检索结果-南通市图书馆

Subzonal insemination with primary spermatocytes in mouse

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1997年第15期42卷 1304-1308页

作者： Liu, L Sun, QY Duan, CW Liu, H Song, XF Qian, JF Chen, DY CHINESE ACAD SCI INST ZOOLSTATE KEY LAB REPROD BIOLBEIJING 100080PEOPLES R CHINA

IT is well known that oocytes, in general condition, can be penetrated by sperm rather thanround spermatids. In 1993, Ogura injected round spermatid nuclei into hamster oocytes anddemonstrated that the spermatid nuclei could transform into pronuclei with DNA synthesis andthat their chromosomes mingled with oocyte chromosomes immediately. In order to avoid themechanical damage to the oocytes, an alternative method, cell-to-cell fusion, was used. Ap-proximately 20%—40% and 30% of round spermatids could be fused with oocytes by

关键词： primary spermatocyte subzonal insemination electrofusion mouse.

THE insemination OF GOLDFISH(CARASSIUM AURATUS) OOCYTE MATURED IN VITRO

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Oceanology and Limnology 1991年第1期9卷 88-93页

作者：王壬学吴贤汉周晶张士璀马英杰吴尚懃史瀛仙 Institute of Oceanology Academia Sinica Qingdao 266071 Institute of Developmental Biology Academia Sinica Beijing 100080

Full maturation of goldfish oocyte was induced in vitro by 17 a-hydroxy-20B-dihydroprogesterone. The oocyte maturation involves GV migration to the periphery of the oocyte and germinal vesicle breakdown (GVBD). In the experiment, incubation duration for GVBD varied in different broods of oocytes. Generally, if the duration for GVBD was shorter than 6 h, oocytes would have a better chance to survive after maturation and insemination. The maturation of nucleus (GV) and cytoplasm are not synchronous. Cytoplasm maturation occurs several hs after GVBD. Oocytes inseminated 8-9 h after GVBD have the highest fertilizing and hatching rate. Fertilized ova matured in vitro can develop to sexually mature adults capable of reproduction.

关键词： maturation migration mature oocyte insemination periphery chance Cytoplasm incubation varied

Artificial insemination Service Efficiency and Constraints of Artificial insemination Service in Selected Districts of Harari National Regional State, Ethiopia

在线全文

学校读者我要写书评

暂无评论

Open Journal of Animal Sciences 2018年第3期8卷 239-251页

作者： Belayneh Engidawork Haramaya University Dire Dawa Ethiopia

The study was conducted to evaluate efficiency of artificial insemination (AI) service and constraints of AI service selected Districts of Harar National Region State, Ethiopia. A total of 320 dairy cows were randomly selected from six districts of Harari region;Jin’Eala, Shenkor, Hakim, Dire-Teyara, Aboker, Sofi. Data on dairy cattle management, artificial insemination (AI) service efficiency and constraints of AI service were generated using structured and semi-structured questionnaire. Forty three straws of frozen semen was sampled from the regional AI service centre, thawed and evaluated at the region level for its quality (motility, viability and morphology) following standard procedures. The overall mean percentage of frozen semen motility at regional level was 49.6. Semen production period (batch) and Breed (exotic blood level) had no effect on frozen semen motility. The mean percentage of viable (live) spermatozoa was 58.3. Sperm viability was not significantly influenced by Semen production period (batch) and, breed (exotic blood level). The overall mean percentages of major and minor sperm morphological defects were 5.6 and 21.8, respectively. Frozen sperm major morphological defects were significantly affected (p 0.05) on frozen sperm major morphological defects. Frozen sperm minor morphological defects were not significantly affected (P > 0.05) by both semen production period (batch) and sire breed (exotic blood level). The mean number of service per conception (NSC) in the current study was found to be 1.6. It was not significantly affected by previous season of calving, previous year of calving and parity. Non-return rate value of Harari region AI service center was 48.1%. Major constraints of AI service delivery system in the study area were feed shortage, problem in heat detection, service charge for AI, distance from AI service centre and husbandry problem. Additional

关键词： Dairy Smallholder Semen Estrus insemination

A new device for deep cervical artificial insemination in gilts reduces the number of sperm per dose without impairing final reproductive performance

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Animal Science and Biotechnology 2019年第2期10卷 402-409页

作者： Pedro J.Llamas-López Rebeca López-úbeda Gustavo López Emily Antinoja Francisco A.García-Vázquez Department of Physiology Faculty of VeterinaryCampus Mare NostrumUniversity of Murcia30100 MurciaSpain Department of Cell Biology and Histology Faculty of MedicineCampus Mare NostrumUniversity of Murcia30100 MurciaSpain Institute for Biomedical Research of Murcia(IMIB-Arrixaca) MurciaSpain Cherkizovo Group LipetskRussia.

Background: The aim of this study was to evaluate the reproductive performance of a new artificial insemination(AI) device specifically designed for gilts(Deep cervical AI, Dp-CAI) by means of which the sperm is deposited deeply in the cervix(8 cm more cranial than in traditional cervical insemination-CAI). New AI techniques have arisen in recent decades in the porcine industry, such as post-cervical artificial insemination(PCAI), which involves depositing the sperm in the body of the uterus [through a catheter(outer tube)-cannula(inner tube)] rather than by CAI. Although the PCAI method has been successfully applied in farm conditions to reduce sperm doses without impairing the reproductive performance, this technique has limitations in gilts mainly because of the difficulty involved in introducing the inner cannula through the cranial part of the cervix. For this reason, the Dp-CAI method described herein may be considered as an alternative to CAI and PCAI methods in ***: Gilts were divided in two experimental groups: 1) Dp-CAI: gilts(n = 1166) inseminated using 1.5 × 109 sperm/45 m L;2) CAI(as a control group): gilts(n = 130) inseminated using 2.5 × 10~9 sperm/85 mL. The Dp-CAI method was successfully applied in 88.90% of the gilts, with no differences detected between gilts with 1 or 2 previous oestrus cycles, although the catheter could be introduced more deeply in 2 oestrus gilts(P insemination device that could not be introduced increased(at the moment of insemination), so the success rate of the Dp-CAI device fell, as did the total number of piglets born. When the reproductive output in CAI and Dp-CAI was compared, none of the parameters analysed [pregnancy and farrowing rates(%), and number of piglets born(total and live)] showed significant ***: The use of the Dp-CAI technique provides a new AI method as an alternative to CAI and PCAI for pigs. The device, especially designed for gilts, was used w

关键词： Cervix Intrauterine Nulliparous Porcine Post-cervical insemination

Assessment of Artificial insemination in Camel

在线全文

学校读者我要写书评

暂无评论

Open Journal of Animal Sciences 2019年第2期9卷 207-216页

作者： Belayneh Engidawork Demissie Haramaya University Haramaya Ethiopia

The objective of this review is to confer semen collection and processing, and semen deposition technique in camel. Artificial insemination is an important technique to ensure rapid genetic improvement in camels. The use of AI has been reported in camel, although insemination trials are rare. The widely accepted methods of semen collection include electro ejaculation and artificial vagina (AV), but flushing of the epididymis with saline solution can also be used as an alternative. Depending on the method of semen processing, semen is usually used in raw condition or after extension. Whole semen is used within minutes or after few hours in the fresh raw method. In short-term preservation or liquid semen (within a few hours or days) and long-term preservation or frozen semen (months or years), extension of the semen ejaculate is carried out by adding extenders which is required in more efficient use of AI. Semen is extended under different temperatures (30°C, 25°C or 4°C), in short-term preservation. Cryopreservation is used to carry out long-term preservation. Different freezing procedures are represented by packaging methods such as ampoules or in plastic straws with different volumes (0.25, 0.5 or 4 ml) and pellets. The best time for insemination can only be determined by rectal palpation of the ovaries and/or ultrasonography. The other alternative is to inseminate at known intervals following induction of ovulation by hormonal treatment with human-chorionic gonadotropin (hCG) or gonadotropin-releasing hormone (Gn-RH). The semen should be deposited into the uterus at least 24 hours after the onset of ovulation. Pregnancy rates depend on the semen extender, site of deposition and number of sperm deposited. Blood or milk progesterone assays, rectal palpation, and ultrasonic image detection of pregnancy are commonly used approaches of pregnancy diagnosis in camel.

关键词： insemination Camel Semen Deposition Preservation

Comparison of Two insemination Programs in Synchronized Early Postpartum Zebu Cows under Tropical Conditions: An Economic Appraisal

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Veterinary Medicine 2015年第12期5卷 234-242页

作者： Adalinda Hernández Carlos Salvador Galina Ramiro Diaz Ivette Rubio Manuel Corro Juan José Romero Departamento de Reproducción Facultad de Medicina Veterinaria y Zootecnia Universidad Nacional Autónoma de México Mexico City México Centro de Ensenanza Investigación y Extensión en Ganadería Tropical Facultad de Medicina Veterinaria y Zootecnia Universidad Nacional Autónoma de México Tlapacoyan México Escuela de Medicina Veterinaria Universidad Nacional Heredia Costa Rica

To evaluate an artificial insemination program in postpartum Bos indicus cows and by using deterministic models, to estimate the possible economic advantages of insemination by appointment over detected estrus, sixty-three multiparous animals were synchronized using a progestagen device inserted at day 31 and withdrawn after 9 days (average time for withdrawal was 40.9 ± 6.8 days). Cows were observed continuously from 0700 to 1800 during 72 h. The percentage of animals detected positive to estrus by riding behavior was 43.4%, transrectal palpation, 22% and heat detector patches, 4.6%. The percentage of cows ovulating as evidenced by progesterone samples taken at 9 and 11 days after the average estrus response was 73%. The economical assessment by using the values obtained in the present study afforded that the cost of semen, ovulation rate and fertility point to a definitive advantage of using AI at fixed time over a program based on estrus detection.

关键词： insemination Estrus Detection Behavior Bos indicus

Estrus Synchronization and Artificial insemination with Fresh and Chilled Semen in Assaf Ewes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Agricultural Sciences 2018年第1期9卷 8-22页

作者： Raquel Fornazari óscar Mateus Teresa Correia Hélder Quintas Raimundo Maurício Anderclei Conradi Lucas Francisco Armindo álvaro Ramiro Valentim Federal Technology University of Paraná Campus of Dois Vizinhos Dois Vizinhos Brasil Department of Animal Science Agrarian Superior School of Braganza Braganza Portugal Mountain Investigation Center Polytechnic Institute of Braganza Braganza Portugal Polytechnic Superior Institute of Kwanza Sul Sumbe Angola

This paper aims to study the efficiency of two short-term progestagen (FGA vs. MAP) + eCG treatments in estrus synchronization and artificial insemination (AI) with fresh or chilled semen in Assaf ewes fertility rate. All ewes received a subcutaneous implant of exogenous melatonin 45 days before been treated with short-term progestagens + eCG. By June 1st, ewes were divided in two groups: half was treated with an intravaginal sponge impregnated with 20 mg of FGA and the other half with an intravaginal sponge impregnated with 60 mg of MAP. Progestagen treatments lasted for 6 days. At sponge withdraw, all ewes were injected with 750 IU of eCG. Ovarian activity was assessed by plasmatic progesterone levels before and after progestagens + eCG treatment. Semen was collected by electro ejaculation and extended with Andromed? or OviXcell?. AI was performed 55 hours after eCG administration with fresh or chilled semen. During AI several factors were assessed: vagina mucosa color and lubrication, external cervical Os type, cervical mucous viscosity, semen deposition place and seminal cervix outflow. Semen was deposited as deep as possible without distress or trauma cervix mucosa. All Assaf ewes presented cyclic activity before progestagen + eCG treatments (2nd fortnight of May). Short-term progestagen + eCG treatments were equally efficient (100.0%). About 76.5% of Assaf ewes were pregnant 41 days after AI. Fertility rate was influenced by external Os type, semen deposition place and seminal cervix outflow. However, this rate was not conditioned by vaginal color or lubrication, cervical mucus viscosity, semen preservation technic and semen extender.

关键词： Sheep Assaf Estrus Synchronization Artificial insemination

Morphology of Gametes and insemination in the Vestimentiferan <i>Riftia pachyptila</i>

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Marine Science 2012年第3期2卷 96-102页

作者： A. L. Drozdov S. V. Galkin A.V. Zhirmunsky Institute of Marine Biology FEB RAS ul. Palchevskogo Vladivostok Russia P.P. Shirshov Institute of Oceanology RAS Nakhimovsky pr. Moscow Russia

Ultrastructure of gametes (sperm and eggs) of vestimentiferan tubeworms and external-internal insemination by means of spermatozeugmata in Riftia pachyptila were described. The spermatozoa of Riftia are threadlike, about 130 μm long, and have a diameter of about 0.7 μm, narrowing to 0.2 μm in the apical portion of the macrodome, and pointed at the end of the tail. Oocytes are produced by the ovaries at the first meiotic prophase stage. The early oocytes are small, hardly exceeding 10 μm in diameter, spherical cells with a poorly differentiated cytoplasm and large nuclei with a nucleolus. Completely formed oocytes reaching up to 130 μm in diameter leave the ovary, their germinal vesicle is unresorbed and has a nucleolus. They are coated by a yolk membrane of 1.2 μm. The eggs enter the oviduct, move along, and accumulate in its expanded anterior portion, the ovisack. The sperm is released in seawater as sperm packages, each having the shape of a torch. Then sperm moves to females and sperm packages at the posterior end of the oviduct surrounding of eggs. Inside the female tube, spermatozoa and, possibly, yet unsplit sperm packages, invade the oviducts through genital openings, where the unfertilized eggs are already present in the terminal portion of the eggsack.

关键词： Riftia Sperm Eggs insemination Spermatozeugmata

Effect of administration of phenylephrine immediately after low dose insemination on pregnancy rates in mares

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Obstetrics and Gynecology 2013年第10期3卷 722-726页

作者： Theresa Beachler Renan Sper C. Scott Bailey James Shewmaker C. Nick Buchanan Anne Josson-Schramme Michael Whitacre College of Veterinary Medicine North Carolina State University Raleigh USA School of Veterinary Medicine Ross University Basseterre Saint Kitts and Nevis

There is considerable pressure on equine veterinarians to achieve good pregnancy rates with very small doses of semen. Phenylephrine administration in the rabbit increased numbers of oviductal, uterine, and cervical sperm, myometrial contractions, and fertilized ova after low dose insemination. The use of phenylephrine to enhance uterine contractility and fertility has not been investigated in the mare. Thus, the objective of this study was to determine if phenylephrine administration would result in clinically acceptable pregnancy rates in mares bred by low dose insemination. The hypothesis (Ha) was that pregnancy rates would be significantly higher in mares receiving phenylephrine compared to saline controls. Six pony mares and eight horse mares were enrolled in this study. Mares were inseminated within 24 hours of ovulation with 30 million progressively motile spermatozoa from a single fertile stallion. Immediately following insemination, mares were administered either phenylephrine (0.06 mg/kg) or 1mL of saline via IV injection. Pregnancy status was determined 14 days following ovulation via transrectal ultrasonography. Pregnancy rates in phenylephrine treated mares were 44% (4/9) while 22% (2/9) in saline-treated mares (P > 0.05).

关键词： Artificial insemination Low Dose insemination Equine Phenylephrine