牛体外授精技术的研究与展望

本文阐述了体外受精技术在牛胚胎工程和育种研究中的意义，介绍了牛体外受精技术的研究历史和目前的研究进展，并就牛的体外受精技术当前研究存在的问题作了评述，对其前景做了展望。     

中华鳖胚胎细胞体外培养的研究

研究中华鳖胚胎细胞体外培养适宜培养渗透压、培养基和培养温度等条件,并进行传代试验,结果表明,胚胎原代细胞在２５－２８℃,渗透压２５０ｍｍｏｌ／ｋｇ,ＲＰＭＩ－１６４０＋１０％小牛血清培养液及无ＣＯ２的条件下,生长良好,７２ｈ长满足 单层,并能顺利传代。细胞动力学试验表明,传代细胞１－３代为适应期、４－６代为旺盛期、７－９代为衰退期。第６代细胞以体组型分析,其染色体为整二倍体,并未发生转化。     

牛胚胎分割技术研究进展

牛胚胎冷冻的成功,使胚胎移植技术不受时间、地域的限制,并且可以做到对受体进行选择,从而可提高移植妊娠率;牛胚胎分割的成功,是增加胚胎数目和生产同卵双胎或多胎,获得更多牛犊的一个有效方法。如果将胚胎冷冻和胚胎分割技术结合起来,那末就可以达到既增加胚胎数目,降低胚胎移植成本,又利于胚胎移植技术在生产中推广应用的双重目的。     

牛胚胎生产和移植实验方案

该方案通过超排和体外受精两种方式来生产牛胚胎,并采用非手术方法将胚胎植入本地黄牛、西杂牛子宫内,完成妊娠过程.同时结合胚胎保存、胚胎分割等技术手段,扩大资源和胚胎利用的时空局限.所有这些实施程序同样可以用于其他品种牛的胚胎生产和移植.其实施步骤包括以下内容. 1.超数排卵生产胚胎 1.1.供体、受体的选择 选择身体健康,无生殖道疾患,发情正常的纯血优良母牛作为供体.所选母牛最好为4-6岁的经产母牛,有三代系谱记录.体重在500kg以上.选择后的供体母牛最好转群饲养. 选择经产的、无生殖道疾患和无习惯性难产的本地黄牛和西杂母牛作为受体牛,选择的体型应适度.受体牛群同样要进行检疫,防疫和驱除体内外寄生虫,并进行生殖器官检查. 供体、受体牛均应有一个情期的发情记录,如果尚无,最好将供、受体母牛转群、作一个自然情期观察和记录.     

波尔山羊卵巢卵母细胞的体外培养与体外受精

以10只不孕不育波尔母山羊群为试验动物穴供体雪,采用超数排卵、活体采卵、卵母细胞体外成熟培养以及体外受精等技术方法,探讨有繁殖障碍波尔山羊群体繁育正常后代的有效技术途径。在该实验中试验动物中7只经超数排卵处理后诱导发情,利用特制的采卵装置成功地进行了6只供体的活体采卵熏从10个卵巢上成功地采集到30枚形态学正常的卵母细胞。经体外成熟培养后24枚成熟卵母细胞进行了体外受精处理,获得16枚正常受精卵,移植到4只同期发情的当地山羊受体输卵管内,经3个月妊娠检验判定,其中两只受体受孕。该研究为解决不孕不育波尔山羊群繁殖后代的难题探索出一条新途径。     

浅谈牛品种改良与人工授精技术研究

当前,随着我国全民经济的发展,人们物质生活水平逐步提升,市场对于牛肉的需求也不断提高。对牛品种进行改良,可以提高肉牛的质量、加快养牛行业的发展。分析牛品种的改良,包括种公牛的选择、种母牛的选择等;并分析人工授精技术的重点,如做好准备的工作、保护冷冻精液等,以此促进养牛业的发展。     

牛病特点及常见牛病的防治技术

随着养牛业的大力发展,牛病随着扩大的养牛规模日益增多,困扰着每一个养殖户,给养殖户的经济效益带来了严重的威胁。其次,人的健康还会因为一些牛病受到威胁,如人和牛都会患上的传染性结核病,这种传染病的死亡率较高,是我国的五大传染病之一。因此,对牛病的特点以及常见牛病的防治技术进行探究,是非常迫切且有必要的。     

牛的人工授精技术

牛人工授精技术是采用假阴道人工采集公牛的精液。经检查并稀释处理和冷冻后,再用输精器将精液输入母牛的生殖道内,使母牛排出的卵子受精后妊娠的技术。牛人工授精技术是一种有价值的牛育种技术,通过牛人工授精技术进行品种改良,提高了牛的繁殖率,加快养牛业发展。     

影响猪卵巢卵母细胞体外成熟的若干因素

介绍了以屠宰场废弃的猪卵巢为材料,通过系统技术途径得到猪早期胚胎的基本方法。新鲜的猪卵巢采集后,25～35℃条件下保存,在3h内进行卵泡卵母细胞与卵丘细胞复合体(COCs)采集与分级,对COCs中卵母细胞体外成熟(IVM)、体外受精(IVF)及其受精卵体外发育(IVD)等关键技术环节进行了系统地探索,重点探讨了不同发育阶段(直径大小)卵泡卵母细胞、不同培养系统与添加成分以及不同培养时间等关键因素对猪卵母细胞IVM的影响,并对其IVF卵裂能力进行了比较与评价。实验结果表明,采用mTCM199作为基础成熟培养系统液,并添加ф5～8mm卵泡液(pFF)和雌二醇(E2),ф2～8mm卵巢卵泡COCs经IVM40h可得到较高的成熟率(66.7%)和IVF卵裂率(29.2%)。本研究初步建立了猪2-4-细胞早期胚胎的体外批量生产技术,可望进一步改进和完善,应用于养猪业科研与生产实践。     

牛品种改良重点技术

随着我国对畜牧良种补贴力度的加大,奶肉牛品种改良规模、改良水平以及改良效果均在显著提高。从目前牛品种改良的发展趋势入手,分别对牛品种改良的基本情况、牛品种改良的现状进行分析,指出目前牛品种改良主要存在的问题是良种繁育体系不完善、养殖规模小且缺乏科学技术、杂交母牛利用低等,并提出了相应改进措施。牛品种改良技术的关键在于掌握好母牛发情特点,做好母牛发情鉴定,做好输精前准备,合理选择配种时间和方式,适时输精,通过牛品种改良技术的提升促进我国畜牧牛业更好的发展。     

实验室中海胆的人工授精及幼体培育

海胆作为实验材料需在实验室条件下进行人工授精和培育。本文介绍了实验室中海胆人工授精的方法,从受精卵到稚海胆各发育阶段的培育条件的培育方法。     

胰蛋白酶改性的研究现状和展望

近年来,随着蛋白酶改性研究的不断进步,试图提高胰蛋白酶稳定性的有关研究也取得了长足的发展。本文综述了目前国内外关于胰蛋白酶的固定技术和大分子修饰技术的研究现状,并提出了通过定点改造和体外定向进化技术提高胰蛋白酶稳定性的可能。     

牙鲆鳃细胞与中国对虾淋巴细胞杂交细胞的体外培养

利用ＰＣＧ介导的细胞融合方法，将已成系的牙鲆鳃细胞与中国对虾淋马细胞进行细胞杂交，对所获得的杂交细胞用ＭＥＭ：ＭＰＳ（１：１）混合培养液进行体外培养，培养５天后发现，杂交细胞长成了单层，传代培养后仍可继续生长和分裂，通过逐渐提高混合培养液中ＭＰＳ的所占比例所筛选出的杂交细胞，目前已传１２代，生长和分裂势头仍然十分旺盛，通过接种对虾杆现毒发现，１０天后杂交细胞出现了明显的病变特征（细胞收缩变团圆，脱落，死亡），至１４天细胞使几乎完全脱臂死亡，取病变细胞的培养上清０.3mL再加入到一瓶已长成单层的杂交细胞中，结果５天后杂交细胞也出出了明显的病变特和下，而未接种病毒的对照组杂交细胞生长正常，可禄步认为我们所得到的杂交细胞确为对虾（杆状）病毒的靶细胞。     

虎纹蛙病毒体外培养及其理化特性

从发病濒死的虎纹蛙（Rana tigrina rugulosa)蝌蚪中分离到一种病毒，在25℃条件下，该病毒能在鲤鱼表皮瘤细胞系（EPC），胖头Shiu肌肉细胞系（FHM）和草鱼性腺细胞系（CO）三种鱼类细胞上产生空斑状的细胞病理变化（CPE）。该病毒对氯仿，热（56℃，20min)和酸（pH3)敏感，其体外培养的适合增殖温度范围为20-30℃，电镜下观察，病毒为对称的二十面体，切面正六边形，对角直径125nm左右。     

Fertilization success and blastomere morphology as predictors of egg and juvenile quality for domesticated Atlantic cod,Gadus morhua,broodstock

We investigated if simplified routines based on blastomere morphology and fertilization success can be used as predictors of egg and embryo viability in Atlantic cod, and abnormal blastomere morphology is related to juvenile deformities. Egg morphology data from 312 families that were produced by hand stripping of gametes were used. Fertilized eggs from all families were separately incubated in 25 L incubators. Blastomere morphology and fertilization success were assessed at 16–32 cell stage. Embryo mortality was measured until hatch. Fertilization success showed a significant positive correlation with the proportion of normal blastomere and 74% of the variation in the incidence of blastomere abnormality was explained by fertilization success. Juvenile deformities were positively correlated with blastomere abnormality and 8% of the variation in juvenile deformities was explained by incidences of blastomere abnormality. To our knowledge, this is the first direct evidence showing that incidences of blastomere abnormalities may be related to cod juvenile deformities. Our results suggest that fertilization success and the occurrence of blastomere abnormalities could be easily adopted by commercial cod hatcheries for the early determination of egg quality.     

Gill amoebae from freshwater rainbow trout (Oncorhynchus mykiss): In vitro evaluation of antiparasitic compounds against Vannella sp.

Gill parasitic infections challenge farming of rainbow trout (Oncorhynchus mykiss, Walbaum) in freshwater facilities. Apart from flagellates (Ichthyobodo, (Pinto) and ciliates (Ichthyophthirius (Fouquet), Ambiphrya (Raabe), Apiosoma (Blanchard), Trichodinella (Sramek-Husek) and Trichodina (Ehrenberg)), we have shown that amoebae are prevalent in Danish trout farms. Gills were isolated from farmed rainbow trout in six fish farms (conventional and organic earth pond and recirculated systems) and placed on non-nutrient agar (NNA) moistened with modified Neff's amoeba saline (AS) (15°C). Gill amoebae from all examined fish colonized the agar and were identified based on morphological criteria showing species within the genera Trinema (Dujardin) (family Trinematidae), Vannella (Bovee) (family Vannellidae). In addition, hartmannellid amoebae were recorded. We established a monoculture of Vannella sp., confirmed the genus identity by PCR and sequencing and performed an in vitro determination of antiparasitic effects (dose–response studies) of various compounds including sodium chloride (NaCl), hydrogen peroxide, peracetic acid, formalin, aqueous garlic and oregano extracts and a Pseudomonas H6 surfactant. All amoebae were killed in concentrations of 16.90 mg/ml (garlic), 17.90 mg/ml (oregano), NaCl (7.5 mg/ml), hydrogen peroxide (100 µg/ml), peracetic acid (0.03 µg/ml), formaldehyde (25 µg/ml) and the Pseudomonas H6 surfactant (250 µg/ml).     

对渔业企业在长短期中盈亏状况和生产规模的分析

利润最大化是市场经济条件下,渔业企业追求的目标,那么,渔业企业在什么条件下才能获得最大利润以及在长短期中,随着市场价格的变化,渔业企业的盈亏状况怎样和如何调整生产规模,才能获得最大利润。本文就这些问题进行了分析。     

Effects of different fertilization and feeding regimes on the production of integrated farming of rice and prawn Macrobrachium rosenbergii (De Man)

An experiment was conducted in rice field plots each of 30 m² to determine the appropriate combination of feeding and fertilization regimes for the giant freshwater prawn Macrobrachium rosenbergii (De Man, 1879) cultured along with rice in rice fields. There were four treatments: rice culture only with regular fertilization (A, control); rice–prawn integrated culture with regular fertilization (B); rice–prawn integrated culture with basal fertilization and commercial feed (C) and rice–prawn integrated culture with regular fertilization and commercial feed (D). Juvenile prawns of 1.5‐g size were stocked on the third day after rice transplantation at a density of 2 prawns m^?2 and fed twice daily at 5% reducing to 2% of body weight during the experiment. The rice yield in treatment D (0.42 kg m^?2) was significantly higher than that in other treatments (0.34, 0.36, 0.34 kg m^?2 in treatments A, B, C respectively). Prawns grew significantly faster (P<0.05) in treatments C and D (23.8±0.9 and 22.0±1.7 g prawn^?1 respectively) than in treatment B (14.7±1.6 g prawn^?1). Prawn production in treatment C (347±13 kg ha^?1 crop^?1) was significantly (P<0.05) higher than that (234±30 kg ha^?1 crop^?1) in treatment B, while in treatment D (296±53 kg ha^?1 crop^?1) it was not significantly different from that in treatments B and C (P>0.05). Treatment C gave the highest economic returns among all treatments, followed by treatments D and B, indicating that the combination of basal fertilization and commercial feed is the most appropriate nutrient input regime for the rice–prawn integrated culture system.