内蒙古天然草地退化成因的多因素灰色关联分析

选取内蒙古草地典型草原、草甸草原及农牧交错带典型区,通过对区域内影响草地退化的社会、经济和环境等因素进行定性分析,应用灰色系统理论的关联分析方法,以草地退化面积为参考数列,以牧草生长季积温、降水变率和年大风日数等气候因子,草地超载比例、人工种草与围栏草场面积、年割草量、畜棚与畜圈面积和牧民人均收入等人类活动因子作为比较数列,对草地退化进行了多因素关联分析。研究结果客观、定量地揭示了草地退化与各因素间的相互关系,认为草地生态系统的退化受损是气候变化和人类活动共同胁迫的结果,人类对草地的管理方式对草地生态系统具有巨大影响,人类可以通过多种管理措施来减轻牲畜对草场的压力,积极解决人与资源的平衡。     

Performance and carcass characteristics of lambs fed diets with increasing levels of <Emphasis Type="Italic">Mimosa tenuiflora</Emphasis> (Willd.) hay replacing Buffel grass hay

This study evaluated the performance and carcass characteristics of lambs fed diets with increasing levels of Mimosa tenuiflora (Willd.) hay replacing Buffel grass (Cenchrus ciliaris). Twenty-eight Santa Inês male lambs with an average body weight (BW) of 20.3 ± 1.49 kg(mean ± SD) were allocated in individual stalls and distributed in a completely random design with four treatments (0, 20, 40, and 60 g/100 g total DM M. tenuiflora hay replacing Buffel grass hay in diet) with seven replications. M. tenuiflora hay at the level of 20% dry matter (DM) total replacing Buffel grass hay increased final weight (P = 0.006), total weight gain (P < 0.001), average daily weight gain (ADWG; P < 0.001), DM intake (P < 0.001), and feed efficiency (P < 0.001). Intake of crude protein, NDF_ap, ADF_ap, ash, ether extract, total and non-fibrous carbohydrates, and total digestible nutrients presented a positive quadratic effect with M. tenuiflora hay replacing Buffel grass hay and 40 g/100 g total DM level presented greater intake. There were positive quadratic effects by M. tenuiflora hay inclusion at 20 g/100 g total DM level on slaughtering weight (P = 0.005), hot carcass weight (P = 0.002), cold carcass weight (P = 0.002), empty body weight (P = 0.001), hot carcass yield (P = 0.002), cold carcass yield (P = 0.003), and increase linear on biological yield (P = 0.003). There was no influence on cooling weight loss (P = 0.284). M. tenuiflora hay may be included in lamb diets at amounts up to 20 g/100 g total DM substitution of Buffel grass hay because increase in the nutrients intake, growth performance, and carcass characteristics.     

草本化栽培杂交桑在种茧育上的应用研究

本试验以杂交桑“沙2×伦109”为材料,以普通桑园的湖桑32号片叶育为对照,就草本化栽培杂交桑在种茧育上应用的可行性进行了探讨。结果表明,在配合施用叶面肥0.2％PGH-X的情况下,供试杂交桑在原蚕生长发育、茧质及制种成绩方面与对照区相近或持平,说明原蚕饲养采用草本化栽培杂交桑及条桑二回育形式具有可行性。使用叶面肥0.15％PGH-D可使原蚕5龄期经过延长,对家蚕生长发育表现一定调控作用。     

萧山草三黄鸡屠宰性能和肉质分析

研究对70日龄萧山草三黄鸡进行了屠宰性能和肉质性状的测定,结果显示:公鸡活重、屠体重、半净膛率和全净膛率优于母鸡,差异显著(P<0.05)。腿肌的肉色OD值、剪切力和pH值均大于胸肌,系水力小于胸肌,差异均显著(P<0.05);水分含量、粗脂肪含量大于胸肌,粗蛋白含量、粗灰分含量小于胸肌,差异均显著(P<0.05)。研究表明母鸡的肉质优于公鸡,屠宰性能则不及公鸡。     

奶牛常用饲料干物质和淀粉瘤胃降解规律的研究

以3头安装有永久性瘤胃瘘管的泌乳前期荷斯坦奶牛为试验动物，在精粗比为55：45的日粮条件下，采用Insacco法测定了奶牛常用饲料瘤胃内干物质和淀粉的降解规律。试验结果表明。不同饲料干物质和淀粉的降解率不同。能量饲料中，麸皮干物质和淀粉的瘤胃降解率高于玉米：蛋白质饲料中，干物质和淀粉的降解率由高到低顺序依次是豆粕〉胡麻饼〉棉粕：常用粗料中，玉米青贮干物质和淀粉的降解率均高于青干草。     

几种重要饲草的阴阳离子平衡分析

优质饲草是奶牛高产健康的基础。为探讨优质饲草在围产期奶牛日粮中的重要性,对紫花苜蓿、苇状羊茅、鸭茅、无芒雀麦等12个饲草样品进行了钠、钾、氯、硫含量的测定并进行了阴阳离子差(CAD)分析。结果表明:(1)饲草Na 含量的变异幅度最大,K 和S2-居中,Cl-最为稳定。K 含量最高,其次为Cl-、S2-和Na 。K 含量对CAD值的影响最大。(2)苇状羊茅、无芒雀麦和鸭茅抽穗期的CAD低于孕穗期。紫花苜蓿初花期的CAD低于现蕾期和盛花期。饲草的收获期对CAD值有一定影响。     

新合院生活的景观体验——黄骅新城家园景观设计

文章从分析现状入手,依据建筑规划所形成的空间提出了新合院的景观设计理念,并通过对道路系统、出入口、水系、植物、老年儿童活动空间等景观空间的精心组织,形成小区一心、二街、三轴、四院的景观骨架,再结合对景、框景等造园手法来打造一个简洁朴实又不失特色的小区景观。     

Biochemical properties,molecular characterizations,functions, and application perspectives of phytases

As a kind of enzyme widely existing in eukaryotic species, especially in grains and oil seeds, phytases play an important role in the degradation of some phosphates containing organic molecules. So far, phytases derived from various species have been successfully used as animal feed additives. It has also been experimentally verified that phytases have a potential use in generating crop germplasm with high phosphorus use efficiency, based on their biochemical role in releasing Pi from the phytate and its derivatives. In this paper, the biochemical properties, molecular characterizations, functions and the potential application perspective of phytases are reviewed and commented on, aiming at the further exploration of the biochemical and molecular characterizations, and promotion of the application of phytases, a kind of important enzyme possessing potential use in animal feeding and creation of high P use crop cultivars, in the future.     

Multi‐channel visual evoked potential as an ancillary tool to diagnose intraorbital optic nerve lesions

Multi‐channel visual evoked potential (MVEP) recording method was used to assist in diagnosing a 4‐month‐old Chinese Albino rabbit with an intraorbital mass. Subcutaneous MVEP of its both eyes were recorded simultaneously using 16 electrodes (4 × 4) multi‐channel array. Analysis of the cortical potential landscapes (CPL) showed that the conduction function of right eye was remarkably impaired in terms of decreased amplitudes and prolonged latencies. Specific side‐dominant distribution asymmetry of the decreased MVEP amplitudes indicated that the temporal side of the optic nerve (ON) was severely involved. Overall prolonged latencies of the CPL without side differences suggested that the functional impairment could have been caused by the mechanical compression exerted by an intraorbital mass. Surgical removal procedures confirmed that the mass was located temporally to the ON. Pathological examination provided a final diagnosis of a giant polycystic mucocele. Beyond its significance as a standard tool to assess functional changes of the visual pathway, MVEP recordings might assist locating intraorbital lesions that involve the ON by careful analysis of abnormal CPLs.