放牧和刈割对草甸草原中小型土壤动物群落的影响          下载免费PDF全文

赵巴音那木拉  兴安  刘鹏飞  哈琴  德海山  红梅  美丽 《中国土壤与肥料》2023,(3):218-225

为了解放牧和刈割对草甸草原中小型土壤动物群落结构的影响,于2019~2020年在内蒙古呼伦贝尔市鄂温克旗贝加尔针茅草甸草原采用自由放牧、刈割和围封3种不同草地利用方式下,研究了内蒙古草甸草原中小型土壤动物群落结构特征。调查研究在草地返青期、生长期和枯黄期3个时期进行,共捕获中小型土壤动物284只,隶属于12目34个类群。结果表明:放牧导致中小型土壤动物数量、类群数和多样性指数降低,而刈割影响相对较轻;返青期、生长期、枯黄期对应的春、夏、秋三季中小型土壤动物群落结构存在明显差异,土壤动物个体数、类群数和多样性指数均在草地枯黄期最多。放牧和刈割利用方式下改变了草甸草原中小型土壤动物在草地生长期Shannon-Weiner指数、Margalef指数、Pielou指数的变化趋势。中小型土壤动物群落表聚性在刈割利用方式中表现最为典型,放牧利用方式下0~10 cm土层中小型土壤动物有向10~20 cm 土层移动趋势;土壤pH和速效钾含量与中小型土壤动物类群有密切关系。  相似文献   

Pre-weaning morbidity and mortality of llamas and alpacas     

MS Sharpe  LK Lord  TE Wittum  DE Anderson 《Australian veterinary journal》2009,87(1-2):56-60

Objectives   To describe the morbidity and mortality patterns and identify factors associated with morbidity in pre-weaning llamas and alpacas.
Design   Cross-sectional observational study of 287 crias born on four farms in Ohio, USA
Procedure   Historical data representing all crias born over a 6-year period were obtained from two llama farms and two alpaca farms in Ohio. Multivariable generalised linear mixed effects regression models were used to identify factors associated with morbidity outcomes.
Results   In total, 105 (37%) of the llamas and alpacas had some reported morbidity during the pre-weaning period, and mortality rate was 2.1%. In addition, 51 (18%) of llamas and alpacas experienced morbidity because of infectious disease, and 47 (16%) experienced morbidity during the neonatal period. The three most commonly reported morbidity events were undifferentiated diarrhoea (23%), umbilical hernia (16%) and unspecified infectious disease (15%). Difficult birth was an important risk factor for pre-weaning morbidity in this population.
Conclusions   Camelid veterinarians and their clients can expect that pre-weaning health events are common among crias, although mortality is low. Crias experiencing difficult births may require additional monitoring for health events during the pre-weaning period.  相似文献   

Advances in Reproductive Science for Wild Carnivore Conservation     

P Comizzoli  AE Crosier  N Songsasen  M Szykman Gunther  JG Howard  DE Wildt 《Reproduction in domestic animals》2009,44(S2):47-52

Knowledge about reproduction is critical for predicting the viability of wildlife populations in nature and for managing breeding programmes in captivity. Intensive species-based studies are the priority, because reproductive mechanisms are extraordinarily diverse, even within the same taxonomic family. Carnivores deserve more attention as such species are highly vulnerable to environmental change and human persecution. The present review provides contemporary illustrations of how reproductive science is contributing to understand unique reproductive mechanisms that are both of fundamental and applied interest. In the case of the endangered African wild dog ( Lycaon pictus ) free-living in South Africa, non-invasive faecal corticosteroid assessments have yielded new insights about the impact of animal relocation and reintroduction on adaptive responses, reproductive fitness and survival. For the maned wolf ( Chrysocyon brachyurus ), advances have been made in characterizing and comparing reproductive traits in free-ranging vs captive individuals. For the cheetah ( Acinonyx jubatus ), recent studies have focused on the cryosensitivity of sperm and the ability to develop a field-friendly sperm cryo-method. The by-product has been a large-scale frozen repository of sperm from wild-caught cheetahs useful for infusing new genes into ex situ populations. Finally, rigorous, multi-disciplinary and cross-institutional reproductive studies of the black-footed ferret ( Mustela nigripes ), including the use of artificial insemination, have contributed to the remarkable recovery and restoration of this species, once on the brink of extinction. In summary, advances in reproductive science are not necessarily related to 'assisted breeding'. However, understanding the unique ways of carnivore reproduction greatly contributes to species management and conservation.  相似文献   

动物生物反应器的应用现状     

于致新  肖定福  胡雄贵  邓缘  燕海峰 《畜禽业》2008,(10)

简要介绍了国外制作转基因动物的常用方法,如显微注射法、逆转录病毒介导法、配子介导法、干细胞法和核移植法等方法和原理及应用上的优劣。并综述了动物生物反应器的分类及其在生产中应用的范围和效果,概括了目前国外在动物转基因生物反应器上取得的成果,为我国动物生物反应器的研究提供技术依据。  相似文献   

羊卓雍错细菌培养及其水体理化影响因子研究     

王艳红  郝兆  郭小芳  德吉 《水生态学杂志》2022,43(3):86-95

摘要：开展羊卓雍错水体可培养细菌多样性研究,探究水体理化因子对水体可培养细菌多样性的影响。采用平板涂布法从羊卓雍错10个样点中分离细菌,结合16S rDNA区域序列分析和经典分类法对细菌菌株进行鉴定,运用R 3.6.1和SPSS 20.0等软件分析细菌多样性及其与理化因子之间的关系。结果显示,从羊卓雍错水体中共分离得到322株细菌,分属于12个属15个种,优势种为Aeromonas salmonicida、Raoultella terrigena以及Escherichia coli,分别占总菌株数的24%,22%和12%。相关性分析显示,羊卓雍错各样点水体可培养细菌总丰度与水体化学需氧量呈极显著正相关,与水体浊度、总氮呈显著正相关;各区域水体可培养细菌属数与水体电导率、总溶解固体量以及盐分含量呈显著正相关。本研究表明,羊卓雍错水体细菌资源比较丰富,水体可培养细菌多样性受水体理化因子与人为活动共同影响。  相似文献   

Digestive enzyme responses of tambaqui (Colossoma macropomum) fed on different levels of protein and lipid     

L.C. DE ALMEIDA  L.M. LUNDSTEDT  & G. MORAES 《Aquaculture Nutrition》2006,12(6):443-450

The adaptation of digestive proteases, amylase and lipase was studied in tambaqui fed with 350, 253, 301 and 205 g kg^?1 of crude protein, and 49, 81, 113 and 145 g kg^?1 of lipid, in isocaloric diets. Digestive protease increased when dietary protein increased in stomach, where the highest specific activity was observed. Unspecific protease activity in intestine was very low. Lipase was observed throughout the gastrointestinal tract, and higher activities were observed in the stomach. However, pyloric caecum and the anterior and posterior intestines were the responsive sections to the dietary lipid. Amylase was detected throughout the gastrointestinal tract, but pyloric caecum was the most relevant amylase producer. Positive correlations were observed between anterior intestine lipase versus dietary lipid and pyloric caecum amylase versus dietary protein. Tambaqui is responsive to the food composition adapting the main digestive enzymes to the best profile.  相似文献   

青海省青贮玉米链格孢叶枯病病原菌鉴定及其致病力分析     

祁鹤兴  芦光新  李宗仁  徐成体  德科加  周孝娟  王英成  马桂花 《草业学报》2021,30(6):94-105

青贮玉米是青海省玉米发展的优势产业,但是链格孢叶枯病的发生对青贮玉米的品质和产量造成了影响.为了对青贮玉米链格孢叶枯病病原菌进行鉴定及对其致病力进行分析,本研究从青海省不同海拔高度青贮玉米种植区采集病叶,从中分离得到177株病原菌,根据菌落和孢子等的形态特征和rDNA-ITS序列分析对病原菌进行鉴定;根据对金皇828、...  相似文献   

牧草捆裹青贮技术的试验研究   总被引：13，自引：1，他引：13  

徐成体  德科加 《草业科学》1999,16(4):11-13

牧草捆裹青贮是近年来在国外广泛推广和应用原一项青贮新技术。笔者着重对捆裹青贮的工艺,技术要求和配套机具进行了研究,并对捆裹青贮的草捆进行了质量综合分析评价。  相似文献   

Na2CO3胁迫对牧草苗期生理特性的影响   总被引：7，自引：2，他引：7  

苏慧  沈秀瑛  程伟燕  张永亮  德力格尔 《草业科学》2005,22(6):46-48

研究了Na2CO3胁迫下5种禾本科牧草苗期的叶片相对含水量、电解质外渗率、脯氨酸含量、叶绿素含量的变化情况,并对供试牧草耐盐性强弱进行评价.结果表明,5种牧草的耐盐性强弱顺序为:野大麦Hordeum brevisubulatum＞披碱草Elymus dahuricus＞肥披碱草E.excelsus＞老芒麦E.sibiricus＞无芒雀麦Bromus inermis;电解质外渗率、脯氨酸含量与Na2CO3胁迫浓度呈正相关关系,耐性强的草种二者增加的幅度大;相对含水量、叶绿素含量与Na2CO3胁迫浓度呈负相关关系,耐性强的草种二者下降的幅度小.  相似文献   

不同种源胡枝子抗寒性和生物量变异研究   总被引：3，自引：0，他引：3  

德永军  陈晓阳  张秋良  刘美  赵利民  代海燕 《内蒙古农业大学学报(自然科学版)》2006,27(1):7-10,63

对比试验表明,不同种源二色胡枝子的抗寒性和地上部分生物量有变异,其中二色(辽·海城1)、二色(内蒙古)与二色(美)和二色(豫)之间,二色(辽·西峰2)、二色(冀)与二色(豫)之间抗寒性差异显著。综合抗寒性和生物量两个因子进行评价,二色(内蒙古)和二色(冀)、二色(辽·海城1)、二色(辽·西峰2)、二色(辽·海城2)比较适合试验地的自然环境条件。  相似文献