为全面分析绵羊繁殖周期的研究现状及变化趋势,本文采用文献计量学统计方法,分析Web of Science数据库中1936—2022年有关绵羊繁殖周期研究的4732篇文献,主要内容包括:被引文献、机构、作者、关键词、研究内容等,并使用CiteSpace 6.1 R...为全面分析绵羊繁殖周期的研究现状及变化趋势,本文采用文献计量学统计方法,分析Web of Science数据库中1936—2022年有关绵羊繁殖周期研究的4732篇文献,主要内容包括:被引文献、机构、作者、关键词、研究内容等,并使用CiteSpace 6.1 R6软件绘制网络知识图谱。结果:近年来国外绵羊繁殖周期相关发文量略有增长,我国对其关注度不断提高,相关领域科研支持大幅度提升;绵羊繁殖周期相关成果被引频次逐年增加,且与发文量成正比,各国之间有关科研领域交流正在不断增强;美国、英国、澳大利亚等国家对绵羊繁殖周期研究的成果较多,我国在该领域投入仍存在很大差距;针对主要机构及作者进行分析表明,机构、作者间的关联线比较密集;高频被引文献分析发现,绵羊繁殖周期的研究与营养需求和生理调节二者之间的关系密切;对关键词检索进行分析表明,与绵羊繁殖周期研究相关的高频热点词汇共有25个,在不同时间段,有一部分词汇会重复出现。通过以上分析,有利于加深研究前沿及成果的相互借鉴,提高绵羊养殖的效益产出,为提高我国绵羊繁殖性能提供参考和理论依据。展开更多
抱窝启动时,催乳素(PRL)水平明显提高,整个抱窝期间维持较高水平,而 E_2、P 水平较低。抱窝四季鹅注射 PRL 拮抗剂后,PRL 水平迅速下降,抱窝终止。用 PRL 拮抗剂控制抱窝,抱窝期从平均40d 缩短至8d,而对产蛋期和恢复期无影响。在为期4...抱窝启动时,催乳素(PRL)水平明显提高,整个抱窝期间维持较高水平,而 E_2、P 水平较低。抱窝四季鹅注射 PRL 拮抗剂后,PRL 水平迅速下降,抱窝终止。用 PRL 拮抗剂控制抱窝,抱窝期从平均40d 缩短至8d,而对产蛋期和恢复期无影响。在为期4个月的观察中,试验组比对照组增加一个产蛋期,产蛋量提高32.8%。提示:四季鹅抱窝与 PRL 水平提高密切有关,利用 PRL 拮抗剂可以缩短抱窝期,增加产蛋期次数,提高产蛋量。展开更多
研究了四季鹅繁殖周期中血浆β-END 和 PRL 的变化规律。结果表明:繁殖周期中血浆β-END 和 PRL 有相似的变化模式。开始产蛋时水平较低,而后逐步提高。β-END 和 PRL 分别于产蛋末期和赖抱第1d 出现较大幅度上升,并于赖抱第12d 后开始...研究了四季鹅繁殖周期中血浆β-END 和 PRL 的变化规律。结果表明:繁殖周期中血浆β-END 和 PRL 有相似的变化模式。开始产蛋时水平较低,而后逐步提高。β-END 和 PRL 分别于产蛋末期和赖抱第1d 出现较大幅度上升,并于赖抱第12d 后开始下降,直至醒抱;恢复期继续降低并维持较低水平。赖抱期四季鹅血浆 PRL,β-END 有明显的季节性变化。春季赖抱期血浆 PRL 高于秋季 P<0.01),而β-END 则以秋季较高 P<0.01);春、秋季,赖抱期的血浆 PRL 与β-END 均呈正相关。结果提示:β-END 可能参与四季鹅繁殖周期和 PRL 的调节。展开更多
Francois’ langur, the Black-headed leaf monkey (Trachypithecus francoisi francoisi), is a rare species of monkey, occurring in isolated small groups in China. Breeding periodicity of wild Francois’ langur in Mayangh...Francois’ langur, the Black-headed leaf monkey (Trachypithecus francoisi francoisi), is a rare species of monkey, occurring in isolated small groups in China. Breeding periodicity of wild Francois’ langur in Mayanghe National Nature Reserve in Yanhe County, Guizhou, China, was studied. For the subject group, known as Gandong group, they were artificial fed periodically due to shortage of natural food since August, 1997. From the latter half of the year of 1998, they were adapted to artificial feeding and fed once per day. Because of the same feeder, a trust relationship between the group and the feeder was established, and the group could be observed within fifteen meters. Through artificial feeding, Gandong group monkeys were individual recognized according to characteristics of stature, posture and appearance, and the females were differentiated by the way of F1, F2,…. The first dates of seeing newborn monkeys of the group were recorded and regarded as birth dates. The error was not beyond twenty-four hours because of daily observation and record. Birth dates of eleven newborn monkeys of Gandong group from 1999 to 2005 were recorded. The genders of the newborn monkeys were identified by observing male genitals fifteen days after born. In addition, birth dates of six other groups were combined with that of Gandong group. The six groups included Xiangguba group, Leijia group, Banqiaozi group, Shibanxi group, Dashandong group and Longdongtang group. For the six groups, the first dates of finding new baby monkeys were recorded by patrolmen who patrolled once every five days, and then verified by the authors within two days. According to characteristic of baby monkey whose hair was bright orange at first and then became gradually black one month later, birth dates of nine baby monkeys of these six groups were estimated from 2003 to 2004. The error was not beyond one week. By record, eight offspring were added into Gandong group from 1999 to 2005. At present, this group was consisted of seven males and five females, including three baby monkeys and nine non-baby monkeys. Six other groups produced nine offspring totally from 2003 to 2004. The analysis results showed that seasonal birth of wild Francois’ langur distributed from January to June, and no newborns were given birth from July to December, seventeen monkeys born from February to April in proportion with 85% in total, eight in March in proportion with 40% determined as the peak of whole year, five in April and four in February as the secondary birth peak. This distribution pattern was different significantly from that of captive Francois’ langurs whose birth failed in seasonality. Under captive conditions, food sources were secure, the surrounding was stable and there was little change of annual cycle. However it was difficult for the wild to have the above all conditions. The breeding interval of wild Francois’ langurs was 704±50 days averagely, namely twenty-three months, longer seven months than that of captive Francois’ langurs, indicating that natural environmental stresses that the wild populations were subject to might have a long-term influence on reproduction of Francois’ langurs. Meanwhile breeding periodicity was linked with difference of species, climate, habitat, and female reproductive biology.展开更多
文摘为全面分析绵羊繁殖周期的研究现状及变化趋势,本文采用文献计量学统计方法,分析Web of Science数据库中1936—2022年有关绵羊繁殖周期研究的4732篇文献,主要内容包括:被引文献、机构、作者、关键词、研究内容等,并使用CiteSpace 6.1 R6软件绘制网络知识图谱。结果:近年来国外绵羊繁殖周期相关发文量略有增长,我国对其关注度不断提高,相关领域科研支持大幅度提升;绵羊繁殖周期相关成果被引频次逐年增加,且与发文量成正比,各国之间有关科研领域交流正在不断增强;美国、英国、澳大利亚等国家对绵羊繁殖周期研究的成果较多,我国在该领域投入仍存在很大差距;针对主要机构及作者进行分析表明,机构、作者间的关联线比较密集;高频被引文献分析发现,绵羊繁殖周期的研究与营养需求和生理调节二者之间的关系密切;对关键词检索进行分析表明,与绵羊繁殖周期研究相关的高频热点词汇共有25个,在不同时间段,有一部分词汇会重复出现。通过以上分析,有利于加深研究前沿及成果的相互借鉴,提高绵羊养殖的效益产出,为提高我国绵羊繁殖性能提供参考和理论依据。
文摘抱窝启动时,催乳素(PRL)水平明显提高,整个抱窝期间维持较高水平,而 E_2、P 水平较低。抱窝四季鹅注射 PRL 拮抗剂后,PRL 水平迅速下降,抱窝终止。用 PRL 拮抗剂控制抱窝,抱窝期从平均40d 缩短至8d,而对产蛋期和恢复期无影响。在为期4个月的观察中,试验组比对照组增加一个产蛋期,产蛋量提高32.8%。提示:四季鹅抱窝与 PRL 水平提高密切有关,利用 PRL 拮抗剂可以缩短抱窝期,增加产蛋期次数,提高产蛋量。
文摘研究了四季鹅繁殖周期中血浆β-END 和 PRL 的变化规律。结果表明:繁殖周期中血浆β-END 和 PRL 有相似的变化模式。开始产蛋时水平较低,而后逐步提高。β-END 和 PRL 分别于产蛋末期和赖抱第1d 出现较大幅度上升,并于赖抱第12d 后开始下降,直至醒抱;恢复期继续降低并维持较低水平。赖抱期四季鹅血浆 PRL,β-END 有明显的季节性变化。春季赖抱期血浆 PRL 高于秋季 P<0.01),而β-END 则以秋季较高 P<0.01);春、秋季,赖抱期的血浆 PRL 与β-END 均呈正相关。结果提示:β-END 可能参与四季鹅繁殖周期和 PRL 的调节。
文摘Francois’ langur, the Black-headed leaf monkey (Trachypithecus francoisi francoisi), is a rare species of monkey, occurring in isolated small groups in China. Breeding periodicity of wild Francois’ langur in Mayanghe National Nature Reserve in Yanhe County, Guizhou, China, was studied. For the subject group, known as Gandong group, they were artificial fed periodically due to shortage of natural food since August, 1997. From the latter half of the year of 1998, they were adapted to artificial feeding and fed once per day. Because of the same feeder, a trust relationship between the group and the feeder was established, and the group could be observed within fifteen meters. Through artificial feeding, Gandong group monkeys were individual recognized according to characteristics of stature, posture and appearance, and the females were differentiated by the way of F1, F2,…. The first dates of seeing newborn monkeys of the group were recorded and regarded as birth dates. The error was not beyond twenty-four hours because of daily observation and record. Birth dates of eleven newborn monkeys of Gandong group from 1999 to 2005 were recorded. The genders of the newborn monkeys were identified by observing male genitals fifteen days after born. In addition, birth dates of six other groups were combined with that of Gandong group. The six groups included Xiangguba group, Leijia group, Banqiaozi group, Shibanxi group, Dashandong group and Longdongtang group. For the six groups, the first dates of finding new baby monkeys were recorded by patrolmen who patrolled once every five days, and then verified by the authors within two days. According to characteristic of baby monkey whose hair was bright orange at first and then became gradually black one month later, birth dates of nine baby monkeys of these six groups were estimated from 2003 to 2004. The error was not beyond one week. By record, eight offspring were added into Gandong group from 1999 to 2005. At present, this group was consisted of seven males and five females, including three baby monkeys and nine non-baby monkeys. Six other groups produced nine offspring totally from 2003 to 2004. The analysis results showed that seasonal birth of wild Francois’ langur distributed from January to June, and no newborns were given birth from July to December, seventeen monkeys born from February to April in proportion with 85% in total, eight in March in proportion with 40% determined as the peak of whole year, five in April and four in February as the secondary birth peak. This distribution pattern was different significantly from that of captive Francois’ langurs whose birth failed in seasonality. Under captive conditions, food sources were secure, the surrounding was stable and there was little change of annual cycle. However it was difficult for the wild to have the above all conditions. The breeding interval of wild Francois’ langurs was 704±50 days averagely, namely twenty-three months, longer seven months than that of captive Francois’ langurs, indicating that natural environmental stresses that the wild populations were subject to might have a long-term influence on reproduction of Francois’ langurs. Meanwhile breeding periodicity was linked with difference of species, climate, habitat, and female reproductive biology.
