Theriogenology最新文献

{"title":"Effectiveness of intraglandular allogeneic mesenchymal stem cell administration for treating chronic vesicular adenitis in bulls","authors":"Neimar Correa Severo ,&nbsp;Teresinha Inês de Assumpção ,&nbsp;Maurício Antônio Silva Peixer ,&nbsp;Marcelo da Cunha Xavier ,&nbsp;Patricia Furtado Malard ,&nbsp;Hilana dos Santos Sena Brunel ,&nbsp;Renata Lançoni","doi":"10.1016/j.theriogenology.2025.117419","DOIUrl":"10.1016/j.theriogenology.2025.117419","url":null,"abstract":"<div><div>This study aimed to evaluate the effects of the application of allogeneic mesenchymal stem cells (MSCs) bilaterally and intraglandularly in the vesicular glands of bulls affected by seminal vesiculitis. Twelve bulls that presented chronic vesiculitis with two or more recurrences were selected at Semen Collection and Processing Centres, based on the presence of pus in the semen, leukocytes on the motility and vigour evaluation slide, reactive to the California Mastitis Test - CMT (one cross or more) and the presence of leukocytes on a slide stained by Diff Quik staining with more than 5 polymorphonuclear cells (PMN) per field. Ultrasound examination of the vesicular glands was performed, and the clinical signs were definitive for the diagnosis. The proposed method of the intraglandular injection of MSCs involved application through the ischiorectal fossa with a long needle measuring 30–35 cm and a guide measuring 25–30 cm in length directly into the affected vesicular glands. The MSCs were cultured and frozen in the Bio Cell Cellular Therapy® laboratory (Brasilia, Brazil) and prepared by washing and centrifugation for intraglandular injection on the day of application. In total, 3x10⁶ MSCs were injected into each vesicular gland. Data were evaluated for normality of residuals using the Shapiro-Wilk test. When the normality of the test was significant (P &lt; 0.05), the data were transformed or outliers were removed and reevaluated. The “T-Test” was applied to identify statistical differences between variables before and after treatment. The probability of P ≤ 0.05 was considered a significant difference. Data were presented as the mean ± standard error of the mean (S.E.M.). Improvements were observed in the initial percent motility from 60.09 ± 4.8 to 69.89 ± 4.6 (P &lt; 0.05), as well as in the post-thawing percent motility from 26.26 ± 6.77 to 42.5 ± 5 0.99 (P &lt; 0.05). The number of doses produced increased significantly after treatment with MSCs, from 95.61 ± 23.31 units to 337.84 ± 67.75 units (P &lt; 0.05) per ejaculate. The number of leukocytes observed per field decreased from 5.83 ± 0.48 to zero, demonstrating the recovery of the inflamed vesicular glands. Based on the results presented, it was concluded that the application of 3x10⁶ MSCs in the vesicular glands of bulls with vesiculitis is safe and efficient, as it improved several parameters evaluated in this research, mainly the production of semen doses per ejaculate.</div></div>","PeriodicalId":23131,"journal":{"name":"Theriogenology","volume":"241 ","pages":"Article 117419"},"PeriodicalIF":2.4,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143783174","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":"Effect of pre-freeze sperm concentration, freezing extender, and epididymal flushing technique on post-thaw quality of cryopreserved epididymal stallion sperm","authors":"Sheila G. Spacek ,&nbsp;Camilo Hernández-Avilés,&nbsp;Luisa Ramírez-Agámez,&nbsp;Mariah Pearson,&nbsp;Charles C. Love","doi":"10.1016/j.theriogenology.2025.117418","DOIUrl":"10.1016/j.theriogenology.2025.117418","url":null,"abstract":"<div><div>Cryopreservation of stallion epididymal sperm has become a common clinical procedure after routine castration, euthanasia, or acute death. Unique features of epididymal sperm compared to ejaculated sperm include the requirement to remove sperm from the <em>cauda epididymis</em>, lack of exposure to seminal plasma, and potential recovery of large sperm numbers. In this study, the effect of the flushing technique (Extender (INRA) vs. AIR), freezing extender (LE, CMLE, MFR5, CFR5, or BOTU), and the concentration at which sperm are cryopreserved (200, 400, or 800 × 10⁶ sperm/mL) on post-thaw epididymal sperm quality were studied. More total sperm were recovered when the <em>cauda epididymides</em> were flushed with INRA (14 × 10⁹) compared to AIR (10 × 10⁹). Epididymal sperm cryopreserved in BOTU and CMLE yielded higher post-thaw total and progressive motility than LE, MFR5, and CFR5 (P &lt; 0.05); BOTU, MFR5, and CFR5 yielded higher post-thaw viable/acrosome-intact sperm than CMLE or LE (P &lt; 0.05); CMLE, CFR5, and BOTU yielded higher post-thaw curvilinear velocity than LE or MFR5 (P &lt; 0.05); an effect of extender on sperm DNA damage (COMP_αt) was not observed (P &gt; 0.05). Overall, similar post-thaw epididymal sperm quality parameters were observed among different cryopreserved sperm concentrations (P &lt; 0.05). This study provides evidence of some factors that can affect the post-thaw quality of epididymal sperm from stallions.</div></div>","PeriodicalId":23131,"journal":{"name":"Theriogenology","volume":"241 ","pages":"Article 117418"},"PeriodicalIF":2.4,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143791027","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":"Short- and long-term effects of uterine disease on oocyte developmental capacity in postpartum dairy cows","authors":"M.O. Caldeira ,&nbsp;K.S. McDonald ,&nbsp;E.S.M. Martinez ,&nbsp;J.G.N. Moraes ,&nbsp;I. Sellmer Ramos ,&nbsp;S.E. Poock ,&nbsp;M.S. Ortega ,&nbsp;M.C. Lucy","doi":"10.1016/j.theriogenology.2025.117413","DOIUrl":"10.1016/j.theriogenology.2025.117413","url":null,"abstract":"<div><div>The hypothesis was that early postpartum uterine disease would reduce the developmental capacity of oocytes thus contributing to the reduced fertility of dairy cows with uterine disease. Dairy cows were diagnosed healthy or with metritis at 7–10 d postpartum. The reproductive tract was collected at approximately 1 mo (Exp. 1) or approximately 80 or 165 d (Exp. 2) postpartum for the collection of cumulus-oocyte complexes (COC). The COC were matured, co-incubated with sperm for fertilization, and cultured to the blastocyst stage (8 d) in vitro. For Exp.1, the disease diagnosis (healthy or metritis) did not affect the number of collected COC or the subsequent embryo development to the blastocyst stage. The presence of purulent material in the uterine lumen (endometritis) at time of oocyte collection, however, was associated with a reduced cleavage rate evaluated 3 d following fertilization. For Exp. 2, there was no effect of disease diagnosis (healthy or metritis) on the number of COC or their subsequent development. Reduced cleavage rates were observed in COC retrieved from cows slaughtered at 80 d postpartum, but not at 165 d postpartum, and this reduction was associated with a vaginal microbiome indicative of uterine disease at 4–5 wk postpartum. Regression analyses that included plasma haptoglobin or energy metabolite concentrations or uterine bacterial genera abundance did not explain a large percentage of the variation in oocyte development in vitro. We conclude that there is an effect of uterine disease at one month postpartum on the oocyte and its capacity for development (Exp. 1) and this effect may be present at 80 d postpartum (Exp. 2). In later postpartum cows (165 d postpartum; Exp. 2) there was no effect of uterine disease on in vitro oocyte development.</div></div>","PeriodicalId":23131,"journal":{"name":"Theriogenology","volume":"240 ","pages":"Article 117413"},"PeriodicalIF":2.4,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747251","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":"Cryopreservation of sturgeon egg mitochondria and their replacement in germline: A novel strategy for maternal genetic preservation in sturgeons","authors":"Linan Gao,&nbsp;Roman Franěk,&nbsp;Martin Pšenička","doi":"10.1016/j.theriogenology.2025.117414","DOIUrl":"10.1016/j.theriogenology.2025.117414","url":null,"abstract":"<div><div>Nearly all sturgeon species are critically endangered, necessitating the development of innovative approaches to preserve their genetic diversity and support population recovery. Unlike sperm, the cryopreservation of fish eggs or embryos remains technically unscalable because of the inherent structural and compositional barriers. Mitochondria are abundant in germ plasm and indispensable in the formation of primordial germ cells (PGCs). Transplanting isolated mitochondria into the vegetal pole of sturgeon embryos, where germ plasm is located, represents a promising conservation strategy. The transplanted mitochondria integrate into the germ plasm and are subsequently incorporated into the germline. Considering seasonality and long generation intervals of sturgeon reproduction, a reliable method for long-term storage of sturgeon egg mitochondria would be advantageous. This study optimized the cryopreservation of sturgeon egg-derived mitochondria, with subsequent validation of mitochondria structural and functional integrity. Various concentrations of dimethyl sulfoxide (DMSO), glycerol, and bovine serum albumin (BSA), combined with different freezing protocols were tested. Mitochondria functionality was assessed through four keys indicators: adenosine triphosphate synthesis, reactive oxygen species production, mitochondrial membrane potential, and integrity. For the first time, we demonstrated that sturgeon egg mitochondria can be successfully cryopreserved, recovered using transplantation and incorporated into the germline. Therefore, we restored maternal germplasm in sturgeon embryos. This work establishes a vital technological advance for conservation biology, offering an alternative approach to preserving and restoring maternal genetic information, which is currently unachievable through other methods in fish. Future research can leverage mitochondrial applications to advance germline preservation, surrogate reproduction, fertility enhancement, and reproductive biotechnology in aquaculture species.</div></div>","PeriodicalId":23131,"journal":{"name":"Theriogenology","volume":"240 ","pages":"Article 117414"},"PeriodicalIF":2.4,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747185","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":"Intrauterine growth restriction in newborn piglets associated with piglet characteristics, colostrum intake, litter size and parity number in prolific sows","authors":"Tanwarat Chaiyapatmaetee ,&nbsp;Natrada Saenghinghoy ,&nbsp;Pitchayapak Charuchinda ,&nbsp;Thussapong Wichathippayananon ,&nbsp;Jakavat Ruampatana ,&nbsp;Yosua Kristian Adi ,&nbsp;Preechaphon Taechamaeteekul ,&nbsp;Padet Tummaruk","doi":"10.1016/j.theriogenology.2025.117416","DOIUrl":"10.1016/j.theriogenology.2025.117416","url":null,"abstract":"<div><div>The genetic selection of highly prolific sows has increased the number of fetuses within the uterus, directly affecting piglet quality due to limited placental space. This results in placental insufficiency and fetal intrauterine growth restriction (IUGR). This study aimed to investigate the incidence of IUGR in newborn piglets within a commercial swine herd under tropical conditions and to examine its association with piglet characteristics, birth order, litter size, sow parity, colostrum intake, and mortality rate during the first 24 h of life. The experiment was conducted in a commercial swine herd in Thailand. Data were collected from 114 litters of French Landrace × Yorkshire crossbred sows. Immediately after birth, the degree of IUGR was determined in 1868 piglets, comprising 1743 live-born and 125 stillborn piglets. Sows were categorized into four groups based on parity number: 1 (n = 28), 2 (n = 34), 3–5 (n = 33), and 6–8 (n = 19). Litters were further classified by total litter size into three categories: 7–14 (n = 18), 15–19 (n = 51), and ≥20 piglets (n = 45). On the day of parturition, IUGR was visually assessed in both live-born and stillborn piglets. Various farrowing and piglet parameters were recorded, including farrowing duration and litter traits. Birth weight was measured before and after colostrum ingestion, and individual colostrum intake was calculated. The incidence of IUGR in newborn piglets was 16.2 % (302/1868 piglets), with moderate and severe IUGR observed in 10.8 % and 5.4 % of piglets, respectively. The percentage of IUGR piglets in litters with 7–14 piglets (8.5 %) was lower than in litters with 15–19 piglets (17.1 %, <em>P</em> = 0.008) and ≥20 piglets (17.2 %, <em>P</em> = 0.005). IUGR piglets exhibited significantly lower birth weights (832 ± 28.6 g vs. 1274 ± 16.8 g, <em>P</em> &lt; 0.001) compared to normal piglets. They also consumed less colostrum (257.1 ± 14.2 g vs. 414.3 ± 7.4 g, <em>P</em> &lt; 0.001) and had a higher percentage of individuals with insufficient colostrum intake (&lt;300 g) (77.3 % vs. 27.6 %, <em>P</em> &lt; 0.001). At 24 h postpartum, IUGR piglets exhibited lower rectal temperatures (37.7 ± 0.1 vs. 38.1 ± 0.1 °C, <em>P</em> &lt; 0.001) compared to normal piglets. Additionally, IUGR piglets experienced a higher mortality rate within the first 24 h of life compared to normal piglets (18.5 % vs. 6.1 %, <em>P</em> &lt; 0.001). In conclusion, the results demonstrate that IUGR piglets exhibit lower birth weights, reduced colostrum intake, and poorer thermoregulation. These factors contribute to the higher mortality rate observed in IUGR piglets compared to their normal counterparts. Moreover, the proportion of IUGR piglets increases with larger litter sizes, emphasizing the impact of uterine crowding. This study underscores the importance of managing sow productivity to minimize the prevalence of IUGR and improve piglet survival and welfare.</div></div>","PeriodicalId":23131,"journal":{"name":"Theriogenology","volume":"240 ","pages":"Article 117416"},"PeriodicalIF":2.4,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747250","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":"Effect of glutathione addition on vitrification of ovine oocytes","authors":"Jingyu Ren ,&nbsp;Gang Liu ,&nbsp;Huan Cui ,&nbsp;Xubin Dong ,&nbsp;Shuangyu Mao ,&nbsp;Yongbin Liu ,&nbsp;Yanfeng Dai","doi":"10.1016/j.theriogenology.2025.117412","DOIUrl":"10.1016/j.theriogenology.2025.117412","url":null,"abstract":"<div><div>The exogenous antioxidants are commonly employed to mitigate vitrification-induced oxidative damage. Glutathione (GSH), a vital antioxidant, plays a significant role in scavenging free radicals, providing antioxidant protection, and maintaining cellular integrity. This study aimed to investigate the effects of GSH supplementation on the vitrification of ovine oocytes. To identify the optimal concentration of exogenous GSH supplementation, the impacts of 2 mM, 4 mM, and 8 mM GSH on the survival and fragmentation of oocytes were evaluated after vitrification. In addition, immunofluorescence (IF) staining was employed to evaluate spindle morphology, chromosome distribution, cortical granule distribution, mitochondrial function, and reactive oxygen species (ROS) levels. The levels of ATP and NADPH, along with the ratio of GSH/GSSH, were also examined. Additionally, evaluations of <em>in vitro</em> fertilization were carried out. The results of oocyte survival rates and fragmentation rates identified that the addition of 4 mM GSH to the vitrification solution was the optimal concentration. The assessment of spindle morphology, chromosome distribution, cortical granule distribution, mitochondrial function, ROS production, ATP activity, and NADPH levels, as well as the GSH/GSSH ratio, confirm the beneficial effect of GSH supplementation against the vitrification-induced oxidative damage. Lastly, incorporating GSH into the vitrification process enhanced the developmental potential of oocytes, resulting in higher cleavage rates, increased blastocyst rates, and improved quality of blastocysts. Overall, this research uncovered the mechanisms through which GSH mitigates the oxidative damage induced by vitrification, thereby leading to the optimization of the vitrification technique for ovine oocytes.</div></div>","PeriodicalId":23131,"journal":{"name":"Theriogenology","volume":"240 ","pages":"Article 117412"},"PeriodicalIF":2.4,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747249","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":"Lipid and fatty acid profile in neat and collagenase-treated llama sperm","authors":"Mariana Lucía Bertuzzi ,&nbsp;Jessica Mariela Luquez ,&nbsp;Andrea Romina di Fonzo ,&nbsp;Gerardo Martín Oresti ,&nbsp;María Ignacia Carretero","doi":"10.1016/j.theriogenology.2025.117411","DOIUrl":"10.1016/j.theriogenology.2025.117411","url":null,"abstract":"<div><div>The lipid composition of spermatozoa plasma membranes is crucial for both fertilization and cryopreservation techniques. Llama seminal plasma has unique rheological characteristics and proteolytic enzymes have been used to enhance semen handling. The purpose of this study was to evaluate the plasma membrane lipid composition of llama sperm from neat semen and to compare it with sperm from neat semen incubated with collagenase, as an attempt to determine the possible involvement of collagenase over membrane lipids. Also, we investigate the differences in lipid composition of sperm collected in summer <em>versus</em> winter, and between young and adult animals. Fifty-two ejaculates from six llamas were obtained and routine seminal parameters were evaluated. Cholesterol (Chol), phospholipids (PL), Chol/PL ratio, fatty acid (FA) groups, individual FA, and PL classes were evaluated in sperm from neat semen and after incubation with collagenase. No significant differences were found in Chol, PL, Chol/PL ratio, FA, and PL classes between neat semen spermatozoa and those incubated with collagenase. When comparing these same parameters by season, no significant differences were observed. Younger males showed significantly lower PL content in sperm from neat semen, with a trend of higher Chol, a higher Chol/PL ratio, and lower polyunsaturated FA percentages compared to adult males. In conclusion, this study identified the lipid composition of neat llama spermatozoa, showing that collagenase treatment does not alter it. While no seasonal differences were observed, significant age-related differences in sperm lipid composition were found. The findings provide insights into llama sperm lipids, potentially relevant for cryopreservation.</div></div>","PeriodicalId":23131,"journal":{"name":"Theriogenology","volume":"241 ","pages":"Article 117411"},"PeriodicalIF":2.4,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143783175","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":"Ultrasonographic and elastographic evaluation of the canine cervix across oestrous cycle stages","authors":"Claudia Bracco ,&nbsp;Sandra Goericke-Pesch ,&nbsp;Alberto Contri ,&nbsp;Alessandro Piccinini ,&nbsp;Alessia Gloria","doi":"10.1016/j.theriogenology.2025.117410","DOIUrl":"10.1016/j.theriogenology.2025.117410","url":null,"abstract":"<div><div>This study evaluated B-mode ultrasonography and ultrasound elastography (UEl) for detecting structural and consistency changes in the canine cervix across the oestrous cycle, as the use of ultrasonographic techniques for this purpose remains underexplored. The present study aims to assess cervical features via ultrasound, acknowledging the critical role of the cervix in the canine oestrus cycle. Thirty-five bitches were evaluated during pro-oestrus, pre-ovulatory oestrus, peri-ovulatory oestrus, dioestrus and anoestrus. Progesterone levels, clinical signs, vaginoscopy and cytology were used to define the oestrous cycle phase. Cervical length, diameter, and the elastographic index (ElI) were measured, and the elastographic ratio (ElR) was calculated to compare cervical stiffness to the surrounding tissue. Cervical length and diameter values were observed to be higher during the pre-ovulatory and peri-ovulatory phases of oestrus (p &lt; 0.05). ElI values in anoestrus were similar to dioestrus and significantly higher than pro-oestrus and pre-ovulatory oestrus (p &lt; 0.05), reflecting greater cervical stiffness in anoestrus and dioestrus, while pro-oestrus and pre-ovulatory phases showed softer tissues. These findings underscore the utility of elastography in quantifying cervical tissue consistency and its correlation with hormonal influences, providing a novel diagnostic perspective for a more comprehensive understanding of reproductive health.</div></div>","PeriodicalId":23131,"journal":{"name":"Theriogenology","volume":"240 ","pages":"Article 117410"},"PeriodicalIF":2.4,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738134","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":"Improved reproductive performance and economic outcomes from use of a modified 5-day Cosynch program in pasture-based dairy heifers","authors":"Peter J. Aitken ,&nbsp;Andrew Hodge ,&nbsp;Gregory P. Chambers ,&nbsp;Laura H. Beasley","doi":"10.1016/j.theriogenology.2025.117403","DOIUrl":"10.1016/j.theriogenology.2025.117403","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The primary objective of this study was to evaluate reproductive performance in dairy heifers submitted to fixed-time artificial insemination (FTAI) following a modified 5-day Cosynch program (&lt;strong&gt;m5dC&lt;/strong&gt;) compared to a 7-day Cosynch program (&lt;strong&gt;7&lt;/strong&gt;&lt;strong&gt;dC&lt;/strong&gt;). Additionally, the study examined the economic impacts of treating heifers with the &lt;strong&gt;m5dC&lt;/strong&gt; program compared to the &lt;strong&gt;7&lt;/strong&gt;&lt;strong&gt;dC&lt;/strong&gt; program, and the effect of pre-synchronization with prostaglandin (PG) on serum progesterone (P4) concentration.&lt;/div&gt;&lt;div&gt;At the start of the breeding season, maiden heifers (n = 565) from four New Zealand dairy farms were randomly allocated to one of two synchronization programs: 1) &lt;strong&gt;m5dC&lt;/strong&gt; (n = 283), 500 μg cloprostenol administered on Study Day −10, 100 μg gonadotrophin-releasing hormone (GnRH) on Study Day −8, 500 μg cloprostenol on Study Day −3, 500 μg cloprostenol on Study Day −2, 100 μg GnRH concurrent with FTAI on Study Day 0, and insertion of an intravaginal P4-releasing insert (CIDR) for 5 days commencing on Study Day −8; 2) &lt;strong&gt;7&lt;/strong&gt;&lt;strong&gt;dC&lt;/strong&gt; (n = 282), 100 μg GnRH administered on Study Day −10, 500 μg cloprostenol on Study Day −3, 100 μg GnRH concurrent with FTAI on Study Day −1 and insertion of a CIDR for 7 days commencing on Study Day −10. Heifers were then mated either by a combination of insemination to observed heat and natural mating or by natural mating alone, depending on farm management policy, for a total mating period of up to 10 weeks.&lt;/div&gt;&lt;div&gt;Serum P4 concentration was measured in a subset of heifers (n = 34) selected randomly from both treatment groups at the time of CIDR insertion; geometric mean values were lower for &lt;strong&gt;m5dC&lt;/strong&gt; heifers (1.35 ng/ml (95 % CI 1.04–1.76)) than &lt;strong&gt;7&lt;/strong&gt;&lt;strong&gt;dC&lt;/strong&gt; heifers (2.95 ng/ml (95 % CI 1.79–4.84)). Conception rate (CR) to FTAI and subsequent reproductive performance were evaluated based on ultrasound pregnancy diagnosis carried out between Study Days 95 and 123. Performance was significantly improved for &lt;strong&gt;m5dC&lt;/strong&gt; heifers compared to &lt;strong&gt;7&lt;/strong&gt;&lt;strong&gt;dC&lt;/strong&gt; heifers for both CR to FTAI (62.0 % vs. 45.4 %, p = 0.0007) and 6-week pregnancy rate (87.6 % vs. 74.4 %, p = 0.0002). Mean interval from FTAI to conception was shorter for &lt;strong&gt;m5dC&lt;/strong&gt; heifers (15.1 days) compared to &lt;strong&gt;7&lt;/strong&gt;&lt;strong&gt;dC&lt;/strong&gt; heifers (25.0 days). A difference in final pregnancy rate was not detected between treatment groups (p = 0.18). A partial budget was constructed to estimate the economic return of synchronizing heifers with the &lt;strong&gt;m5dC&lt;/strong&gt; program compared to the &lt;strong&gt;7&lt;/strong&gt;&lt;strong&gt;dC&lt;/strong&gt; program, producing a net return of NZ$72.29 per heifer. Synchronization of dairy heifers with an &lt;strong&gt;m5dC&lt;/strong&gt; program resulted in superior reproductive performance at FTAI and following 6 weeks of mating compared to the &lt;s","PeriodicalId":23131,"journal":{"name":"Theriogenology","volume":"240 ","pages":"Article 117403"},"PeriodicalIF":2.4,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738133","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":"Effect of in vivo and in vitro heat stress on DNA methylation and DNA hydroxymethylation of bovine oocytes and early embryos","authors":"F.A. Diaz,&nbsp;E.J. Gutierrez,&nbsp;B.A. Foster,&nbsp;P.T. Hardin,&nbsp;K.R. Bondioli","doi":"10.1016/j.theriogenology.2025.117400","DOIUrl":"10.1016/j.theriogenology.2025.117400","url":null,"abstract":"<div><div>In the bovine commercial industry, reduced reproductive performance in response to heat stress is one of the main factors causing economic losses. Several studies have shown that heat stress negatively affects oocytes and embryos at the morphological, biochemical, transcriptional, and developmental levels. Yet, there is limited information on the effect of heat stress on the epigenetic modifications of bovine oocytes and embryos. Therefore, the objective of this study was to evaluate the effect of in vivo and in vitro heat stress on the developmental competence, DNA methylation, and DNA hydroxymethylation of bovine oocytes and early embryos. Oocytes were collected through ovum pick-up from non-lactating, non-pregnant <em>Bos taurus</em> beef cows in February and August under Louisiana environmental conditions. The treatments evaluated were: in vivo heat stress (oocytes collected in August), in vitro heat stress (oocytes collected in February and subjected to in vitro heat stress), and control (oocytes collected in February and not subjected to in vitro heat stress). Developmental rates, DNA methylation and DNA hydroxymethylation of metaphase II oocytes (MII), 2-pronucleus embryos (2 PN) and 2–4 cell embryos were evaluated. Global DNA methylation and DNA hydroxymethylation were evaluated through fluorescence immunostaining. No differences between treatments was detected in developmental rates of MII oocytes, 2 PN embryos and 2–4 cell embryos. Similarly, no differences between treatments was detected in global DNA methylation and DNA hydroxymethylation of MII oocytes, 2 PN embryos, and 2–4 cell embryos. Importantly, no differences in global DNA methylation or DNA hydroxymethylation of paternal or maternal pronucleus was detected, indicating that the demethylation process during the 2 PN embryo stage was not altered at the global level. The results of our study showed that under our experimental conditions, in vivo and in vitro heat stress did not affect developmental rates, DNA methylation and DNA hydroxymethylation of MII oocytes and early embryos produced from oocytes obtained from non-lactating, non-pregnant <em>Bos taurus</em> beef cows.</div></div>","PeriodicalId":23131,"journal":{"name":"Theriogenology","volume":"240 ","pages":"Article 117400"},"PeriodicalIF":2.4,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143760946","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}