Animal Reproduction Science最新文献

{"title":"Ultrasonography for the detection of pregnancy and study of embryonic and fetal development in camels, buffaloes, and sheep: Techniques, equations, and limitations","authors":"Ahmed Ali ,&nbsp;Derar R. Derar ,&nbsp;Abdel-Razek Kh. Abdel-Razek","doi":"10.1016/j.anireprosci.2024.107566","DOIUrl":"10.1016/j.anireprosci.2024.107566","url":null,"abstract":"<div><p>New technologies for detecting pregnancy shortly after mating/insemination and identifying gestational age are essential for speeding up the reproductive cycle and ensuring high reproductive efficiency in livestock farming. Ultrasonography can successfully identify pregnancy and determine gestational age in many domestic animals. On the other hand, many herds of camel and buffalo and flocks of sheep are aware of the day of service, making it difficult to appropriately manage pregnant animals. This study provides a review of the literature on various techniques for ultrasonographically diagnosing pregnancy in camels, buffaloes, and sheep, focusing on the most appropriate times to use each technique, the earliest opportunity to diagnose pregnancy, and the possibility of using various parts of the fetus to create mathematical equations to determine gestational age. Some limitations of ultrasonography in pregnancy diagnosis were identified and significant pregnancy events in dromedaries were discussed, including left-horn and twin pregnancies. The data presented here will prove essential for researchers, farmers, and countries that rely heavily on these animals for providing meat, milk, cosmetics, and other animal products to enhance reproduction and production efficiency.</p></div>","PeriodicalId":7880,"journal":{"name":"Animal Reproduction Science","volume":"268 ","pages":"Article 107566"},"PeriodicalIF":2.2,"publicationDate":"2024-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141841445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oxylipin profiling analyses reveal that ω-3 PUFA is more susceptible to lipid oxidation in sheep testis under oxidative stress","authors":"Wanhong Li ,&nbsp;Ting Yao ,&nbsp;Xinyue Zhang ,&nbsp;Xiuxiu Weng ,&nbsp;Fadi Li ,&nbsp;Xiangpeng Yue","doi":"10.1016/j.anireprosci.2024.107567","DOIUrl":"10.1016/j.anireprosci.2024.107567","url":null,"abstract":"<div><p>Reactive oxygen species causes oxidative stress, which oxidizes polyunsaturated fatty acids (PUFAs) to form oxidative metabolites. Sertoli cell is an important cellular metabolism of PUFA in testicular cells, and it regulates the testis development and spermatogenesis. However, the oxylipins generated in testes with different developmental statuses are lacking. In this study, twelve 6-month-old Hu sheep were selected and divided into large testicular group (L) and the small testicular group (S) (n=6). UPLC–MS/MS was conducted to screen oxylipins in the testis, and the total oxylipin and ω-3 PUFA-derived oxylipin contents in the S group were higher. A total of 20 differential oxylipins between the two groups were screened. Among them, the contents of ω-3 PUFA, DHA-derived oxylipins were increased in the S group. The arachidonic acid-derived oxylipin was lower in the S group. The mRNA expression levels of genes related to oxylipin regulation (<em>AKR1B1</em>, <em>PTGER2</em>, and <em>PTGDS</em>) were higher in the S group (<em>P</em> &lt; 0.05). In <em>vitro</em>, 200 µM α-linolenic acid alleviated oxidative stress damage to Sertoli cells and improved cell viability by increasing the superoxide dismutase contents and mRNA expression levels of <em>GPX4</em> and <em>Bcl2</em>. These results indicate that ω-3 PUFA is more susceptible to lipid oxidation in the S group under oxidative stress, which might alleviate the damage of oxidative stress to testis. Moreover, ALA could stimulate the proliferation of Sertoli cells by increasing the capacity of antioxidants. This work may provide a theoretical basis for further studies on the antioxidant properties of the testis for Hu sheep.</p></div>","PeriodicalId":7880,"journal":{"name":"Animal Reproduction Science","volume":"268 ","pages":"Article 107567"},"PeriodicalIF":2.2,"publicationDate":"2024-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141787085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Brushing rams before and during electroejaculation improves sperm motility and kinetics with slight changes in stress biomarkers","authors":"Juan Carlos Orihuela ,&nbsp;Aline Freitas-de-Melo ,&nbsp;Livia Pinto-Santini ,&nbsp;Julia Giriboni ,&nbsp;Florencia Beracochea ,&nbsp;María Noel Viera ,&nbsp;Rodolfo Ungerfeld","doi":"10.1016/j.anireprosci.2024.107565","DOIUrl":"10.1016/j.anireprosci.2024.107565","url":null,"abstract":"<div><p>The aim of this study was to determine whether brushing rams before and during electroejaculation (EE) reduces their stress response and improves the characteristics of the ejaculate. A single person brushed each ram for 5 min daily, for 15 days, in an individual pen. Semen was collected from five rams brushed before and during EE by the same brusher, while the other five were electroejaculated without being brushed. The treatments were exchanged three days later, so semen was collected from all the rams with both treatments. Brushing increased mass motility (<em>P</em> = 0.05), and curvilinear (<em>P</em> = 0.001), linear (<em>P</em> = 0.02), and average path (<em>P</em> = 0.01) velocities of sperm, as well as the average amplitude of lateral displacement of the sperm head (<em>P</em> = 0.05), and tended to increase sperm concentration (<em>P</em> = 0.09). Brushing tended to reduce the cortisol concentration (<em>P</em> = 0.06) and the duration of head movements when 2 V pulse series V was applied (<em>P</em> = 0.1). Brushing increased creatine kinase concentration (<em>P</em> = 0.04) and tended to increase rectal (<em>P</em> = 0.06) and maximum eye surface temperatures (<em>P</em> = 0.1), total time, and number of electrical pulses administered (<em>P</em> = 0.07 for both variables), as well as the sum of pulses per voltage applied during EE (<em>P</em> = 0.06). In rams accustomed to being brushed by the same person, brushing them before and during EE improved semen quality, with slight changes in the stress responses.</p></div>","PeriodicalId":7880,"journal":{"name":"Animal Reproduction Science","volume":"268 ","pages":"Article 107565"},"PeriodicalIF":2.2,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141850765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of incorporating L-carnitine or Moringa oleifera leaves extract into semen diluent on cryosurvival and in vitro fertilization competence of buck sperm","authors":"Ahmed M. Kamel,&nbsp;Ibrahim S. Abd El-Hamid,&nbsp;Marwa Khalifa,&nbsp;Yousri M. Shaker,&nbsp;Sherif A. Rateb","doi":"10.1016/j.anireprosci.2024.107562","DOIUrl":"10.1016/j.anireprosci.2024.107562","url":null,"abstract":"<div><p>This study aimed at scrutinizing efficiency of incorporating L-carnitine or <em>M. oleifera</em> leaves extract into semen diluent on improving cryopreservation capacity and <em>in vitro</em> fertilization ability of buck spermatozoa. Ejaculates (<em>n</em>=48) were collected by an artificial vagina from six adult Damascus bucks twice weekly during the breeding season (September–October). Following initial evaluation, ejaculates of each collection session from the same bucks were pooled, diluted (1:10) with glycerolized (3 % glycerol, v/v) tris-citric acid egg yolk diluent and were split into three aliquots. The first aliquot served as control, whereas the second and third aliquots were supplemented with 4 μL/mL L-carnitine and 400 μL/mL moringa leaves extract (v/v), respectively. Thereafter, all specimens were processed for cryopreservation and were stored in liquid nitrogen (-196 °C) for 12 months before post-thaw sperm criteria were analyzed by a computer-assisted sperm analysis (CASA) system. Integrity of sperm DNA post thawing was visualized in all semen groups by fluorescence imaging, and <em>in vitro</em> fertilization ability of spermatozoa was also determined. Inclusion of L-carnitine or moringa leaves extract into the diluent improved (<em>P</em>&lt;0.05) post-thaw sperm physical, morphofunctional and kinematic attributes, whilst maintaining (<em>P</em>&lt;0.05) integrity of sperm DNA throughout the freezing and thawing cycle. Consequently, both supplemented groups yielded higher (<em>P</em>&lt;0.05) <em>in vitro</em> fertilization rates compared to control. These results accentuate the protective roles of these antioxidants on buck sperm against consequences of cryopreservation-induced oxidative stress, hence ameliorating post-thaw sperm quality and fertilization competence. This is crucial for successful application of AI and IVF in goat selective breeding programs.</p></div>","PeriodicalId":7880,"journal":{"name":"Animal Reproduction Science","volume":"268 ","pages":"Article 107562"},"PeriodicalIF":2.2,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141699182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transcriptomics reveals that NAD(P)H affects the development of the Zig-zag eel (Mastacembelus armatus ♀) × Spiny eel (Sinobdella sinensis ♂) hybrid offspring leading to low hatching rates","authors":"Di Sun ,&nbsp;Shaodan Wang ,&nbsp;Chong Wang ,&nbsp;Jixing Zou","doi":"10.1016/j.anireprosci.2024.107561","DOIUrl":"https://doi.org/10.1016/j.anireprosci.2024.107561","url":null,"abstract":"<div><p>Zig-zag eel (<em>Mastacembelus armatus</em> (2 n = 48)) and Spiny eel (<em>Sinobdella sinensis</em> (2 n = 48)) are two species of the Mastacembelidae family commonly found in southern China. Hybridization between the two has a very high deformity rate and a very low hatching rate. In order to investigate the reasons for this, the first hybridization between <em>M. armatus</em> and <em>S. sinensis</em> was carried out using artificial insemination, and the embryonic development of the hybrid offspring was examined using microphotography, and the malformations of the hybrid offspring were investigated by transcriptomics. The experiments showed that the average egg production was 4265.7 ± 322.94 (Mean ± SD), the average fertilization rate of hybrid offspring was 98.67 ± 0.58 % (Mean ± SD), the hatching rate was 12.06 ± 3.44 % (Mean ± SD), the deformity rate was 98.15 ± 3.21 % (Mean ± SD), and the embryonic development successively went through the five main stages of fertilized egg, egg cleavage, embryo formation, organogenesis, and exertion of membranes. Transcriptomics showed that the expression of NAD(P)H-related enzyme activity DEGs was increased, and many DEGs related to cell signaling molecule transmission and metabolic regulation are enriched in KEGG pathways, such as IL-17 signaling pathway, Osteoclast differentiation, TNF signaling pathway and MAPK signaling pathway. etc. The major types of DEGs corresponded to those coding for proteins. This study suggests that the high malformation rate in hybrid offspring may be caused by impaired synthesis of proteins during embryonic development.</p></div>","PeriodicalId":7880,"journal":{"name":"Animal Reproduction Science","volume":"268 ","pages":"Article 107561"},"PeriodicalIF":2.2,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141607754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In search of freezability predictors for feline spermatozoa – osmotic challenge tests and markers of sperm membrane structure","authors":"Sylwia Prochowska,&nbsp;Maria Eberhardt,&nbsp;Barbara Smalec,&nbsp;Wojciech Niżański","doi":"10.1016/j.anireprosci.2024.107563","DOIUrl":"10.1016/j.anireprosci.2024.107563","url":null,"abstract":"<div><p>Semen cryopreservation is a crucial part of assisted reproductive techniques (ART) in animals, and recently it is gaining more and more attention among cat breeders. Even if fresh semen quality is good, sometimes spermatozoa do not survive freezing. The freezability prediction was widely studied in many species, but not in the domestic cat. The aim of this study was to verify the usefulness of osmotic challenge tests and membrane structure markers (Yo-Pro 1 and Merocyanine 540) for the prediction of the quality of post-thawed feline semen. Semen was collected by urethral catheterization from 22 male cats. After a basic evaluation of semen, 20×10⁶ spermatozoa were cryopreserved; the rest were evaluated by flow cytometry for membrane integrity (SYBR-14/PI), acrosome status (lectin PNA/PI), mitochondrial potential (JC-1) and membrane stability (Yo-Pro 1/M540 staining). Hypo- and hyperosmotic challenge tests were also performed. The thawed samples were evaluated as fresh ones. The Pearson correlation between all parameters in fresh semen and all parameters in cryopreserved spermatozoa was assessed. Although some moderate correlations were found between the results of the osmotic tests and markers of sperm membrane stability (Yo-Pro 1 and Merocyanine 540) and post-thaw semen quality parameters, the predictive value of studied markers was rather weak – no cut-off values could be established and, based on regression models, they explained less than 40 % of variability in post-thaw quality. Our results confirm that cryodamage is a complex matter, in which many different factors play a role, affecting sperm motility and membrane integrity differently.</p></div>","PeriodicalId":7880,"journal":{"name":"Animal Reproduction Science","volume":"268 ","pages":"Article 107563"},"PeriodicalIF":2.2,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141714978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Production of bovine embryos by piezo-ICSI using capacitated spermatozoa selected by fluorescence-activated cell sorting (FACS-piezo-ICSI)","authors":"Macarena Castro ,&nbsp;Luis Aguila ,&nbsp;María Elena Arias ,&nbsp;Ricardo Felmer","doi":"10.1016/j.anireprosci.2024.107560","DOIUrl":"10.1016/j.anireprosci.2024.107560","url":null,"abstract":"<div><p>Intracytoplasmic sperm injection (ICSI) remains inefficient in cattle. One reason could lie in the injection of oocytes with sperm that have not undergone molecular changes associated with <em>in vivo</em> capacitation and fertilizing ability. This study aimed to enhance the efficiency of bovine intracytoplasmic sperm injection (piezo-ICSI) by employing fluorescent-activated cell sorting (FACS) to select the sperm population before injection based on capacitation markers. First, we evaluated the effects of incubating thawed sperm for 2 hours with different capacitating inductors: heparin, methyl-beta-cyclodextrin (MβCD), and dibutyryl cyclic AMP (dbcAMP), alone or in combinations in a basal capacitating (C) medium (Sp-TALP). Sperm capacitation and quality markers were evaluated by flow cytometry, revealing heparin as the most effective inducer of sperm capacitation changes. It, therefore, this treatment was chosen as the sperm pretreatment for FACS-piezo-ICSI. Two cell populations showing high capacitating levels (Heparin-HCL) and low capacitating levels (Heparin-LCL) of the markers associated with sperm capacitation i(Ca²⁺) levels and acrosome integrity were selected by FACS and used for sperm injection. Pronuclear formation was significantly higher when ICSI was performed with Heparin-HCL sperm than with Heparin-LCL and the control group (Heparin unsorted) groups (50 %, 10 %, and 20 %, respectively). Furthermore, injecting Heparin-HCL sperm resulted in a higher blastocyst rate (22.5 %) than Heparin-LCL (10 %) and the control group (15.2 %). In conclusion, heparin treatment effectively induced changes associated with sperm capacitation. The combination of Heparin-HCL treatment and FACS enabled precise selection of capacitated sperm before ICSI, enhancing the efficiency of this technology in the bovine species.</p></div>","PeriodicalId":7880,"journal":{"name":"Animal Reproduction Science","volume":"268 ","pages":"Article 107560"},"PeriodicalIF":2.2,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141639022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The influence of ghrelin agonist ipamorelin acetate on the hypothalamic-pituitary-testicular axis in a cichlid fish, Oreochromis mossambicus","authors":"Mallikarjun Gouda,&nbsp;C.B. Ganesh","doi":"10.1016/j.anireprosci.2024.107550","DOIUrl":"https://doi.org/10.1016/j.anireprosci.2024.107550","url":null,"abstract":"<div><p>Ghrelin, a peptide found in the brain and gut, is predicted to play a significant role in the control of various physiological systems in fish. The objective of this study was to examine the impact of ipamorelin acetate (IPA), a ghrelin agonist, on the reproductive axis of the tilapia <em>Oreochromis mossambicus</em>. The administration of either 5 or 30 µg of IPA for 21 days led to a significant and dose-dependent rise in food intake concomitant with a significant increase in the numbers of primary spermatocytes, secondary spermatocytes, and early spermatids compared to the control group. There was a significant rise in the number of late spermatids, as well as the areas of the lobule and lumen, in fish treated with 30 µg of IPA, compared to the control group. Moreover, there was no significant difference in the percentage of gonadotropin-releasing hormone (GnRH)-immunoreactive fibres in the hypothalamus and anterior pituitary gland across different groups. However, a significant elevation in the expression of androgen receptor protein was observed in fish treated with 30 µg of IPA. Furthermore, the concentrations of luteinizing hormone (LH) and 11-ketotestosterone (11-KT) in the serum of fish treated with either 5 or 30 µg of IPA were significantly elevated in comparison to the control group. Collectively, these findings suggest that the administration of ghrelin enhances the development of germ cells during the meiosis-I phase and that this effect might be mediated via the stimulation of 11-KT and androgen receptors at the testicular level and LH at the pituitary level in the tilapia.</p></div>","PeriodicalId":7880,"journal":{"name":"Animal Reproduction Science","volume":"268 ","pages":"Article 107550"},"PeriodicalIF":2.2,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141595133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High water temperature triggers early sexual maturation in the juvenile red spotted grouper Epinephelus akaara: Via regulation of reproduction-related hormones in the brain-pituitary-gonadal axis","authors":"Wengang Xu ,&nbsp;Kiyoshi Soyano ,&nbsp;Soichiro Manabe","doi":"10.1016/j.anireprosci.2024.107546","DOIUrl":"10.1016/j.anireprosci.2024.107546","url":null,"abstract":"<div><p>The red spotted grouper <em>Epinephelus akaara</em> is a marine species of economic importance and also at risk of extinction. This study investigated the effects of high water temperature on the growth and maturation of juvenile <em>E. akaara</em> females. From 160–420 days post-hatching (dph), the fish were maintained under natural water temperature (NT) and a constant high-water temperature (HT). From 240 dph, both the total length and body weight in the HT group were greater than in NT group. After 360 dph, the gonadosomatic index was also increased in the HT group compared to NT group. Mature oocytes were only observed in the HT group at 330, 360, and 390 dph. Both <em>kiss1</em> and <em>kiss2</em> levels increased at 240 and 270 dph in both groups; however, they were greater in the HT group at 240 dph. Similarly, <em>gpr54</em> levels after 360 dph were greater in the HT group, suggesting that kisspeptin is related to maturation via its receptor <em>gpr54</em>. Levels of <em>fshβ</em> and <em>lhβ</em> were greater in the HT group after 360 dph. Estradiol-17β (E₂) levels after 160 dph (except 300 dph) were greater in the HT group than in the NT group, suggesting that the higher E₂ levels trigger maturation, and is related to increased <em>fshβ</em> and <em>lhβ</em>. This study provides evidence that high water temperature is effective in accelerating growth and triggering early maturation of juvenile <em>E. akaara</em>, via regulating <em>gpr54</em>, <em>fshβ</em>, <em>lhβ</em>, and E₂ levels.</p></div>","PeriodicalId":7880,"journal":{"name":"Animal Reproduction Science","volume":"268 ","pages":"Article 107546"},"PeriodicalIF":2.2,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141533419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In mares resistant to endometrial infection, periovulatory treatment with ecbolic drugs does not influence uterine clearance or luteal development","authors":"Younis Khan ,&nbsp;Amr El-Shalofy ,&nbsp;Martim Kaps ,&nbsp;Camille Gautier ,&nbsp;Christine Aurich","doi":"10.1016/j.anireprosci.2024.107548","DOIUrl":"10.1016/j.anireprosci.2024.107548","url":null,"abstract":"<div><p>We aimed to determine associations between experimentally impaired uterine clearance or treatment with ecbolic drugs on luteal development in estrous mares after insemination. In a crossover design, eight mares were treated with saline (CON), clenbuterol (CLEN), oxytocin (OXY) and carbetocin (CARB) from the day of first insemination until 2 days after ovulation. Between treatments, the mares rested for one cycle. Estrous mares were examined for the presence of free intrauterine fluid by transrectal ultrasound. Endometrial swabs for cytology and bacteriology were collected on days 1 and 14. Blood samples were collected daily before AI until day 14 after ovulation for determination of progesterone and PGF_2α metabolites (PGFM). Differences between treatments were compared by a general linear model for repeated measures (SPSS 29). One mare was excluded because of a uterine infection in the control cycle. In all other mares, only minor amounts of free intrauterine fluid were present after insemination and decreased over time (<em>P</em>&lt;0.05) with no treatment x time interaction. There was no effect of treatment on polymorphonucleated cells (PMN) in endometrial cytology after ovulation or PGFM secretion. Progesterone release from day 1–14 as well as pregnancy rate and conceptus size on day 14 was not influenced by treatment. In conclusion, treatment with clenbuterol does not impair uterine clearance in estrous mares resistant to endometritis. Repeated injection of the oxytocin analogue carbetocin during the early postovulatory period is not detrimental to corpus luteum function and can be recommended to enhance uterine clearance.</p></div>","PeriodicalId":7880,"journal":{"name":"Animal Reproduction Science","volume":"267 ","pages":"Article 107548"},"PeriodicalIF":2.2,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0378432024001398/pdfft?md5=090945e53fdbde205a160b4f7b7d45f4&pid=1-s2.0-S0378432024001398-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141496896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}