藏鸡的现状及利用

藏鸡是一种体型较小、胸腿发达、快羽 ,适宜于高寒、低压、缺氧高海拔地区的地方优良品种 ,素以觅食能力强 ,极耐粗放 ,体小肉多、肉质细嫩鲜美而著称 ,是高海拔地区养禽业中的当家品种。针对藏鸡生产、繁育的现状和不足 ,分析其制约因素 ,研究搞好藏鸡繁育与饲养的综合配套技术以及藏鸡可持续开发利用的战略对策 ,无疑具有现实的指导意义和长远的理论意义     

Effects of Different Forced Molting Methods on Postmolt Production,Corticosterone Level,and Immune Response to Sheep Red Blood Cells in Laying Hens

The objective of this study was to evaluate the effects of different molting methods on postmolt production, plasma corticosterone levels, and antibody production to SRBC for the welfare of laying hens. This experiment was conducted with 120 IGH-type Brown laying hens (70 wk of age), randomly divided into 3 experimental groups. The hens in one group were fed a whole-grain barley diet during the first 10 d (WB diet). On d 11, hens consumed 100 g of layer diet/d until d 28. In the second group, hens were fed a Zn diet containing 10,000 mg/kg of Zn as ZnO for 10 d (Zn diet). Hens were then provided 100 g of a layer diet from d 11 to 28. In the third group, feed was withdrawn for 10 d, and on d 11 hens were fed a cracked corn diet ad libitum until d 28 (California method; CAL diet). Hens in all groups were returned to the layer diet ad libitum on d 29. Egg weight was lower in the Zn treatment than in the other treatments. Feed intake and plasma corticosterone levels were higher and antibody production was lower in the CAL treatment than in the WB and Zn groups. The FCR was better in the WB than in the Zn group. Mortality, egg production, and egg quality were not significantly different among the molting methods. As a result, the WB molting program was the best method for postmolt production among the programs examined.     

Physical activation of biochar and its meaning for soil fertility and nutrient leaching – a greenhouse experiment

The slow alteration of the surface of charred biomass (biochar) over time may contribute to an improved nutrient retention and thus fertility of tropical soils. Here, we investigated soils from temperate climates and investigated whether a technical steam activation of biochar could accelerate its positive effects on nutrient retention and uptake by plants relative to nonactivated biochar. To this aim, we performed microcosm experiments with sandy or silty soil, mixed with 2.0, 7.5 and 15.0 g/kg soil of fine (<2 mm) or coarse‐sized (2–10 mm) biochar from beech wood (Fagus sp.). After initial fertilizer (NPK), ashes and excess nutrients were leached with water, and the microcosms were planted for 142 days with Italian Ryegrass (Lolium multiflorum ssp. italicum). Thereafter, leachate, soil and plant samples were analysed for their nutrient contents. The results showed that biochar additions of ≤15 g/kg soil left elevated contents of available P and N in the surface soil but reduced their uptake into the plants. As a result, total biomass production was unchanged. Different particle size and application amounts influenced these findings only marginally. Nitrate leaching was enhanced in the sandy soil (+41% for nitrate, but reduced in the silty soil ?17%) and P was immobilized. Hence, the fertility of the temperate soils under study was only marginally affected by pure biochar amendments. Steam activation, however, almost doubled the positive effects of biochars in all instances, thus being an interesting option for future biochar applications.     

Modelling of soil nutrient budgets: an assessment of agricultural sustainability in Nepal

Abstract. Sustaining soil fertility under agricultural intensification and expansion onto marginal lands is a significant challenge in the Nepalese Middle Mountains. In a detailed watershed study it was shown that the overall soil fertility is poor, forest soils display the poorest conditions as a result of biomass removal, and sustaining agriculture is questionable due to the transformation from traditional to multiple cropping systems. Parent material is a significant factor influencing low phosphorus status while insufficient inputs create deficiencies in total carbon, nitrogen and bases. A nutrient budget model was developed to assess inputs, redistribution and losses relative to soil fertility. Yield, input and management data obtained from farm interviews, and soil analysis data were used in the calculation of nutrient budgets. Results from modelling indicate declining soil fertility under rainfed agriculture, forest and rangelands, and marginal conditions under irrigated agriculture subject to intensive cultivation. Nutrient deficits were relatively low for irrigated rice-wheat systems, which benefit from nutrient inputs via sediments and irrigation waters, but the introduction of triple cropping showed greater deficits. Nutrient balances were most critical under rainfed maize production where 94% of the farms were in deficit. Current shortages of organic matter make elimination of nutrient deficits problematic but improvement of composting, biological N-fixation and fertilizer efficiency and reducing erosion were found to be potential options.     

从构建和谐社会探索县级图书馆服务创新

县级图书馆发挥自身优势,在构建和谐社会中,大胆创新,拓宽服务领域,提高服务质量,是提升县级图书馆事业的需要,也是建设中国特色社会主义社会的需要.新时期县级图书馆服务创新,是发展图书馆事业服务于和谐社会的必由之路.     

汛期横江入流对向家坝一期围堰河段水位的顶托影响

为保证向家坝一期围堰工程汛期安全度汛,时汛期横江入流的向家坝一期河段水位的顶托影响进行了研究.研究时首先采用实测资料对横江洪水的顶托影响进行分析,在此基础上,采用BP神经网络对不同横江来流下向家坝水文站的水位变化进行预测,给出向家坝水文站的水位壅高幅度.结果表明:横江洪水对向家坝河段水位顶托影响主要发生在金沙江洪水过程的涨水段,一期围堰修建后向家坝水文站受横江来水顶托影响主要发生在屏山流量为8 OOO～17 000 m3/s,且横江流量大于1 000m3/s时的范围内,其水位壅高幅度一般在0.44～1.5 m范围内变化.     

马杜霉素和泰妙菌素联合应用对雏鸡新城疫抗体水平的影响

试验将不同剂量的马杜霉素和泰妙菌素分别添加到雏鸡的饲料和饮水中同时使用,通过检测不同组别雏鸡血清中ND血凝抑制效价,探讨马杜霉素和泰妙菌素不同剂量联合应用时对雏鸡免疫功能的影响。试验结果表明:正常推荐剂量的马杜霉素5mg/kg与泰妙菌素10mg/kg联合使用时,一般不会对机体免疫造成明显伤害;应用马杜霉素10mg/kg拌料能明显造成机体免疫系统伤害,当其与正常或加倍剂量的泰妙菌素联合应用更会加重对机体免疫功能的不良影响,致使抗体水平下降。     

危险度分级法对原油稳定装置的安全评价

根据《危险程度分级》标准对大庆天然气分公司原油稳定装置进行了安全评价。通过计算,确定原油稳定装置固有危险等级属二级,站场安全管理等级为优,实际危险等级为中度,并对评价出的潜在危险性提出了相应的安全措施。该方法考虑因素全面,评价结果符合现场实际情况。     

不同施肥水平对马铃薯品质的影响

在平地和坡地条件下,采用4种施肥水平对鄂马铃薯4号品种进行栽培试验,考察不同施肥水平下对马铃薯淀粉品质的影响.结果表明,不同施肥水平下,平地和坡地栽培马铃薯,其淀粉含量达到显著性差异,施低肥时淀粉的含量较高,随着施肥量的增加,淀粉含量随之下降;在相同施肥水平下平地较坡地马铃薯淀粉含量的变化大,说明马铃薯淀粉除受施肥量影响外,还受地形、环境的影响,坡地存在水土流失,导致坡地比平地栽培马铃薯的淀粉含量低0.89%～3.86%.因此,合理栽培、适度开发利用土地资源以及重视水土保持尤为重要.     

德系安格拉毛用兔日粮最适营养水平探讨

本试验选用德系安格拉成年毛用兔80只,研究了其日粮不同粗蛋白(CP)、含硫氨基酸(SAA)和粗纤维(CF)水平对产毛性能的影响。结果表明,日粮中CP水平以16%～18%为宜,过高的CP水平并不能提高产毛率和毛的质量;日粮中SAA水平以0.65%～0.85%为宜,日粮配方中添加一定量的蛋氨酸能显著提高产毛性能;日粮中CF水平以14%左右提高毛的产量和质量为最佳,过精的日粮不仅造成浪费,而且对产毛性能并没有好处。