Effect of Different Concentrate-roughage Ratios on Rumen Degradability of Cassava Stems and Leaves Total Mixed Ration in Goat

The rumen degradations of TMR were studied in this experiment,in which cassava stems and leaves were used as roughage and formulated with concentrate in different proportions.The purpose of this study was to formulate the available TMR for finishing goat,and provide a theoretical basis for the applications of cassava stems and leaves in goat production.Six Hainan Black goats with permanent rumen fistulas were selected,the rumen degradabilities of DM,CP,NDF and ADF of TMR with 6 different concentrate to forage ratio（2:8,3:7,4:6,5:5,6:4 and 7:3）were tested using nylon bag method.The results showed that,the DM effective degradabilities at the ratio of 4:6,5:5,6:4,7:3 were significantly higher than that of 2:8 and 3:7（P<0.05).CP effective degradabilities at the ratio of 2:8,3:7,4:6 were significantly higher than that of 5:5,6:4 and 7:3（P<0.05).The NDF effective degradation at the ratio of 5:5 was significantly higher than that in the other groups（P<0.05).The ADF degradation at the ratio of 3:7 was significantly higher than that of 4:6,5:5, 6:4 and 7:3（P<0.05).The results indicated that,the nutrient degradation in rumen were higher when the concentrate to forage（cassava stems and leaves）ratio in TMR were 3:7,4:6 and 5:5,and the recommended ratio range were 4:6 to 5:5 in production practice.     

Bird flu (H7N9) outbreak and its implications on the supply chain of poultry meat in China

During the past two decades, food safety issues in China not only posed serious threats to Chinese consumers but also damaged the image of Chinese products internationally. In China, food safety is not only about scientific discoveries, advanced laboratories, and sanitation equipment; it is more about the role of different players in the food supply chain. The poultry meat supply chain is instrumental in the spread of the avian influenza A virus (H7N9), raising questions about how policymakers respond to such threats and whether industries need to be restructured to manage and control this epidemic so that it does not recur. As a short-term measure, to prevent the spread of this disease, government authorities enforced the closure of live bird markets (LBM) in disease-affected areas of China. However, in the long term, the poultry meat supply chain needs to be restructured. The aim of the current study was to analyze distribution channels for chicken meat in China and then describe arrangements in poultry meat sectors that incorporate small- and medium-scale producers into the supply chain while responding to shifts in LBMs. We also assessed the role of LBMs in spreading H7N9 and how these interventions affect the poultry meat supply chain in the Chinese market.     

Proton accumulation accelerated by heavy chemical nitrogen fertilization and its long-term impact on acidifying rate in a typical arable soil in the Huang-Huai-Hai Plain

Cropland productivity has been signiifcantly impacted by soil acidiifcation resulted from nitrogen (N) fertilization, especialy as a result of excess ammoniacal N input. With decades’ intensive agricul...     

农五师葡萄钾素动态变化及调节措施研究

通过叶分析研究了不同葡萄品种叶柄全钾5～9月含量动态变化规律.结果表明:葡萄叶柄钾含量在生育期内整体呈波浪式下降趋势,前期下降迅速,中期平缓,进入浆果成熟期后又趋于下降；强势品种在整个生长季节内对钾的吸收大于弱势品种；早熟品种叶柄内钾含量变化趋势比晚熟品种提前.根据新疆农五师葡萄园区土壤有效钾含量分布现状,建议生产中应根据葡萄钾元素动态变化特点,不同团场应结合当地土壤有效钾含量相应补充.     

外源氮添加对湿地土壤N_2O排放量的影响

为搞清湿地土壤驱动N2O排放的关键氮源类型,有效减少湿地N2O的排放,本文通过室内控制温湿度,用气相色谱法分析不同外源氮素对湿地N2O排放的影响。结果表明:外加氮源组总是高于对照组N2O排放量(4.4 mg·m-3)。在设定的剂量范围内,单独添加尿素或尿素与硝酸铵1∶1配合时N2O排放量呈现先增后减的单峰分布趋势,峰值分别为10.6 mg·m-3和229.0 mg·m-3;单独添加硝酸铵时N2O排放量(32.6~111.0 mg·m-3)随着氮素添加量增加呈现持续上升趋势。单独添加尿素或硝酸铵、尿素与硝酸铵1∶1配合均促进N2O的排放,但硝酸铵尿素混合添加对N2O排放量的贡献单独添加硝酸铵单独添加尿素。这为预测内蒙古高原区农牧交错带湿地氮素输入可能带来的温室效应和有效减排提供科学依据。     

Evaluation of Cold Tolerance in NERICAs Compared with Japanese Standard Rice Varieties at the Reproductive Stage

New Rice for Africa (NERICA) is a general name for interspecific rice varieties derived from a cross between the high‐yielding Asian rice (Oryza sativa L.) between locally adapted African rice (Oryza glaberrima Steud.). Eight NERICAs were evaluated for cold tolerance (CT) at the reproductive stage and compared with their O. sativa parents and three Japanese standard rice varieties over 3 years. Cold tolerance was evaluated based on the filled grain ratio (FGR) after cold water irrigation. The FGR was greatly reduced by cold water irrigation. NERICA 1, 2 and 7 had higher FGR (51.9–57.9 %), while NERICA 6, 15 and 16 had lower FGR (6.2–14.5 %). NERICA 1, 2 and 7 were less affected by cold stress, with a 31 % mean reduction in FGR, while NERICA 6, 15 and 16 were greatly affected, with their FGRs being reduced by more than 80 %. NERICA 3 and 4 were moderately affected by cold stress, with about 45 % reduction rate in FGR. FGR significantly influenced the grain weights of the varieties with strong positive correlations (r = 0.83–0.91; P < 0.001), and thus, similar trends in grain weights were observed. Grain weights were reduced by 61.7–96.4 % under cold stress. NERICA 1, 2 and 7 showed significantly better performance than NERICA 3 and 4, while NERICA 6, 15 and 16 performed poorly under cold water irrigation. The Japanese varieties Koshihikari (very tolerant) and Ozora (moderately tolerant) were more affected by cold water irrigation than NERICA 1, 2 and 7. On the basis of the mean reduction rate (%) in FGR under cold stress, the varieties were classified as follows: NERICA 1, 2 and 7 as tolerant; NERICA 3 and 4 as moderately tolerant; and NERICA 6, 15 and 16 as susceptible to cold stress. However, NERICA 7 grain yields were lower under cold stress due to both greatly reduced number of panicles per plant and number of spikelets per panicle. Therefore, NERICA 1 and 2 are suitable candidates for production in the highland regions of East Africa and should be promoted for production.     

速生林木材液化及其产物应用研究

[目的]为速生桉树木材液化及其产物的应用提供参考。[方法]以硫酸为催化剂,苯酚为液化剂,对速生人工林桉树木材进行液化,并取液化产物与甲醛进行树脂化反应制备液化木基酚醛树脂LWPF,研究液比对液化反应效率、液化产物重均分子量及LWPF树脂胶合性能的影响。[结果]随着液比的提高,液化产物的残渣率及重均分子量均降低,而LWPF树脂制得的胶合板的木破率提高;当液比提高到一定程度后,液化产物的残渣率和重均分子量及LWPF树脂所制胶合板的木破率变化不明显。[结论]对速生桉树木材的液化工艺及其液化产物的树脂化合成工艺进行了优化。     

优化施肥对春小麦产量、氮素利用及氮平衡的影响

2009 ～ 2010年,在宁夏引黄灌区分别以宁春11号和宁春16号小麦为供试作物,利用田间试验研究了优化施肥(OPT)和习惯施肥(CON)对春小麦产量、氮素吸收利用和土壤硝态氮累积的影响,表观评估了土壤—小麦体系氮素平衡.结果表明,相对于CK处理,OPT和CON都显著提高春小麦籽粒产量地上部生物量,并促进籽粒N和地上...     

植物TIR1/AFBs基因家族研究进展

TIR1/AFBs基因家族是一种存在于细胞核中的生长素受体,属于F-box蛋白基因中的一个小亚族。它们通过与相关生长素相结合活化转录因子来促进基因的表达,从而进行调控,是生长素信号转导过程中的关键部分。为了深入研究生长素信号转导机制,从TIR1/AFBs基因家族的发现与结构,家族成员表达模式的差异及对植物生长发育方面的调节等方面概括介绍了TIR1/AFBs基因家族的分子调控机制,总结了TIR1/AFBs基因的功能。最后探讨了TIR1/AFBs基因的研究方向。