黑龙江垦区肉牛杂交组合的效果观察

引进国外优秀公牛与本地黄牛进行杂交组合,在黑龙江垦区有3种较常用的模式,作者为此进行了大量的试验研究,拟在通过杂交组合模式,分析几种杂交组合的效果。     

应用腹腔内窥镜提高山羊胚胎移植受胎率的试验

在黑龙江八一农垦大学繁殖实验室和建三江营局红卫农场，对64只受体山革进行胚胎移植试验，谊试验将饲养管理蒂件和超排处理方法相同的受体羊随机分为两组，即对照组A和试验组B，每组32只羊，对照组A采用常规手术法进行胚胎移植，受胎率为50％（16／32）；试验组B采用腹腔内窥镜法进行胚胎移植，受胎年为75％（24／32）。两组试验差异显著（P〈0．05），B组方法明显好于A组。     

牛双胎生产技术与相关基因研究进展

牛是单胎物种,但牛在繁殖过程中会产双胎.在某些特定的生产条件下,双胎可能被认为是一种理想的性状,因为该性状会增加每头母牛的断奶牛重从而提高盈利能力.但目前有关对牛双胎机制的相关研究结果尚不明晰.文章综述了有关肉牛、奶牛双胎的研究意义、常用的繁殖技术、双胎相关基因的研究历史与现状及存在的问题,以期对牛的繁殖性能改良、繁殖管理效率提高以及基因功能等研究提供参考.     

猪人工授精与自然交配的受胎效果比较

对328头1～3胎的大白母猪实施了人工授精(2次、3次)和自然交配(3次),比较了两种配种方法和输精方式对母猪受胎率和产仔数的影响。结果表明:两种配种方法和输精方式对3个胎次母猪的受胎率和窝均产仔数影响均不显著(P0.05)。说明人工授精可以取代自然交配在规模化猪场推广应用,并且在规模化猪场实施2次人工授精也是可行的。     

海参疾病学研究进展

海参具有极高的营养和药用价值,历来被视为海珍奇品。近年来,海参价格不断上涨,市场需求量迅速增加,随着采捕强度的增大,导致自然资源量急剧减少。为解决市场膨胀和资源缩减问题,海     

牛胚胎日龄与移植时间对妊娠率的影响

为探讨胚胎移植过程中受体与胚胎日龄的最佳结合点,对移植受体牛的发情天数与胚龄进行了研究.选取北京奶牛中心的3种不同胚龄的A级胚胎,分成2组进行移植,A组采用随机移植方案,B组采用同步移植方案.B组妊娠率为(61.11%)高于A组的妊娠率(25.81%),两组之间存在显著性差异(P＜0.05).结果表明,在胚胎移植中同步移植好于随机移植的效果.通过本试验的研究,以期在生产实践中对胚胎移植技术的应用和推广有所借鉴.     

不同药物对荷斯坦青年母牛超排效果的研究

本研究以青年荷斯坦母牛为试验对象,在供体母牛发情周期的任意一天(发情当天除外),于供体牛阴道放置CIDR(孕酮的缓释装置).同时肌注Eb 2 mg和P4激素100 mg,在放置阴道栓的第五天开始按常规4天递减法肌肉注射FSH超数排卵.结果发现,应用进口FSH超排组,有23头发生卵巢囊肿,同时乳房有不同程度的发育,应用国产FSH超排组,只有3头牛发生卵巢囊肿,且其乳房并无发育.表明在超数排卵时,应根据所选药物及超排牛群内牛只个体的不同,选择适宜的超排剂量.     

影响牛胚胎采集效果的因素

本文在全面分析胚胎采集过程中的每个技术环节基础上,指出影响采胚效果的影响因素,并提出了相应的解决办法及应对措施.     

对虾免疫机能研究概况

Shrimp farming is an important source of revenue and employment in many developing countries.However, infectious diseases have adversely affected the profitability of shrimp industry. For this reason, disease prevention is a priority and shrimp immunology has become a crucial research area of this field. In this paper, the current importance and problems of shrimp-culture were described and the research advances in shrimp immunological defence mechanisms were summarized. The immunological tools are powerful and useful to evaluate the health state of the shrimp. The immunologies of shrimp mainly consist of cellular immunity and humoral immunity. In regard to cellular parameters, they are composed of haemocyte count (THC), differential haemocyte count (DHC) and reactive oxygen intermediates (ROIs). The immunity ceils exert their defence functions through phagocytizing, enveloping, etc, and the changes of THC and DHC are related to health state of shrimp. The ROIs generated during post phagocytic event which maybe an important marker to evaluate the immunological capability and phenoloxidase activity have been considered as a potential marker which is relevant to the health of the shrimp too. Concerning humoral parameters, prophenoloxidase (ProPO) and phenoloxidase,antimicrobial peptides and proteins, hemagglutinin and plasma proteins were described. The determining methods of immunity parameters were discussed. The response of shrimp to pathogens such as bacteria, virus, etc. and environmental factors such as DO, pH, etc, were also reviewed. It is well-known that the immune responses induced by immunizing crustacean or shrimp are mainly the non-specific immune responses. The potential of immunological parameters, including the changes of THC and DHC, the production of ROIs, phenoloxidase (PO) activity, antibacterial activity of plasma, and so on, to appraise the healthy state of shrimp were partly discussed. The future directions for the evaluation of the immunological capability of shrimp were proposed.     

牙鲆口服A3α-肽聚糖最佳投喂方案的选择

在前期工作基础上,本实验在普通海水鱼饲料中添加了3．84g／kg（m／m）的A3α-肽聚糖（A3α—PG）,采用不同的投喂方案作用于牙鲆。以生长、溶菌酶、补体旁路激活活力（ACH50）、吞噬为评价指标,在实验期间的第14、28和42天分别取样进行测定,以评价不同投喂方案下肽聚糖制剂对牙鲆非特异性免疫力的影响。结果显示,14d内未见生长的明显差异,而在28d和42d后,4d投喂肽聚糖饲料＋3d投喂空白饲料（简称“4＋3”组）和7d投喂肽聚糖饲料＋7d投喂空白饲料（简称“7＋7”组）促生长效果最为明显（P〈0．05）。溶菌酶活力在前14d内以“4＋3”组活力最强,至28d后各实验组活力基本一致,42d时,除“7＋7”组外,各组均比对照组有明显提高（P〈0．05）。ACH50活力以1d肽聚糖饲料＋1d空白饲料（简称“1＋1”组）活力最强,在整个实验过程中均比对照组表现出大幅提高（P〈0．05）。吞噬活力在不同时间不同投喂方式下所表现出的水平有一定的波动,但从整体来看,以“4＋3”组对其诱导能力最强,前14天内,“4＋3”组与对照组及其他组相比未见明显提高,但在28d后其活力值上升较快,且维持到42d仍有较高水平。综上所述,从不同投喂方案对生长及非特异性免疫力的调节能力,并结合经济性与实用性来考虑,建议采用“4＋3”的间隔投喂方案给予牙鲆A3α-肽聚糖,以提高其非特异性免疫力和抗病力。