叶片与粒数及干物质积累关系的研究简报

多年的水稻苗情观察及干物质测定结果表明:同一品种干物质转化呈规律性变化,冠层叶与总粒数有明显的相关性.本文就叶面积与干物质积累,冠层叶片与每穗粒数的关系进行了初步分析.     

谷子花粉粒形态扫描电镜观察

应用电镜扫描技术对狗尾草属两个种花粉粒的形态、表面细微结构、萌发孔、孔盖以及花药内壁进行了观察.结果表明花粉粒呈圆形或近似圆形,具有一个萌发孔和孔盖,花粉粒表面有粗糙突起或星状颗粒.这些性状在栽培种和野生种之间存在差异.谷子花药内壁的星状体可作为雄性不育鉴定的一项重要形态指标.     

乙醇生产工艺对DDGS蛋白营养价值影响的研究进展

干酒糟及其可溶物(DDGS)是乙醇生产工业中的一种副产物,常常被用作动物蛋白原料使用。由于原料来源不同,DDGS的粗蛋白质含量以及粗蛋白质和氨基酸的消化率存在差异,另外,加工工艺也会影响DDGS蛋白质质量。本文综述了乙醇生产过程影响DDGS蛋白价值的因素。加热对DDGS干燥过程中的影响报道最多。在加热过程中,氨基酸会发生一系列的化学反应,导致氨基酸消化率降低或结构破坏。DDGS蛋白质质量、颜色、酸性洗涤不溶氮及氨基酸含量都是评判加热影响DDGS质量的指标。除了干燥,另外可能影响DDGS蛋白质价值的因素是在干燥和混合步骤前的高温条件。     

白酒糟对黔北麻羊羔羊饲粮养分消化率、血浆生化指标的影响

本试验旨在研究白酒糟对黔北麻羊羔羊饲粮养分消化率、血浆生化指标及抗氧化应激能力的影响。以32只体况相近的4月龄黔北麻羊羔羊为试验动物,按照随机区组试验设计分为4组:对照组和试验1、2和3组,每组8个重复,每个重复1只羊,各组饲粮白酒糟水平分别为0、7%、14%、21%。试验期40 d,其中预试期10 d,正试期30 d。结果显示:1)试验1、2组表现出较高的干物质、总能、酸性洗涤纤维、中性洗涤纤维的表观消化率,均显著高于对照组、试验3组(P0.05);粗脂肪表观消化率组间差异不显著(P0.05)。2)白酒糟对羔羊血浆生化指标的影响没有明显规律;对羔羊血浆抗氧化应激能力指标全期平均值也未产生显著影响(P0.05)。综上所述,饲粮白酒糟水平在7%~14%内可提高羔羊养分消化率,对血浆生化指标及抗氧化应激能力指标没有负面影响。     

Effects of dietary sorghum dried distiller's grains with solubles on growth performance,diet nutrient digestibility,carcass characteristics and immunity in growing rabbits

Sorghum dried distiller's grains with solubles (S‐DDGS) are distillation extract residues from the ethanol fuel industry. In this experiment, two hundred 42‐day‐old rabbits were randomly allocated to five experimental diets containing 0 g/kg (control), 75, 150, 225 and 300 g/kg S‐DDGS. The experiment lasted for 4 weeks. No difference was found in the average daily feed intake (ADFI; p > 0.05). With increasing sorghum inclusion, the average daily gain (ADG) was linearly (p < 0.001) and quadratically (p = 0.039) reduced, while, conversely, the feed conversion ratio (FCR) linearly (p < 0.001) increased. Increasing the amount of S‐DDGS in the diet linearly decreased (p < 0.001) the apparent total tract digestibility (ATTD) of dry matter (DM), organic matter (OM), crude protein (CP) and ash. Carcass weight, carcass yield, heart and liver weights were linearly decreased by an increase in the amount of S‐DDGS added to diets (p < 0.001), but no difference was observed between the 0, 75 and 150 g/kg S‐DDGS groups (p > 0.05). Serum IL‐6, IL‐10 and SIgA linearly increased (p = 0.008) with increasing levels of S‐DDGS in the diet. Rabbits fed 0, 75 and 150 g/kg of S‐DDGS had similar IL‐6 and IL‐10 levels. Statistically significant differences in SIgA were observed between rabbits fed control diets and feed mixtures containing S‐DDGS (p < 0.01). To conclude, S‐DDGS can safely be added up to 75 g/kg, to the diet of rabbits. Increasing dietary S‐DDGS inclusion may decrease the growth performance, nutrient digestibility and carcass traits, and activate immune responses.     

The efficacy of using exogenous enzymes cocktail on production,egg quality,egg nutrients and blood metabolites of laying hens fed distiller's dried grains with solubles

An experiment was performed using 120 Hisex Brown laying hens for evaluating the effects of different inclusion levels of corn distiller's dried grains with solubles (DDGS) as a replacement of soybean meal (SBM) with or without enzyme cocktail on performance, egg quality, egg nutrients and blood metabolites in laying hens through 22–42 weeks of age. A 4 × 2 factorial design experiment was performed including four substitution levels of DDGS (0, 250, 500 and 750 g/kg respectively) and two enzyme cocktail levels (0 and 250 mg/kg diet). The used enzyme in this study “Gallazyme” composed of xylanase, Trichoderma longibrachiatum (600 units/g), protease, Bacillus subtilis (8,000 units/g) and amylase and Bacillus amyloliquofaciens (800 units/g). The control diet showed the best feed efficiency followed by the intermediate levels of DDGS. The lowest value of feed efficiency was found in the group fed the highest level of DDGS. Enzyme addition improved feed efficiency and decreased laying rate. Increasing DDGS levels was associated with albumin and shell thickness increases. Dietary DDGS depressed all egg components except the organic matter which maximised in enzyme‐treated groups. Increasing DDGS level was accompanied by increase in yolk cholesterol and total lipids. No significant impacts were detected with enzymes supplementation on yolk lipids profile. Excepting serum calcium and phosphorous, all serum constituents increased with increasing level of DDGS. Using enzyme markedly depressed serum ammonia by 15.02% and increased calcium by 6.44% compared with enzyme‐free diets. Interaction between DDGS and enzyme was significant on most of studied parameters. It could be concluded that using enzyme cocktail in DDGS‐based diets may improve feed efficiency and egg quality, in addition to lowering blood ammonia and increasing blood calcium. It is recommended to substitute SBM by DDGS up to 500 g/kg diet.     

诱变与杂交结合选育超高产小麦品种的效果

为了培育超高产小麦优良品种,提出了用辐射诱变亲本,提高小麦亲本之间的遗传差异,从而增强杂交优势的理论。2003~2004年用X射线连续2年照射处理上一年处理播种出的小麦干种子。2005~2007年用高能X射线"放疗"和核磁共振双重处理,连续重复处理3年,在2007年获得大量多种类型的畸形突变植株。利用这些突变材料作为亲本,与大田中表现好的正常植株进行杂交。在杂交后代中又出现了大量的畸形突变植株,从中选出了大粒和超大粒小麦材料。这可能是突破了大粒性状和高秆性状的基因连锁关系,出现了大粒中秆和大粒低秆材料。这一理论的技术实践和材料的获得,为小麦杂种优势的诱发利用开辟了新的思路和方法,也为选育超级小麦品种创造了丰富的选种和育种材料。     

1988—2017年中国基本农田保护研究动态演化分析

为全面探讨基本农田领域研究态势，该研究采用CiteSpace软件对近30年（1988-2017年）发表的基本农田主题研究领域1 338篇文献进行了可视化分析，研究结果表明基本农田主题研究集中分布在保护、评价、划定和建设4个聚类组团。其中，基本农田保护领域重点突出了对基本农田数量、质量和生态环境的保护研究态势，基本农田评价领域强调结合现代信息技术的基本农田评价体系和评价方法模型的构建，基本农田划定研究重点分析了基本农田保护区和永久基本农田划定的理论和实践发展态势，基本农田建设领域重点研究了不同尺度下高标准基本农田建设时序、分区、标准和模式。近30年基本农田主题领域研究态势表明，基本农田内涵、评价和划定理论和方法在不断丰富和完善，基本农田研究已成为耕地保护领域关注的热点，最后建议加强该领域多学科协同研究和相关基金项目支持。     

Digestibility of phosphorus in growing pigs as influenced by source and concentration of dietary phosphorus and collection site

The current study examined the influence of source and concentration of dietary phosphorus (P) on the apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of P in growing pigs. Eighteen cannulated barrows (25 ± 5 kg) were allotted to a triplicate 6 × 3 incomplete Latin square design with six diets and three periods. The diets comprised of soybean meal (SBM) or distillers' dried grain with solubles ( DDGS) as sole sources of dietary P, and three concentrations of P (2.0, 2.5 or 3.0 g/kg) in a 2 × 3 factorial arrangement. The AID and ATTD of P were not different (p = 0.37) in all diets. Apparent digestibility of P was affected (p < 0.01) by source and concentration of P. There was no interaction between source and concentration of dietary P on the apparent digestibility of P. Determined by regression analysis, the true ileal digestibility of P was 58.3% or 57.6%, and true total tract digestibility of P was 56.0% or 62.6%, for SBM or DDGS, respectively. The regression-derived ileal endogenous P loss (EPL) was 0.61 or 0.13 g/kg DM intake, and total tract EPL was 0.53 or 0.35 g/kg DM intake, for SBM or DDGS, respectively. In conclusion, the study demonstrated that both the source and concentration of dietary P affect the digestibility of P in growing pigs.