 2 vs. 3). The left arm of the single operator (holding OPU probe and needle) experienced fatigue more frequently when mares were aspirated singly, than when the needle was managed by a second operator. In conclusion, the oocyte per follicle recovery was 10% lower in clinics using a single-operator-OPU-technique compared with clinics using a two-operator-technique.</p>","PeriodicalId":21035,"journal":{"name":"Reproduction in Domestic Animals","volume":"60 3","pages":"e70043"},"PeriodicalIF":1.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143586718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}