L'electrode potassium pour l'analyse des tissus vegetaux (The potassium electrode for plant tissue testing)

Abstract

A potassium specific‐ion electrode equiped with a “sensing module” was compared with atomic absorption for potassium determination in plant tissue. The potentiometric readings were stable and reproducible, and were of the same order of magnitude as those obtained by atomic absorption. The correletion coefficient obtained between the two analytical methods were highly significant; but it was higher for corn leaves, sugarbeet leaf‐blades and petioles respectively.     

HPLC法测定玉米酒糟中绿原酸的含量

采用浸提法提取玉米酒糟中绿原酸并用HPLC法测定其中的含量,采用安捷伦色C18（4.6mm×150mm,5μm）色谱柱,乙腈-0.5％磷酸溶液为流动相,流速为1.0mL·min-1,检测波长为327nm.结果表明绿原酸在0.232～2.784μg呈现良好的线性关系,玉米酒糟中绿原酸含量0.028％,平均回收率为95.80％,RSD=2.72％.试验证明了玉米酒糟中含有绿原酸,且其含量较高,为玉米酒糟的进一步开发提供科学依据.     

改性蒙脱石对黄曲霉毒素B_1和玉米赤霉烯酮的吸附研究

本试验旨在探究4种不同改性蒙脱石对黄曲霉B1(AFB1)和玉米赤霉烯酮(ZEN)的体外吸附性能。采用体外吸附试验,在霉菌毒素污染的喷浆玉米皮中添加4种改性蒙脱石,检测AFB1和ZEN的浓度变化,以探究不同种类及不同添加比例改性蒙脱石对AFB1和ZEN的吸附作用。结果表明:4种改性蒙脱石对AFB1和ZEN均有显著吸附作用,其中膨润土经十八烷基三甲基氯化铵改性制备的复合改性蒙脱石II型对AFB1和ZEN的吸附效果最好,在添加量为1%时,对AFB1和ZEN的吸附率分别为62.60%和43.38%。在本体外试验条件下,4种改性蒙脱石对喷浆玉米皮中AFB1和ZEN均具有吸附作用,可以降低喷浆玉米皮中的霉菌毒素含量,为改性蒙脱石在饲料脱毒剂的使用提供参考。     

玉米花丝多糖的提取制备与抑菌作用研究

本研究以玉米花丝为原料提取多糖。选取花丝类型、花丝和水的比例、温度和时间4个因素,采用L9(34)正交设计,两次重复。结果表明:玉米花丝多糖提取的最佳方法为:采用老花丝,花丝和水比例为1:6,60℃水浴2.5 h,提取率为3.65%。通过浓缩、离心、沉淀等过程,并去除蛋白质、色素等杂质,得到玉米花丝粗多糖。将粗多糖进行甲醇分级纯化,得到4种纯化多糖。再将4种多糖各配制成6种浓度,对活化后的8种细菌和4种真菌进行抑菌试验,测量抑菌圈直径,比较抑菌效果。结果表明:玉米花丝多糖对细菌有明显的抑制作用,对真菌也有一定的抑制作用,抑菌圈直径为11.5 mm。其中,以40%甲醇浓度,4000 r/min和45%甲醇浓度,5000 r/min进行离心分离的多糖对细菌和真菌的抑制效果较好。     

超声波预处理对全株青贮玉米品质的影响

为研究超声波预处理对全株青贮玉米品质的影响,设置空白对照组、超声处理组（5、10、15、20、25 min）和乳酸菌对照组进行青贮玉米品质研究。结果表明：15 min和20 min超声处理后,全株玉米青贮饲料感官评定属于优良级。与对照组相比,超声处理后饲料的pH和氨氮比分别降低7.71%和7.82%,乳酸和乙酸含量分别提高52.14%和97.22%,干物质、水溶性碳水化合物、粗脂肪和粗蛋白质含量分别提高6.31%、15.76%、19.65%和16.34%,中性洗涤纤维、酸性洗涤纤维和酸性洗涤木质素含量分别显著降低26.10%、22.44%和29.08%。综合以上指标,15 ~ 20 min超声处理能明显提高全株玉米的青贮质量。     

2020年底各地新玉米霉菌毒素风险分析

为了解呕吐毒素（DON）、玉米赤霉烯酮（ZEN）和黄曲霉毒素B1（AFB1）在2020年底新玉米中的污染情况,指导饲料生产企业和养殖场（户）开展霉菌毒素防控,降低霉菌毒素对饲料质量安全及养殖动物的影响,避免经济受损的风险。2020年12月在市场上采集新玉米样本225份,采用胶体金免疫层析法或上转发光免疫分析法对其霉菌毒素污染情况进行检测,依据安佑集团相关企业标准标和GB 13078-2017《饲料卫生标准》进行判定分析。结果表明：新玉米中霉菌毒素检出率为96.0%,其中DON、ZEN和AFB1的检出率分别为85.8%、87.1%和86.7%|DON、ZEN和AFB1在新玉米中的污染状况差别较大,按《饲料卫生标准》判定的超标率分别为0.0%、0.4%和11.6%|最大检测值分别为2500、534 μg/kg和＞100 μg/kg。就产地而言,山西、内蒙古、东北、安徽、山东、河南、云南、陕西等地霉菌毒素污染较重。综上,与2019年及2020年玉米霉菌毒素污染调查数据相比,2020年底新玉米污染程度较重。 [关键词] 玉米|霉菌毒素|胶体金免疫层析法|上转发光免疫分析法|污染规律     

不同播量拉巴豆与青贮玉米混播对草地生产性能及牧草品质的影响

为探究宁夏雨养区不同播量拉巴豆(Dolichos lablab)与青贮玉米(Zea mays)混播对草地生产性能和牧草品质的影响,本试验采用随机区组设计,以不同播量(0 kg·hm^-2,22.5 kg·hm^-2,45.0 kg·hm^-2,67.5 kg·hm^-2,90.0 kg·hm^-2)的拉巴豆与青贮玉米混播,并运用灰色关联度法对各处理进行了综合评价。结果表明,青贮玉米单播的鲜、干草产量分别为82.09 t·hm^-2和25.21 t·hm^-2,显著高于青贮玉米与播量为45.0 kg·hm^-2,90.0 kg·hm^-2拉巴豆混播(P＜0.05);不同播量拉巴豆与青贮玉米混播饲草的粗蛋白、粗灰分、中性和酸性洗涤纤维含量较青贮玉米单播均有不同程度的增加。经灰色关联度分析,拉巴豆播种量为22.5 kg·hm^-2与青贮玉米混播综合性状排名第一,优于其它混播处理和青贮玉米单播,可作为宁夏雨养区适宜播种量推广。     

利用近红外光谱技术快速分析全株玉米青贮营养成分

研究旨在利用近红外光谱技术(near infrared reflectance spectroscopy,NIRS)建立全株玉米青贮6种营养成分的近红外预测模型,为生产实践中合理利用全株玉米青贮饲料资源提供理论依据。选取玉米青贮样品64份作为定标集,16份作为验证集。利用NIRS结合改良偏最小二乘法(modified partial least squares,MPLS)构建并且验证其建立预测模型的优劣。结果表明:构建的玉米青贮干物质(DM)、粗蛋白(CP)、酸性洗涤纤维(ADF)和粗灰分(Ash)预测模型的交叉验证相关系数(1-VR)分别为0.83、0.80、0.93和0.78,都在0.80左右,可以用于实际预测。粗脂肪(EE)和中性洗涤纤维(NDF)含量预测模型1-VR为0.64和0.40,低于0.80,构建的模型相关性较差,模型还需要进一步优化。     

The effects of transportation stress on Japanese quail (Coturnix Coturnix japonica) fed corn‐based diet in comparison with wheat‐based diet supplemented with xylanase and phytase

Harvesting, handling and transporting quails to the slaughterhouses, other farms and laboratories might covertly reduce their welfare. The aim of this study was to evaluate the effects of two major sources of energy in poultry nutrition on reducing transportation stress in Japanese quail (Coturnix Coturnix japonica). Male quails (n = 60) were divided into two groups. The first group was fed corn‐based diet, and the second was fed wheat‐based diet supplemented with xylanase and phytase. At the end of the experiment (day 35), quails were subjected to 80 km of transportation. Immediately on arrival and after 24 h, heterophil counts, lymphocyte counts and H:L ratios were measured. On arrival, H counts were lower, L counts were higher, and H:L ratios were lower for corn‐fed group. After 24 h, wheat‐fed group showed lower increment of H counts, greater increment of L counts and also decrement of H:L ratios rather than corn‐fed group which showed increment of H:L ratios. However, these ratios were still lower in corn‐fed group. Results indicate that corn‐based diets can help Japanese quail to better resist transportation stress, although it seems that feeding wheat‐based diets supplemented with xylanase and phytase could have positive effects for coping better with stress after journeys.     

收获期对玉米茎秸产量和营养价值的影响

研究适于云南亚热带地区的玉米品种.结果表明:玉米青秸产量以蜡熟期最高,干秸产量以完熟期最高;粗蛋白质产量和产奶净能量(NEL)均以蜡熟期最高;专用青贮玉米、粮饲玉米和普通玉米蜡熟期鲜秸产量分别为108.9、111.7和127.5 t/hm2,干秸产量为33.4、36.4和40.7 t/hm2,粗蛋白质产量为2.7、2.9和3.4 t/hm2,产奶净能量为49825.8、57789.4和64430.3 Mcal/t/hm2;高产优质玉米品种为京科9号、樱红和路单4号.