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鲟鱼流水养殖快速育成技术探究
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作者 余远帅 《农家科技(理论版)》 2020年第3期113-113,共1页
本文重点探究了鲟鱼流水养殖快速育成技术,分析了鲟鱼流水养殖快速育成技术的基础条件,探索了鲟鱼流水养殖快速育成技术的要点,希望为鲟鱼流水养殖快速育成技术在我国健康发展提供一点参考,竭力提升我国鲟鱼产量,提升鲟鱼经济效益。
关键词 鲟鱼 流水养殖快速技术 鱼种
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舍饲羊从育成阶段到成年阶段饲养管理 被引量:2
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作者 李金军 《畜牧兽医科学(电子版)》 2021年第10期40-41,共2页
育成羊又被称为断奶羔羊,是指羔羊从断奶到第1次配种前的公羊和母羊,年龄通常在3~18月内。这个阶段的羊表现为生长发育速度较快,饲料利用率极高,对营养物质的需求量较大,18月龄后公羊体重达20~25 kg,母羊可以达到15~20 kg。这个阶段如... 育成羊又被称为断奶羔羊,是指羔羊从断奶到第1次配种前的公羊和母羊,年龄通常在3~18月内。这个阶段的羊表现为生长发育速度较快,饲料利用率极高,对营养物质的需求量较大,18月龄后公羊体重达20~25 kg,母羊可以达到15~20 kg。这个阶段如果营养供给不当,会对羊群正常生长发育造成严重威胁,表现为体质较轻、躯体较为狭窄,不利于后期正常发情配种,影响养殖场生产性能,甚至会失去种用价值。育成羊是羊群的未来,培育高质量的育成羊是提升养殖效益、扩大养殖规模的关键。该文探讨舍饲羊从育成阶段到成年阶段的饲养管理要点。 展开更多
关键词 舍饲羊 育成养殖 饲养管理
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Comparison of Nucleic Acid Content among Non-diapause Pupae, Diapause Pupae and Eclosion-adult from Diapause Pupae of Papilio memnon 被引量:2
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作者 易传辉 陈晓鸣 +1 位作者 史军义 周成理 《Agricultural Science & Technology》 CAS 2009年第3期101-103,107,共4页
[Objective] The aim of this study was to provide basis for deeply understanding the diapause mechanism of Papilio memnon L. [Method] RNA and DNA content of non-diapause pupae, diapause pupae and eclosion-adult from di... [Objective] The aim of this study was to provide basis for deeply understanding the diapause mechanism of Papilio memnon L. [Method] RNA and DNA content of non-diapause pupae, diapause pupae and eclosion-adult from diapause pupae at different development stages were detected by the colorimetry. [Result] RNA content of non-diapause pupae was 4.614 0-7.946 3 μg/mg, while diapause pupae was 4.326 0-5.885 3 μg/mg and eclosion-adult from diapause pupae was 20.779 3 μg/mg at initial stage. DNA content of non-diapause pupae was 0.448 7-0.535 0 μg/mg, while diapause pupae was 0.452 0-0.828 3 μg/mg and eclosion-adult from diapause pupae was 1.727 0 μg/mg at initial stage. [Conclusion] The nucleic acid content and change is related to the development stage. 展开更多
关键词 Papilio memnon Nucleic acid content DIAPAUSE PUPAE ADULT
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Reproduction and Mortality of Re-introduced Przewalski's Horse Equus przewalskii in Hustai National Park, Mongolia 被引量:1
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作者 Usukhjargal Dorj Bandi Namkhai 《Journal of Life Sciences》 2013年第6期623-629,共7页
The reproduction rate of Equus przewalskii in this study increased from year to year showing that the wild horses have already felt comfortable in the new environment and became acclimatized successfully. Of the mares... The reproduction rate of Equus przewalskii in this study increased from year to year showing that the wild horses have already felt comfortable in the new environment and became acclimatized successfully. Of the mares which were born in Hustai National Park and successfully reached reproductive age, 24.7% first gave birth at age 3 and 55.6% of them first gave birth at age 4. The most effective age range within the breeding population was 5 to 15, 25%-89% of them giving birth and an average during 2002-2011 of 72.9%. Of the Przewalski's horses which died, 65% were foals, 9.4% subadult male, 7.7% subadult female, 7.2% adult male and 10.6% were adult females. Causes of mortality differed by age and sex although wolf attacks accounted for the predominant number of deaths among foals and subadults. Stallions usually died of bad condition and injuries but parturition problems were common causes of death among mares. The mortality rate of foals (40% in 1993-2011) is a matter of great concern since foals born in Hustai National Park are the only gain component now after the active reintroduction period came to an end. A total of 109 foals were killed by wolves in 1993-2011 but 52% of them were younger than one month. 展开更多
关键词 Przewalski's horse REPRODUCTION MORTALITY SEASONALITY wolf attack.
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