Relationships between body size and secondary sexual characters,and sperm characters in male Dolly Varden char (Salvelinus malma)

In Salmonidae, subordinate males are exposed to higher risks of sperm competition than dominant males and thus are expected to improve the sperm characteristics (sperm concentrations, sperm velocity and sperm longevity). In this study, we investigated the relationships between body size and secondary sexual characters (breeding colour, hump height and snout length), and sperm characteristics of one‐year‐old (newly matured) Dolly Varden char. Small males displayed higher sperm concentrations than large males. Moreover, males with dull breeding colours, but not with lesser snout length and hump height, displayed an increased sperm velocity compared to males with bright colours, suggesting a trade‐off between sperm quantity and the investment in breeding colour. In addition, sperm longevity decreased as sperm swimming velocity increased. These findings indicate that small males with dull breeding colours improve the quantity and quality of their sperm to a great extent to enhance their chances of reproductive success.     

MHC及其在动物遗传与育种方面的应用

主要组织相容性复合体(Major histocompatibility complex,MHC)不仅与移植排斥反应有关,而且还与动物的一些经济性状密切相关。文章主要阐述了MHC的结构、功能和遗传特性,并且介绍了MHC基因作为遗传标记在动物遗传与育种方面的应用。     

Breeding the mare with frozen semen

Breeding with frozen semen has become more commonplace. For a successful outcome, it is important to select fertile mares and to use quality frozen semen. The method/timing of insemination will be determined primarily by the number of semen doses available per cycle. Direct insemination of semen straws is preferred as this technique results in less loss of spermatozoa in insemination equipment. Ovulatory agents are crucial to help with timing of ovulation with respect to insemination. A post breeding examination should be performed to confirm ovulation and to examine the mare for possible complications such as post mating induced endometritis. With attention to details, frozen semen can be used with very good results.     

畜牧学科遗传育种与动物营养学面上项目申请和资助情况分析

畜禽遗传育种学和动物营养学是国家自然科学基金委员会生命科学部六处畜牧学科面上项目的重要组成部分,本文对2004—2007年畜牧学科面上项目中的遗传育种学、动物营养学和饲料资源学的申请和资助情况进行了总结,对申请和资助项目快速增长情况进行了分析,并针对2008年基金委资助格局发生变化的状况,建议项目申请者明确定位,撰写申请书时要在突出创新思想的基础上,以提出的科学问题为主线,阐明拟解决科学问题的方法和手段。本文旨在为从事该专业的科研人员申报科学基金提供参考。     

信息技术与联合育种

联合育种是加快动物群体遗传改良、提高育种效益的重要措施,是我国动物育种的必然发展趋势。信息技术是实现联合育种的必要技术支撑。本文就信息技术在联合育种的各个方面(包括性能测定、数据管理、遗传评估、人工授精体系和网络信息系统)的应用进行了综述,并对信息技术的发展(如网络技术、计算机技术、移动互联技术等)对联合育种的影响进行了展望。     

饲粮铁添加水平对产蛋期种鹅生产性能、繁殖性能、蛋品质及血液生理生化指标的影响

本试验旨在研究饲粮铁添加水平对产蛋期种鹅生产性能、繁殖性能、蛋品质及血液生理生化指标的影响,旨在探讨产蛋期种鹅对铁的需要量。选择34周龄体况相近的种鹅120只,随机分为6组,每组4个重复,每个重复5只(1公4母)。各组(Ⅰ~Ⅵ组)饲粮铁添加水平分别为0、20、40、60、80、100mg/kg。预试期1周,正试期10周。结果表明:1)Ⅴ组平均蛋重显著或极显著高于Ⅰ、Ⅱ、Ⅲ组(P<0.05或P<0.01)。由二次曲线拟合方程得出,饲粮铁添加水平为80.61mg/kg时平均蛋重最高。2)Ⅴ组种蛋合格率、种蛋孵化率和健雏率显著或极显著高于其他各组(P<0.05或P<0.01),Ⅴ组种蛋受精率显著或极显著高于Ⅰ、Ⅱ、Ⅲ、Ⅵ组(P<0.05或P<0.01)。由二次曲线拟合方程得出,饲粮铁添加水平为79.87mg/kg时,种蛋合格率最高;饲粮铁添加水平为84.82mg/kg时,种蛋受精率最高。3)Ⅴ组蛋黄色泽显著高于Ⅰ、Ⅱ、Ⅲ、Ⅳ组(P<0.05)。4)Ⅳ、Ⅴ组血清尿素氮和肌酐含量显著或极显著低于Ⅰ、Ⅱ、Ⅲ组(P<0.05或P<0.01),Ⅳ、Ⅴ组血清铁含量显著或极显著高于Ⅰ、Ⅱ、Ⅲ组(P<0.05或P<0.01)。5)Ⅴ组血液中红细胞数显著或极显著高于Ⅰ、Ⅱ组(P<0.05或P<0.01),Ⅴ组血液中红细胞压积、血红蛋白浓度、平均血红蛋白含量显著或极显著高于其他各组(P<0.05或P<0.01),Ⅳ、Ⅴ、Ⅵ组血液中平均红细胞体积显著或极显著高于Ⅰ、Ⅱ、Ⅲ组(P<0.05或P<0.01)。由此可见,饲粮铁添加水平对产蛋期种鹅平均蛋重、繁殖性能、蛋黄色泽及血液生理生化指标有显著影响,综合考虑,产蛋期种鹅饲粮铁添加水平为80.61~84.82mg/kg为宜。     

泰和乌鸡肉营养成分特征分析

泰和乌鸡因其药食同源而闻名天下,为探讨泰和乌鸡营养成分在性别之间和与其他鸡种间的差别与优势,测试分析了乌鸡的公鸡-阉鸡-母鸡之间、林下散养-笼养之间和散养乌鸡-散养小黄鸡之间鸡肉中营养成分的区别,结果表明:林下散养乌鸡具有高氨基酸、适中蛋白质和低脂肪特征,乌鸡肉中富含硒和锌、铁、锰等微量元素,不饱和脂肪酸含量高于饱和脂肪酸;呈味氨基酸含量公鸡高于母鸡,乌鸡高于小黄鸡。     

Reproduction and Development of the Released Przewalski’s Horses (Equus przewalskii) in Xinjiang,China

In China, the first Przewalski’s horse (Equus przewalskii) group was released in Kalamaili Ungulate Protected Area in Xinjiang, in August 2001. The objective of this study was to investigate reproduction and development of released Przewalski’s horses in Xinjiang, China from 2002 to 2006. Twenty-four descendants were naturally born, average reproduction rate was 38.7%, and average survival rate of foals was 69.1% in this interim. Frequent alternation of the leading stallion and infertility in female horses due to environmental factors were main causes for the low reproduction rate. The infant mortality rate of released Przewalski’s horses was 25.0%, and 83.3% of death in infants was due to the leading stallion infanticide. The released Przewalski’s horses exhibited seasonal breeding, 70.8% of infants were born in May and June. The fertility rates were 8.3% in April and 37.5% in May, which were lower compared to those of the captive Przewalski’s horse groups (18.3% and 44.3%, respectively). Furthermore, the fertility rate in June was 33.3% and higher than the captive groups (18.3%). These findings showed that the breeding peak of the released Przewalski’s horse groups was later than the captive groups, and suggested that the altered survival environment and food supplies were the main reasons contributing to the delayed breeding peak.