Animal Reproduction最新文献

{"title":"Follicular dynamics and hormonal profile in Prepubertal nelore and Murrah heifers subjected to fixed-time artificial insemination (FTAI).","authors":"Isabella de Oliveira Bêta, Larissa de Paiva Nunes Gonçalves, Aline Pacheco, Yana Eliza Feitosa de Almeida, Alisson Jordão Prado, Pietro Sampaio Baruselli, Kedson Alessandri Lobo Neves, Antonio Humberto Hamad Minervino","doi":"10.1590/1984-3143-AR2025-0010","DOIUrl":"10.1590/1984-3143-AR2025-0010","url":null,"abstract":"<p><p>We aimed to evaluate puberty induction, follicular dynamics, and hormonal profiles of progesterone (P4) and estradiol (E2) in prepubertal Nelore and Murrah heifers subjected to synchronization for fixed-time artificial insemination (FTAI). Six Nelore heifers (14 to 17 months old; 320 to 350 kg) and six Murrah heifers (14 to 17 months old; 422 to 523 kg) confirmed as prepubertal by ultrasonography due to the absence of a corpus luteum were used. The protocol included an intravaginal P4 device (0.5 mg) on D0, along with the administration of estradiol benzoate (EB) and prostaglandin F2α. In Nelore, the device was removed on D7, followed by the administration of estradiol cypionate, prostaglandin F2α, and eCG, with insemination occurring 48-56 hours after intravaginal device removal (D9). In Murrah, the device was removed on D9, followed by prostaglandin F2α and Ecg administration, with insemination on D12 after GnRH administration (D11). Blood samples were collected (Nelore: D7 and D9; Murrah: D9 and D12) to measure hormone levels, and ultrasonography monitored follicular dynamics and ovulation. The ovulatory follicle diameter was 7.83 ± 2.25 mm (Nelore) and 7.7 ± 1.63 mm (Murrah), with no significant differences (P > 0.05). The dominant follicle diameter at P4 device removal was 6.5 ± 1.59 mm (Nelore) and 6.9 ± 4.97 mm (Murrah). The mean P4 levels were 0.76 ng/mL (Nelore) and 1.42 ng/mL (Murrah) at P4 device removal, and 1.00 ng/mL and 0.52 ng/mL at the moment of FTAI. The mean E2 levels were 9.28 pg/mL (Nelore) and 26.75 pg/mL (Murrah) at the P4 device removal, and 11.20 pg/mL and 11.59 pg/mL at the moment of FTAI. Ovulation rates were 100% in Nelore and 50% in Murrah. These results highlight the importance of tailoring FTAI protocols to the specific reproductive characteristics of each breed.</p>","PeriodicalId":7889,"journal":{"name":"Animal Reproduction","volume":"23 2","pages":"e20250010"},"PeriodicalIF":2.3,"publicationDate":"2026-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13142083/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147832062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emerging imaging modalities for the diagnosis of malignant lesions of the male reproductive tract in companion animals.","authors":"Diego Rodrigues Gomes, Anna Carolina Mazeto Ercolin, Gabriela Castro Lopes Evangelista, Felipe Farias Pereira da Câmara Barros, Camila Silveira Stanquini, Camila Debastiani, Fredderico Garcia, Marcus Antônio Rossi Feliciano","doi":"10.1590/1984-3143-AR2025-0124","DOIUrl":"10.1590/1984-3143-AR2025-0124","url":null,"abstract":"<p><p>Understanding diseases that affect the male reproductive system of dogs and cats is important for improving their health and quality of life. Imaging techniques, such as ultrasound and X-rays, play a fundamental role in the evaluation of this system. They help veterinarians detect problems in the testicles, prostate, and other reproductive organs of dogs and cats. In recent years, advanced ultrasound methods, such as Doppler, elastography, and contrast-enhanced ultrasound, have become more accessible and allow earlier and more accurate diagnosis. Although definitive diagnosis of neoplastic lesions depends on cytological or histopathological examinations, radiography and advanced ultrasonography contribute significantly to early detection and malignancy characterization. This literature review explores the main imaging techniques used in the investigation of malignant lesions in the male reproductive tract of dogs and cats, namely radiography, B-mode and Doppler ultrasonography, elastography, and contrast-enhanced ultrasonography (CEUS). The goal is to help veterinarians make better decisions and improve care for their patients. The integration of these modalities has become well established in human medicine and shows growing applicability in veterinary practice, allowing for real-time, non-invasive assessment of the testes, prostate, penis, and scrotal structures. The compiled data highlight the potential of combining different imaging modalities to improve diagnostic accuracy and provide clinical and surgical support in the management of malignant lesions affecting the male reproductive tract in dogs and cats.</p>","PeriodicalId":7889,"journal":{"name":"Animal Reproduction","volume":"23 2","pages":"e20250124"},"PeriodicalIF":2.3,"publicationDate":"2026-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13075779/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147687870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative evaluation of sperm parameters in Italian (<i>Apis mellifera ligustica</i>) and Africanized (<i>Apis mellifera</i>) honeybee drones from the Caatinga biome.","authors":"Lilian Leal Dantas, Andréia Maria da Silva, Leandro Alves da Silva, Pedro Augusto Pinheiro Brito, Yuri Gonçalves Matos, Romário Parente Santos, Kátia Peres Gramacho, Alexandre Rodrigues Silva","doi":"10.1590/1984-3143-AR2025-0113","DOIUrl":"10.1590/1984-3143-AR2025-0113","url":null,"abstract":"<p><p>Bees are essential pollinators with species differing morphologically and physiologically. Understanding the variations in reproductive parameters between phenotypes is crucial. This study compares the sperm characteristics of Italian (<i>Apis mellifera ligustica</i>) and Africanized drones (<i>Apis mellifera L.</i>) raised in the Caatinga biome. Nine sexually mature Italian drones and sixteen Africanized drones from different colonies were used. Semen was collected using the endophallus eversion technique and diluted in saline solution (1:20). The parameters analyzed included: motility (optical microscopy), sperm viability (Hoechst 33342; propidium iodide), functional integrity of the plasma membrane (hypo-osmotic test), morphology and morphometry (Rose Bengal), and scanning electron microscopy. The results were expressed as mean ± standard error. Statistical analyses included the Shapiro-Wilk test to the normality of residuals and the Bartlett test to verify homoscedasticity. Comparisons between groups were performed using the Mann-Whitney and Student's t-tests (P < 0.05). Both phenotypes presented 90% sperm motility with viability of 82.4 ± 2.5% for Italians and 81.1 ± 2.4% for Africanized ones; the functional integrity of the plasma membrane was 93.4 ± 1.8% and 91.6 ± 1.5%, respectively. Regarding morphology, the percentage of normal sperm was 10.89 ± 1.66% for Italian and 12.06 ± 1.01% for Africanized, with the curled tail being the most predominant feature of sperm morphology. No statistically significant differences (P > 0.05) were observed for the above-mentioned parameters. Sperm head morphometry was significantly larger (P < 0.05) in Italian (10.04 ± 0.03 µm) compared to Africanized (9.33 ± 0.04 µm). Scanning electron microscopy analysis revealed no ultrastructural differences between phenotypes. In conclusion, there is a high degree of similarity in sperm parameters of both phenotypes under the same environmental conditions, indicating the feasibility of applying similar reproductive strategies.</p>","PeriodicalId":7889,"journal":{"name":"Animal Reproduction","volume":"23 2","pages":"e20250113"},"PeriodicalIF":2.3,"publicationDate":"2026-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13075775/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147687811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tricaine methanesulfonate and eugenol during semen collection do not affect fertilization and hatching rates on <i>Rhamdia quelen</i>.","authors":"Nathalia Dos Santos Teixeira, Lis Santos Marques, Rômulo Batista Rodrigues, Thales de Souza França, Jhony Lisbôa Benato, Maritza Pérez Atehortúa, Darlan Gusso, Itamar Cossina Gomes, Thaiza Rodrigues de Freitas, Henrique Mautone Gomes, Helen Tais Rosa-Silva, Alexandre Kleber Silveira, José Claudio Fonseca Moreira, Danilo Pedro Streit","doi":"10.1590/1984-3143-AR2024-0107","DOIUrl":"10.1590/1984-3143-AR2024-0107","url":null,"abstract":"<p><p>The reproduction of some fish species in captivity is only possible by imposing artificial reproductive procedures, and the manipulation of fish for these purposes is a stressor. Thus, anesthesia can reduce stress during handling. However, it is necessary to investigate the possible side effects on breeding and the general health of the animal. Therefore, we aimed to investigate the impact of tricaine methanesulfonate (MS-222) and eugenol (EUG) at concentrations of 300 mg L^-1 and 40 mg L^-1, respectively, on several stress- and reproductive-related parameters in <i>Rhamdia quelen</i> anesthetized before semen collection. After hormonal induction, 24 sexually mature males (534.4 ± 259 g) were randomly assigned to treatment groups and semen and blood samples were collected. Anesthesia recovery and induction time were extended in fish anesthetized with EUG; however, plasma cortisol concentrations did not differ among the treatment groups. EUG caused higher DNA fragmentation in blood cells than in the control group (without anesthesia). EUG increased the monocyte count compared to the other experimental groups. MS-222 showed a lower sulfhydryl group (SH) quantitation than the other experimental groups. The anesthetics used before semen collection in this study had no adverse effects on the fertilization or hatching capacity of anesthetized <i>R. quelen</i>. MS-222 (300 mg L^-1) and EUG (40 mg L^-1), despite being related to hematological and semen changes, did not negatively affect the reproductive capacity of <i>R. quelen</i> males. Thus, anesthesia is recommended for <i>R. quelen</i> during semen collection, considering reproductive parameters and animal welfare.</p>","PeriodicalId":7889,"journal":{"name":"Animal Reproduction","volume":"23 2","pages":"e20240107"},"PeriodicalIF":2.3,"publicationDate":"2026-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13075778/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147687865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gilts not detected in estrus in a batch farrowing breeding herd: a hormonal strategy to improve gilt utilization.","authors":"Monike Willemin Quirino, Michele Dezordi Franz, Arthur Martelli, Thomaz Lucia, Fabiana Moreira, Vanessa Peripolli, Bernardo Garziera Gasperin, Rafael da Rosa Ulguim, Ivan Bianchi","doi":"10.1590/1984-3143-AR2025-0131","DOIUrl":"10.1590/1984-3143-AR2025-0131","url":null,"abstract":"<p><p>This study evaluated reproductive performance of gilts classified as in anestrus in a batch farrowing system. Thirty-three gilts not expressing estrus within 40 days post-arrival were treated with chorionic gonadotropins, with blood collected for progesterone (P4) analysis on the same day. Thirteen gilts expressed estrus within 7 days, and 12 were inseminated (232.8 ± 2.1 days old), with 11 farrowing (91.7%; 14.2 ± 0.83 total piglets). Nineteen gilts had P4 ≤ 2.6 ng/mL at treatment; among the 20 non-responders, 10 had P4 > 2.6 ng/mL. A strong association was observed between P4 levels (≤ 2.6; > 2.6 and < 19; ≥ 19 ng/mL) and the responsiveness of gilts to gonadotropin treatment (<i>P</i> < 0.01; Cramér's V = 0.63), with greater responsiveness in gilts with P4 levels ≤ 2.6 ng/mL. Non-responsive gilts (<i>n</i> = 20) received Altrenogest for 10 - 11 days, with 17 showing estrus within 10 days and 15 farrowing (88.2%; 14.3 ± 0.84 total piglets). Estrus detection failures and silent heat likely caused misdiagnosis. Gonadotropin, with or without Altrenogest, reduced culling ~8-fold, allowing 41-58% of gilts to reach at least the 3^rd farrowing.</p>","PeriodicalId":7889,"journal":{"name":"Animal Reproduction","volume":"23 2","pages":"e20250131"},"PeriodicalIF":2.3,"publicationDate":"2026-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13004552/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147497387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preliminary insights into intratesticular and intraepididymal administration of eugenol: histological alterations and impact on sperm motility in Wistar rats.","authors":"Renner Philipe Rodrigues Carvalho, Iara Magalhaes Ribeiro, Camilo Ramirez-Lopez, Tayná Bolsam da Silva, Alex Filipe Ramos de Sousa, Arabela Guedes de Azevedo Viana, Victor de Medeiros, Ana Carolina Marta Trindade, Thanyanne Rafaela de Morais Ferreira, Luiz Otávio Guimaraes Ervilha, Mariana Machado-Neves","doi":"10.1590/1984-3143-AR2025-0026","DOIUrl":"10.1590/1984-3143-AR2025-0026","url":null,"abstract":"<p><p>This study assessed the histopathological and functional consequences of single bilateral intratesticular (InT; 200, 20, and 10 mg) and intraepididymal (InE; 50, 5, and 2.5 mg) eugenol administration in <i>Wistar</i> rats. Animals were monitored for up to 60 days, and testicular and epididymal tissues were examined for morphological alterations and sperm motility impairment. Both administration routes induced marked structural damage to the male reproductive tract. InT application led to progressive degeneration of the seminiferous epithelium, tubular atrophy, interstitial fibrosis, and focal mineralization, accompanied by reductions in both Leydig cell volumetric proportion and nuclear volume, hallmarks of impaired spermatogenesis and disrupted lumicrine signaling. In contrast, InE administration caused epithelial necrosis, intraluminal cellular debris accumulation, fibrotic remodeling, and ductal occlusion, ultimately leading to complete loss of sperm motility due to impaired maturation and obstructed transport. Although no overt systemic toxicity was observed, the findings indicate that local eugenol delivery exerts direct cytotoxic effects and promotes irreversible tissue remodeling. These results highlight eugenol's potential as a chemical sterilant and reinforce the need for further studies to evaluate the reversibility of reproductive damage, inflammatory sequelae, and interspecies variability in toxicological responses.</p>","PeriodicalId":7889,"journal":{"name":"Animal Reproduction","volume":"23 2","pages":"e20250026"},"PeriodicalIF":2.3,"publicationDate":"2026-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13004554/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147497446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prevalence of testicular disorders in dogs and cats in Fortaleza from 2020 to 2023.","authors":"Amanda Bricio Pereira de Andrade, Raul Kelvin Silveira Maia, Maria Eduarda do Carmo Moura, Herlon Victor Rodrigues Silva, Lúcia Daniel Machado da Silva","doi":"10.1590/1984-3143-AR2024-0103","DOIUrl":"10.1590/1984-3143-AR2024-0103","url":null,"abstract":"<p><p>Considering the clinical importance and the frequent occurrence of several testicular pathologies, this study aimed to assess the prevalence of testicular disorders in dogs and cats and examine their association with species, breed, and age. In order to achieve this, ultrasound reports from the hospital's system were utilized. The odds ratio was calculated for species and breed, while Pearson's correlation test was used for age. A total of 1,282 dogs and 728 cats were examined. Of these, only the intact animals were considered susceptible to testicular conditions - 1,047 dogs (81.6%) and 218 cats (29.9%). Among dogs, 33.05% presented at least one testicular disorder, compared to 10.55% of cats. The most prevalent conditions were ectopia and degeneration, with neoplasia being frequently observed in canines. Other conditions identified included orchitis, fibrosis/microcalcification, cysts, hydrocele, monorchidism, torsion, and traumatic rupture. Canine species had a higher risk of testicular disorder and cryptorchidism. In dogs, age was strongly and positively related (p<0.001) to a higher prevalence of disorders. For general testicular disorders, poodle and pinscher breeds showed higher risks, while rottweilers had a lower risk compared to mixed-breed dogs. For ectopia, pinscher, shih-tzu, and poodle breeds had higher risks. Thus, it is evident that testicular , while less prevalent conditions deserve greater attention . In felines, the occurrence is less frequent and congenital conditions like ectopia and monorchidism are more common.</p>","PeriodicalId":7889,"journal":{"name":"Animal Reproduction","volume":"23 2","pages":"e20240103"},"PeriodicalIF":2.3,"publicationDate":"2026-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13004553/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147497419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Celiotomy to collect spermatogonial stem cells in <i>Brycon orbignyanus</i> for species preservation.","authors":"Laís Gonçalves da Silva, Karel Gelina Torres-Lozano, Rômulo Batista Rodrígues, Thaiza Rodrigues de Freitas, Jayme Aparecido Povh, Louise Nex Spica, Nathalia Dos Santos Teixeira, Douglas Cosme Selle, Jhony Lisbôa Benato, Raquel Santos Dos Santos, Eduardo Thomé Nicoleti, Renata Villar Dantas, Danilo Pedro Streit","doi":"10.1590/1984-3143-AR2025-0085","DOIUrl":"10.1590/1984-3143-AR2025-0085","url":null,"abstract":"<p><p>Surgical techniques in aquatic species are underdeveloped, despite these species comprising a significant superclass among vertebrates. In the context of species preservation, studies involving the use of reproductive tissues typically involve the euthanasia of donors. Thus, in animals at high risk of extinction, the practice of sacrificing them presents a point of contradiction between ex situ conservation efforts. The objective of this study was to compare the viability of spermatogonia stem cells (SSCs) collected from <i>Brycon orbignyanus</i> using conventional methods (euthanasia) versus a surgical procedure. Lateral celiotomy was performed on 27 immatures males to obtain a portion of gonadal tissue. The fish were divided into three groups (n=9), with each group receiving polyglactin 910, polyester, or catgut sutures, respectively, for celiorrhaphy. Dermorraphy was performed using nylon sutures in all groups. A. An additional euthanasia group consisted of nine animals exposed to 20 mg/L of propofol. The survival rate over a 48-hour period was 100% for the polyglactin 910 group and 77.7% for the polyester and catgut groups. Additionally, the viability of SSCs was similar between the euthanasia and surgical procedures. The lateral celiotomy technique is feasible for obtaining SSCs in fish with laterally compressed anatomy, such as <i>B. orbignyanus</i>. Additionally, the technique allows the preservation of SSCs as a model for endangered fish species.</p>","PeriodicalId":7889,"journal":{"name":"Animal Reproduction","volume":"23 1","pages":"e20250085"},"PeriodicalIF":2.3,"publicationDate":"2026-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12970993/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147430407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Yolk sac development in dogs: from morphology to functional aspects.","authors":"Caio Garcia Barbosa da Silva, Julia Rodrigues Greghi, Maria Fernanda Frasson Pontes, Guilherme Schiess Cardoso, Maria Isabel Mello Martins, Carlos Eduardo Ambrósio, Phelipe Oliveira Favaron","doi":"10.1590/1984-3143-AR2025-0104","DOIUrl":"10.1590/1984-3143-AR2025-0104","url":null,"abstract":"<p><p>The yolk sac (YS) is a multifunctional and essential structure for early maternal-fetal interactions, playing roles in nutrient supply, organogenesis, immune modulation, and hematopoiesis. Unlike most species, dogs maintain the YS until the end of pregnancy, yet little is known about its functional activity, particularly in later stages. Animal models are crucial for exploring maternal-fetal processes and offering insights into comparative development, including in humans. This study aimed to analyze the YS structure in canine embryos and fetuses at early (up to 20 days, n = 6), middle (21-40 days, n = 6), and late (41-60 days, n = 6) stages. Gestational age was estimated using crown-rump length (CRL) and external anatomy. Samples from the university's Veterinary Hospital and neutering campaigns in Londrina (Paraná, Brazil) were fixed in 10% formaldehyde for morphological analysis (H&E, PAS, and Picrosirius red) or 4% paraformaldehyde for OCT4 immunostaining (CEUA/UEL protocol number 029.2022). Histologically, the YS showed a trilaminar structure with blood islands in the intermediate layer surrounded by mesenchyme. Within these islands, undifferentiated cellular niches (OCT4+) were identified. During gestation, the YS changed from a thin, smooth, pale-red membrane to a wrinkled structure with narrowed ends and a thickened central region, resembling a \"whale tail.\" The red color, indicative of vascularization, intensified with blood island enlargement. Collagen secretion, particularly type I, progressively increased around the blood islands. Glycoprotein deposits persisted until late gestation, as shown by PAS staining. These findings highlight the structural, secretory, and reserve roles of the canine YS throughout pregnancy.</p>","PeriodicalId":7889,"journal":{"name":"Animal Reproduction","volume":"23 1","pages":"e20250104"},"PeriodicalIF":2.3,"publicationDate":"2026-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12970995/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147430344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hormone residues are not detected in zero water exchange biofloc system during tilapia masculinization even in higher feed input.","authors":"Dara Cristina Pires, Érika Ramos de Alvarenga, Franklin Fernando Batista da Costa, Kelly Moura Keller, José Fernandes Bezerra, Mariana Parrini Ferreira, Gabriela Lago Biscoto, Isabela Lopes Samary, Karen Beatriz Guerra Lima, Vinícius Monteiro Bezerra, Caroline Lopes de Melo, Lee Deyver Carvalho Pena Mansur, Williane Ferreira Menezes, José Fernando Paz Ramírez, Luiza Fujii Almeida, Daiana Dos Reis Pelegrine, Marcelo Rezende Luz, Eduardo Maldonado Turra","doi":"10.1590/1984-3143-AR2025-0106","DOIUrl":"10.1590/1984-3143-AR2025-0106","url":null,"abstract":"<p><p>How intensive the masculinization period of Nile tilapia can be in biofloc technology (BFT) based on higher stocking densities and a zero-water exchange protocol to mitigate the environmental impact has not been studied yet and needs investigation. Thus, our objective was to determine the optimal stocking density for reduction of hormonal effluent in BFT, better growth and masculinization rate of Nile tilapia larvae, and lower total variable cost. Five stocking densities (1.5, 3, 4.5, 6, and 7.5 larvae ∙ L^-1) with four replicates were tested. Tilapias were fed with 60 mg of 17α-methyltestosterone (MT) ∙ Kg^-1 of feed for 28 days, and with hormone-free feed until the common selling body weight of 1g. Water quality variables showed no significant differences between treatments, except for total settleable solids, pH, and final total organic carbon, that had a negative, positive and quadratic linear pattern with the increasing of stocking density, respectively. Growth performance variables such as final body weight, specific growth rate, survival and individual feed intake (and consequently hormone input) were superior at the lower stocking density. Masculinization rate (98.87%) did not differ among treatments, but total variable cost increased to produce 1g fingerlings in higher stocking densities. Hormone residue was not detected in BFT water of any treatment 12 hours after the last feeding so, in conclusion, even being the highest hormone input in the system, 1.5 larvae ∙ L^-1 is the best level of stocking density studied for tilapia masculinization in a zero-water exchange BFT.</p>","PeriodicalId":7889,"journal":{"name":"Animal Reproduction","volume":"23 1","pages":"e20250106"},"PeriodicalIF":2.3,"publicationDate":"2026-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12970992/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147430359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}