舍饲安哥拉周岁公羊行为习性观察

对 6只舍饲安哥拉周岁公羊进行连续三天昼夜行为习性观察 ,结果表明 :周岁安哥拉山羊在舍饲情况下每昼夜反刍时间 (min)为 45 7 2 5± 2 4 39,睡眠时间为 2 96 5 0± 41 5 0 ,采食时间为 2 65 0 0± 2 2 31,其他时间为 15 4 2 5± 72 76。反刍与采食的时间比为 1 7∶1,明显大于正常的反刍与采食比 (0 5～ 1)的上限。反刍、睡眠和采食也与其它山羊相差较大。周岁安哥拉山羊的反刍、睡眠多发生在夜间 ,采食活动及其它一些动作如打架、自淫多发生在白天。安哥拉山羊白天排粪、排尿次数多于黑夜 ,昼夜排粪次数差异极显著。安哥拉山羊对牧草及灌木有较强的选择性 ,对饮水的卫生要求极为严格 ,拒饮不干净的水     

Historical range of variability in eastern Cascades forests,Washington, USA

The historical range of variability (HRV) has been suggested as a coarse filter approach to maintain ecosystem sustainability and resiliency. The historical range of variability in forest age structure for the central eastern Cascade Range in Washington State, USA was developed from historical fire return intervals and the manner in which fire acted as both cyclic and stochastic processes. The proportions of seven forest structural stages calculated through these processes were applied to the area of each forest series within the central eastern Cascades landscape. Early successional forest stages were more common in high elevation forest than low elevation forest. The historical proportion of old growth and late successional forest varied from 38 to 63 percent of the forested landscape. These process-based estimates are consistent with those developed from forest structural information. HRV is a valuable planning tool for ecosystem conservation purposes, but must be applied to real landscapes with consideration of both temporal and spatial scale. This revised version was published online in July 2006 with corrections to the Cover Date.     

Some determinants of the spatio-temporal fire cycle in a mediterranean landscape (Corsica,France)

Based on recent needs to accurately understand fire regimes and post-fire vegetation resilience at a supra-level for carbon cycle studies, this article focusses on the coupled history of fire and vegetation pattern for 40 years on a fire-prone area in central Corsica (France). This area has been submitted since the beginning of the 20^th century to land abandonment and the remaining land management has been largely controlled by frequent fires. Our objectives were to rebuild vegetation and fire maps in order to determine the factors which have driven the spatial and temporal distribution of fires on the area, what were the feed backs on the vegetation dynamics, and the long-term consequences of this inter-relationship. The results show a stable but high frequency of small fires, coupled with forest expansion over the study period. The results particularly illustrate the spatial distribution of fires according to topography and vegetation, leading to a strong contrast between areas never burnt and areas which have been burnt up to 7 times. Fires, when occuring, affect on average 9 to 12% of the S, SE and SW facing slopes (compared to only 2 to 5% for the N facing slopes), spread recurrently over ridge tops, affect all the vegetation types but reburn preferentially shrublands and grasslands. As these fire-proning parameters have also been shown to decrease the regeneration capacity of forests, this study highlights the needs in spatial studies (both in terms of fire spread and vegetation dynamic) to accurately apprehend vegetation dynamic and functionning in fire-prone areas.This revised version was published online in May 2005 with corrections to the Cover Date.     

The change of dry matter intake, milk yield and bone turnover in primiparous cows compared to multiparous cows during early lactation

Data from six primiparous and nine multiparous Holstein cows were used to clarify the difference of Ca and P mobilization between primiparous and multiparous cows during early lactation. The dry matter intake (DMI) of primiparous cows was lower (P < 0.01) than those of multiparous cows. Milk yield was lower in primiparous cows at 7, 14, 21 (P < 0.01), and 28 days (P < 0.05) after parturition. There was no significant difference in milk Ca and P concentrations between primiparous and multiparous cows. There were no significant differences in plasma Ca and P concentrations between primiparous and multiparous cows. The plasma P level at 7 days postpartum in primiparous cows was lower (P < 0.05) than 28 days postpartum. The concentration of plasma osteocalcin (OC) measured as bone formation marker of primiparous cows was significantly higher than multiparous cows (P < 0.01) at 21 and 28 days postpartum. The urinary deoxypyridinoline (DPD) as bone resorption marker of primiparous cows tended to be higher (P < 0.10) than multiparous cows at 21 days after parturition and decreased to the same level as that of multiparae toward the peak lactation. These results show that Ca and P mobilization of primiparous cows are more active than multiparous cows.     

赖氨酸采食量对早期断奶仔猪生长发育及胰腺内分泌机能的影响

将55头21日龄断奶的雄性仔猪随机分为5组，各组仔猪饲喂赖氨酸含量为0．60％、0．80％、1．00％、1．20％和1．40％的试验日粮21d。42日龄结束饲养试验时进行葡萄糖灌注试验，观察赖氨酸采食量对早期断奶仔猪生长发育和胰腺内分泌的影响。结果表明：早期断奶仔猪体增重与赖氨酸采食量为强正相关，根椐体增重指标，21～42日龄阶段，仔猪的赖氨酸采食量不应低于3．16g／d，日粮赖氨酸含量不应低于1.40％。赖氨酸严重缺乏(采食量小于1．45g／d)时，胰岛素的分泌量下降，对高血糖应激的反应能力降低。     

民国时期西北地区苜蓿栽培利用刍考

自汉代苜蓿引入我国以来,受到历朝历代的重视,民国时期亦不例外,苜蓿种植利用也得到了发展。在收集近现代有关苜蓿研究文献的基础上,对民国时期西北地区苜蓿种植利用情形进行了梳理与归纳,结果表明,在民国时期西北地区乃为我国苜蓿种植集中区,在陕西、甘肃、新疆、绥远(西部)、宁夏和青海等都有种植,据不完全考查,种植苜蓿的县有52个,其中以陕西最多,达22个县,甘肃次之为14个县,新疆为8个县,绥远(西部)为3个县,宁夏2县(道)和青海1个县。特别是陕甘宁边区发展苜蓿的势头高涨,如1942年边区政府在延安、安塞、甘泉、志丹、定边、靖边等县种植苜蓿达3万亩,陇东种植苜蓿2.3万亩;1944年延川县紫花苜蓿保留面积2.0万亩,到1949年,陕西全省种植苜蓿约98.49万亩。1949年新疆苜蓿保留面积达29300 hm²。绥远河套地区还进行了苜蓿粮草轮作,并建立了苜蓿种植基地。为了鼓励苜蓿种植,边区政府出台了不少政策,例如,1941年边区政府公布了《陕甘宁边区政府建设厅关于种牧草的指示信》,1942年边区政府颁布了《陕甘宁边区卅一年推广苜蓿实施办法》等,李仪祉在治理黄河的方略中,从大农业、生态环境和经济效益出发,提倡广种苜蓿,肥田养畜,并提出了4条种植苜蓿的措施。李烛尘提出,苜蓿根入土深,且能耐旱,适宜西北地区种植和培植草原。苜蓿除用于饲喂家畜外,幼嫩时可当蔬菜食用,在灾荒年也是百姓很好的救荒食物,苜蓿作为农产品常出现在兰州的市场上,试验表明苜蓿保存水土流失的作用要大于作物。     

我国明代苜蓿栽培利用刍考

苜蓿被《救荒本草》《本草纲目》《群芳谱》和《农政全书》以及明皇帝实录与方志等经典要籍所记载,充分体现了苜蓿在明代的重要性、研究的普遍性和种植的广泛性。本研究以记载明代苜蓿的相关典籍为基础,应用植物考据学原理和方法,结合现代研究成果,对明代苜蓿种植分布与状况、植物生态生物学特性、栽培管理和利用方式等进行尝试性研究考查。结果表明,明代在山西、陕西、河北、河南、山东、安徽、江苏、北京、甘肃和宁夏等省均有苜蓿种植,其中以“三晋为盛,秦、鲁次之,燕、赵又次之”。在苜蓿植物学、生态生物学研究方面成绩显著,对苜蓿植株形态、花色及其着生部位、荚果种子形状的精准描述已达到现代植物学的水准。同时,对苜蓿的轴根性也有一定的认识,记载其根的形态与黄芪的根相类似。在明代出现了紫花和黄花2种苜蓿的记载;主张苜蓿与荞麦混作,并利用苜蓿的肥田能力,将苜蓿纳入了轮作制度中;提倡7、8月种苜蓿,一年三刈,种子田一刈;苜蓿3年后生长进入旺盛期,7、8年后衰退垦去。在苜蓿饲用方面明代王象晋提出了最佳利用时期,即“苜蓿花时,刈取喂马牛,易肥健食”。同时,在苜蓿的食用、药用等方面人们利用得更加具体有效。此外,苜蓿还可做贡品。     

Contagious bovine pleuropneumonia within the 19th century miasmatic landscape

When contagious bovine pleuropneumonia (CBPP) was first detected on a farm north of Melbourne, at Bundoora, in 1858, the predominant theory of miasma was being challenged by contagionist theories of disease transmission. This well‐documented case was recorded during a period of change in the scientific assessment of disease and therefore affords an exploration of what aspects of the landscape were considered important for livestock health at the time. Although the introduction, vaccination programs and eventual eradication of CBPP on mainland Australia has been well explored, scholars have neglected this aspect of the disease's history. By comparing 19th century records of farmland with how the site appears today, it is also possible to highlight the limited information provided by contemporary texts, while at the same time developing an appreciation of the ways in which the perception of the rural landscape has changed. This differing perception has implications for the utilisation of these sources for veterinary and environmental historians seeking to understand the mid‐19th century agricultural landscape and how it relates to animal health.     

浅谈二种生活用具在棉花自交与杂交中的应用

棉花在栽培过程中,为了获得好性状的棉珠,利用自交与杂交技术进行育种,本文论述小铁夹和吸汽水管方法的精髓及注意事项。     

用户行为驱动的网页布局自动调整的研究

逻辑观是困扰当前中国逻辑史研究的根本性问题。两千多年来，逻辑的名称虽几经变化，但对命题形式、推理形式及其有效性的分析，始终是西方逻辑不变的主题。由于中国逻辑史研究是基于西方逻辑的传入而产生的，因此，西方逻辑的逻辑观应当成为中国逻辑史研究的基本遵循。