共查询到20条相似文献,搜索用时 109 毫秒
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<正>1分阶段精细饲养技术的应用现状为了达到精准饲养的目的,牧原食品有限公司(以下简称牧原)针对不同的季节和温度、不同的猪群设计了57种配方(表3),每周调整1次,然后依据反馈的应用结果对配方进行修正。牧原公司依据季节和温度的不同,设计了3种日粮配方,即春秋季、夏季和冬季;依据猪群的不同则设计了23种配方;种公猪和泌乳母猪不同季节用同一配方。在设计配方时主要考虑了以下四个要素:一是猪在一定季节和温度条件下的维持需要。二是猪群的生长增重,育肥 相似文献
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我国家兔疾病流行现状及防制对策 总被引:1,自引:1,他引:0
我国幅员辽阔,各地气候差异很大,加之兔舍结构、兔的品种、饲养数量、饲料配方、草料质量、饲养管理水平及经验都不尽一致,因而家兔疾病情况十分复杂。目前我国流行的家兔疾病主要有以下几种: 相似文献
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鳖是一种肉食性动物,在天然条件下,多以螺、蚌、鱼、虾为食。但在人工集约化养殖的条件下,天然饵料的来源往往不足,且天然饵料的价格也较高。这就在某种程度上限制了养鳖业的发展。而发展人工配合饲料是降低养鳖成本,满足鳖生长所需营养的必由之路。笔者介绍几种鳖的人工饲料配方,以供广大养殖户参考。配方一:日本发展人工养鳖,采用的是鳗鱼的人工饲料配方。结果,不仅雌鳖产卵多,而且幼鳖生长快,料肉比达到了3∶1。目前,我国的一些养殖场,参照鳗鱼的饲料配方配制鳖的饲料,也取得了成功的经验和良好的效果。其配方和制作方法是:鱼粉35%、麸皮… 相似文献
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内蒙古赤峰市阿鲁科尔沁旗玉米作物获丰收 《畜牧与饲料科学》2008,29(1)
阿鲁科尔沁旗是内蒙古自治区测土配方施肥项目实施单位,2007年该旗玉米作物全部应用配方肥,测土配方施肥面积达0.67万hm2,占全旗耕地面积的7.4%。2007年该旗气候干旱, 相似文献
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Marina ZANIN Noa GONZALEZ-BORRAJO Cuauhtémoc CHÁVEZ Yamel RUBIO Bart HARMSEN Claudia KELLER Pablo VILLALVA Ana Carolina SRBEK-ARAUJO Leonora Pires COSTA Francisco PALOMARES 《Integrative zoology》2021,16(1):2-18
Modern and paleoclimate changes may have altered species dynamics by shifting species’ niche suitability over space and time. We analyze whether the current genetic structure and isolation of the two large American felids, jaguar (Panthera onca) and puma (Puma concolor), are mediated by changes in climatic suitability and connection routes over modern and paleoclimatic landscapes. We estimate species distribution under 5 climatic landscapes (modern, Holocene, last maximum glaciations [LMG], average suitability, and climatic instability) and correlate them with individuals’ genetic isolation through causal modeling on a resemblance matrix. Both species exhibit genetic isolation patterns correlated with LMG climatic suitability, suggesting that these areas may have worked as “allele refuges.” However, the jaguar showed higher vulnerability to climate changes, responding to modern climatic suitability and connection routes, whereas the puma showed a continuous and gradual transition of genetic variation. Despite differential responsiveness to climate change, both species are subjected to the climatic effects on genetic configuration, which may make them susceptible to future climatic changes, since these are progressing faster and with higher intensity than changes in the paleoclimate. Thus, the effects of climatic changes should be considered in the design of conservation strategies to ensure evolutionary and demographic processes mediated by gene flow for both species. 相似文献
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多年生黑麦草顶峰的引种适应性研究 总被引:3,自引:3,他引:0
国外引进优良草坪草种———多年生黑麦草顶峰 (Pinnacle) ,在国内的 3个气候带 :北京 (北过渡带 )、兰州 (寒冷半干旱带 )和成都 (南过渡带 )等地 ,进行了品种评定和适应性的研究 ,结果表明 :多年生黑麦草顶峰适宜在中国北方过渡带和南方夏季不甚高温高湿的地区推广 ,在兰州以西越冬不理想。 相似文献
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气候变暖对高寒草甸气候生产潜力的影响 总被引:30,自引:2,他引:28
利用多年定位测定的草地生产力资料及同步气象因素观测数据,建立现实状况下光、温、水影响草地气候生产潜力模型 在分析现实高寒草旬气候生产力分布与环境条件关系的同时,根据该模型模拟计算未来气温升高2℃和4℃,降水增加10 %和20%状况下的气候生产力情景。在上述两种气候情景下,未来草地生产力分别出现降低(10%)和升高(1%)的两种可能。气候变暖在一定程度上减少和缓和低温对高寒草甸牧草生长的不利影响,但地表及植被的蒸散量的加大远比降水增加的快,水分则成为牧草生长的限制因素。 相似文献
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Li-Na Xie Hong-Yu Guo Wei-Zhong Chen Zhe Liu Song Gu Cheng-Cang Ma 《Strength and Conditioning Journal》2018,71(1):98-105
Shrubs are important plant species in grassland ecosystems worldwide, and their density and cover have been gradually increasing globally. However, the interaction effect of grazing and aridity on population recruitment and population growth of shrub species in grasslands has not been examined explicitly. We examined sapling establishment, sexual recruitment, population mortality, and population growth of Caragana stenophylla along a climatic aridity gradient and a grazing intensity gradient in the Inner Mongolia Steppe, using manipulative field experiments. Sapling establishment, sapling height, and sexual recruitment of C. stenophylla decreased as climatic aridity and grazing intensity increased. The negative effects of grazing on sapling establishment and sexual recruitment gradually increased as climatic aridity increased. The effect of climatic aridity and grazing on population mortality was influenced by sexual recruitment. In the combined treatments of climatic aridity and grazing, population mortality was relatively high when sexual recruitment was relatively high, while population mortality increased as climatic aridity and grazing increased when sexual recruitment was relatively low. C. stenophylla population increased under relatively low drought stress and mild grazing but declined under strong drought stress and/or severe grazing. Our results suggested that to maintain viable Caragana populations, appropriate grazing policies must be made according to climate aridity gradient. 相似文献
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西藏怒江流域高寒草甸气候生产潜力对气候变化的响应 总被引:7,自引:2,他引:5
根据西藏怒江流域9个气象站1980-2008年年平均气温、年降水量资料,采用Miami模型研究该流域高寒草甸气候生产潜力的地域分布以及年代际变化。结果表明,近29年西藏怒江流域气候生产潜力中上游主要受温度条件的制约,中下游主要受降水条件的制约,气候生产潜力与年降水量和主要生长季平均温度显著正相关。总体上气候生产潜力的分布存在较大的地区差异,下游地区明显高于上游地区。过去29年,由于温度的逐年升高,伴随降水的增加,气候生产潜力呈逐渐增加趋势,且增幅较明显。整个怒江流域未来90年(2011-2100年)有向“暖湿型”气候方向发展的趋势,降水将成为该流域气候生产潜力的主要气候限制因子,总体上气候生产潜力呈增加趋势,但增幅不大,未来气候对该流域畜牧业发展和生态环境改善有利。 相似文献
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凌志高羊茅在中国的引种适应性研究 总被引:5,自引:1,他引:4
国外引进的优良草坪草种-凌志高羊茅在中国有代表性的6个气候带:北京(北过渡带)、沈阳(寒冷潮湿带)、兰州(寒冷半干旱带)、昆明(云贵高原带)、上海(温暖潮湿带)和广州(热带、亚热带)进行品种的评定和适应性的研究。结果表明:除在热带、亚热带地区外,凌志在其它气候带都能很好的适应,其色泽深绿,覆盖率高,并且耐热、抗寒能力也强,是适宜在中国热带、亚热带以外的地区建植的优良草坪草种。 相似文献
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影响天山北坡中山带天然牧草产量的主要气候因子分析 总被引:3,自引:0,他引:3
对影响天山北坡中山带天然牧草产量的气候因子进行研究,得出降水是影响天山北坡中山 场牧草产量的关键气候因子这一结论,并且建立了降水量和牧草产量之间的数学表达式。 相似文献