Nutritional management of recurrent colic and colonic impactions

Although diagnosis and treatment of horses with colic have improved in the last 30 years, horses with recurrent colic can be a diagnostic and management challenge for both owners and veterinarians, and colic remains a high priority health concern of owners (Mellor et al. 2001 ). Nutritional management of these cases is often based on previous experience combined with recommendations from the evidence‐based literature. This review will briefly summarise the aetiologies of recurrent colic and primarily focus on evidence‐based nutritional management of colonic impactions, sand enteropathy, inflammatory bowel disease, and idiopathic recurrent colic, which is limited. Additional topics to be covered elsewhere in this series that are relevant to this topic include nutritional management of gastric ulceration, liver disease, colitis, geriatric horses, and feeding the horse pre‐ and post surgery.     

PEG胁迫下新疆地区狗牙根种子的萌发特性

为了解狗牙根(Cynodon dactylon)种质芽期抗旱性强弱,并筛选出适宜鉴定抗旱性的PEG浓度,分别对6份狗牙根种子在0、7.5%、15.0%、22.5%、30.0%PEG(质量比)胁迫下的发芽率、发芽势、发芽指数、胚芽长、胚根长、根芽比、苗重进行测定,并采用隶属函数法对其抗旱性进行了综合评价。结果表明,随着干旱胁迫的增加,狗牙根种质的发芽势、发芽率、发芽指数均显著降低(P0.05),且不同指标出现显著降低的PEG浓度并不一致;高浓度PEG抑制了狗牙根种质的胚芽长、胚根长、根芽比、幼苗重(P0.05),而低浓度对其影响不显著(P0.05);15%的PEG可作为狗牙根芽期抗旱鉴定的最适处理浓度;隶属函数综合分析认为,6份狗牙根的抗旱性由强到弱依次为Cd016Cd043Cd047Cd002Cd034Cd013。     

江苏麦田杂草群落的数量分析

用七级目测法调查江苏150个样点麦田草害情况,应用主成分分析对江苏省麦田杂草群落进行了研究。结果表明,决定江苏麦田杂草发生、分布和危害的主要因素是地带性气候 土壤性质因素。将150个样点划分为5个聚类群,即江南稻茬麦田、宁镇扬丘陵旱茬麦田、沿海旱茬麦田、徐淮旱茬麦田和沿江及苏北稻茬麦田聚类群,根据综合草害指数和发生频率明确了各聚类群相应的优势杂草,并就该地区麦田杂草发生的特点提出了治理的建议。     

Variability of the seeds and cones and key taxonomic characters selection ofLarix in Northeast China

The paper presents the results of biometrical study of the seeds and cones of larch taxa from Northeast of China. Fourteen characters are considered and their analyses showed that the seeds and cones of the larch taxa were relative greatly variable. Cluster analysis and principal component analysis for all 6 larch taxa were made. The analysis results proved that the dominant larch population in Toudao Farm fell within the range of variation ofLarix olgensis. The key taxonomic characters are the length of seed wing, length of cone, length of seed, the length/width ratio of seed and number of scales. This research was supported by Natural Science Foundation of Heilongjiang Province.(C9515) Responsible Editor: Chai Ruihai     

杂种小麦产量结构优化模式的研究

以杂种小麦产量因素及产量间的现有内在关系为基础,对８２５０－１２０００ｋｇ／ｈｍ＾２疸水平的杂种小麦的产量结构进行了优化,获得了若干产量结构优化模式。分析结果表明,目前和近期目标产量水平的杂种小麦产量结构诮在一定群体穗数的基础上增加穗粒数和千粒重,特别是注意穗粒娄和提高。文中建立的不同产量水平条件下产量结构的最优模式既有一定的多样性,同时又具有一定的规律性变化。     

抽穗期高温对水稻产量构成要素和稻米品质的影响及其基因型差异

田间条件下,采用远红外增温设施,在水稻抽穗期对6个品种进行高温(40℃)处理,以探讨全球气候变暖情况下,极端高温对水稻产量构成要素和稻米品质的影响及其基因型差异。结果显示:水稻抽穗期高温会显著降低水稻结实率,高温处理下6个水稻品种的结实率平均比常温对照下降25个百分点以上,但对穗粒数和千粒重影响不显著;高温也显著(P<0.05)降低稻米的整精米率,提高稻米的垩白率和垩白度,但对糙米率影响不显著。尽管各品种对高温的响应表现出显著的基因型差异,但是高温对所有品种的产量和品质均产生了严重影响。因此,培育耐热品种是解决热害的技术途径之一,但近期内,关键在于进行种植制度调整与栽培技术创新,以提高植株生态避热和生理抗热能力。     

几种烟熏茶的香气组成

河西园茶、沩山毛尖和湘尖茶是我国湖南地区典型的烟熏茶类。本文用气相色谱和色—质联用技术鉴定了以上烟茶的香气成分,同时也比较了它们在香气组成上的差异。结果表明,烟熏茶叶的香气特性由原料茶自身固有的成分和由特异工艺加工产生的二次产物,以及茶叶吸附的烟气成分3部分构成。     

硫营养对小麦、玉米碳、氮代谢中几项生理参数的影响

人工控制条件下生长的小麦、玉米分别培养在含0、0.5、1.0和2.0mM SO_4~(-2)4个硫营养水平的Hoagland 培养液中,对2—6周龄的植株进行了 RuBPCase、PEPCase、NR 的活性,叶片可溶性蛋白质含量,叶绿素 a 和 b 含量以及植株最终叶面积和总干重的测定。结果指出,硫营养不足影响了作物的碳、氮代谢,随着供硫量的增加,上述各参数值     

土壤pH值对茶树生长及矿质元素吸收的影响

采用盆栽法,研究了土壤不同 pH 值对茶树生长、茶叶品质成分含量和矿质营养元素吸收的影响。结果表明:茶树生长的最适 pH 是5.0—6.0,最佳 pH 值为5.5。在土壤 pH 5.5条件下,茶叶中水浸出物含量最高,氨基酸、茶多酚和咖啡碱含量也较高。茶树对矿质元素铝、锰、钙、钼、硼的吸收也以 pH 5.0—6.0最为有利。因此,茶园土壤的最适 pH 应是5.0—6.0,最佳 pH值为5.5,但在该 pH 范围内要注意增加锌肥的施用。     

树木营养诊断法综述

按笔者在国外期间收集到的科技文献,有关树木营养诊断法概括起来有5种,即土壤分析法、缺素症状肉眼观察法、植物组织分析法、养分元素综合平衡诊断法、缺素的超显微解剖结构诊断法,这些方法可互相参照,进行综合诊断。