Effects of cow manure and sewage sludge on the activity and kinetics of <Emphasis Type="SmallCaps">l</Emphasis>-glutaminase in soil

A study was conducted to investigate the effects of cow manure and sewage sludge application on the activity and kinetics of soil l-glutaminase. Soil samples were collected from a farm experiment in which 0, 25, and 100 Mg ha⁻¹ of either cow manure or sewage sludge had been applied annually for 4 consecutive years to a clay loam soil (Typic Haplargid). A chemical fertilizer treatment had also been applied. Results indicated that the effects of chemical fertilizer and the solid waste application on pH in the 18 surface soil (0–15 cm) samples were not significant. The organic C content, however, was affected significantly by the different treatments, being the greatest in soils treated with 100 Mg ha⁻¹ cow manure, and the least in the control treatment. l-Glutaminase activity was generally greater in solid-waste applied soils and was significantly correlated (r = 0.939, P < 0.001) with organic C content of soils. The values of l-glutaminase maximum velocity (Vmax) ranged from 331 to 1,389 mg NH₄ ⁺–N kg⁻¹ 2 h⁻¹. Values of the Michaelis constant (K _m) ranged from 35.1 to 71.7 mM. Organic C content of the soils were significantly correlated with V _max (r = 0.919, P < 0.001) and K _m (r = 0.763, P < 0.001) values. These results demonstrate the considerable influence that solid waste application has on this enzymatic reaction involved in N mineralization in soil.     

Climatic Changes and Emerging Diseases

The relationships between welfare and udder health indicators were investigated in 120 midlactation Comisana ewes over a 90-day period. The welfare indicators monitored were the humoral response to chicken egg albumin (OVA), the cell-mediated immune response to phytohemagglutinin, and the plasma cortisol levels. Changes in milk components, in somatic cell count (SCC) and in bacterial count, in leukocyte populations and in anti-OVA IgG concentration were used to monitor the ewe udder health. Correlations between welfare and udder health indicators were then tested. The skinfold thickness, representative of the cell-mediated immune response, was correlated positively with the percentage of neutrophils in milk and negatively with the chloride content, the percentage of lymphocytes and anti-OVA IgG concentrations in milk. The plasma antibody titres to OVA, representative of the humoral immune response, correlated positively with the anti-OVA IgG levels in milk and negatively with the lactose content and to the percentage of neutrophils. Plasma cortisol levels correlated positively with the chloride content in milk. Our study demonstrates that information about the immune condition of animals can be successfully achieved by monitoring the immunological responses of the mammary gland. The detection of reliable indicators of animal welfare in milk can help in reducing the stress from animal handling and blood sampling from lactating animals.     

自走式青稞联合收获打捆一体机参数优化与试验

为进一步研究提升自走式青稞联合收获打捆一体机工作性能,结合课题组前期研究基础与试验结果,以样机前进速度、纹杆-杆齿组合滚筒转速、脱粒间隙和打捆装置主动带轮转速为自变量,籽粒破碎率、碎芒率和成捆率为响应值,依照Box-Behnken试验设计原理,采用四因素三水平响应面分析方法,分别建立了各因素与籽粒破碎率、碎芒率和成捆率之间的数学模型,并对各因素及其交互作用进行分析。结果表明：4个因素对籽粒破碎率影响的主次顺序为纹杆-杆齿组合滚筒转速、脱粒间隙、样机前进速度和打捆装置主动带轮转速;对碎芒率影响的主次顺序为纹杆-杆齿组合滚筒转速、样机前进速度、脱粒间隙和打捆装置主动带轮转速;对成捆率影响的主次顺序为打捆装置主动带轮转速、脱粒间隙、纹杆-杆齿组合滚筒转速和样机前进速度。该一体机最佳工作参数为：样机前进速度为1.95 m·s^-1,纹杆-杆齿组合滚筒转速为864 r·min^-1,脱粒间隙为13 mm,打捆装置主动带轮转速为600 r·min^-1。田间验证试验表明,自走式青稞联合收获打捆一体机作业的籽粒破碎率均值为1.32%、碎芒率均值为97.58%、成捆率为98.36%,表明在优化工作参数条件下一体机能够降低青稞在机械化收获过程中的籽粒破碎,解决了青稞机械化收获中不易碎芒、秸秆回收劳动强度大的难题。     

不同工况下砂石过滤器对黄河水和再生水过滤性能影响

为了了解不同水源条件下砂石过滤器的过滤性能,选取黄河水及再生水2种典型滴灌水源,测试了3种粒径石英砂滤料,5种滤速条件下砂石过滤器颗粒物去除率和水头损失,重点对比了2种水源下砂石过滤器过滤性能的差异.研究发现:砂石过滤器对再生水的浊度去除效果优于黄河水,浊度去除率提高5.95%~65.30%.在黄河水条件下,砂石过滤器水头损失大于再生水,水头损失增加了34.90%~68.40%;随着运行时间的增加,砂石过滤器对再生水的浊度去除率缓慢上升,而对黄河水的浊度去除率呈先升后降趋势;随过滤流速增加,砂石过滤器对再生水的浊度去除率呈先增后减趋势,而对黄河水的浊度去除率随流速增加并未有明显变化;黄河水条件下砂石过滤器的过滤参数建议选择粒径1.00~1.70 mm,过滤流速0.012 m/s,再生水建议选择粒径1.70~2.35 mm,过滤流速0.015 m/s.结果为不同水质条件下过滤器的选择提供一定参考.     

基于轻量化YOLOv5s的花椒簇检测研究

针对现有花椒簇检测算法模型参数量多、计算量大、检测速度低、很难部署到嵌入式设备的问题,提出一种基于轻量化YOLOv5s的花椒簇检测算法模型。首先将ShuffleNet v2主干网络替代原YOLOv5s中的主干网络进行重构;同时将SPPF嵌入至ShuffleNet v2骨干中;其次引入轻量级注意力机制CBAM;最后使用SIoU_Loss代替CIoU_Loss作为回归损失函数。试验结果表明：改进后的轻量化YOLOv5s网络参数降低85.6%,计算量降低87.7%,对花椒簇的检测精度mAP@0.5达到92.6%,较原YOLOv5s模型提高3.4%,mAP@0.5:0.95达到61.4%,检测时间为11 ms,相比原模型16 ms缩短31.3%,可以满足在现场环境下对花椒簇的检测。     

高粱挤压膨化工艺条件的研究

在单因素试验基础上,采用响应面分析法研究挤压工艺条件对高粱仁膨化特性的影响。结果表明,回归方程能较好地预测高粱膨化度随挤压工艺参数变化的规律,高粱挤压膨化的最佳工艺条件是:物料含水量25.5%,物料粒度60目,转速300 r/min,膨化温度164℃,膨化度3.22。     

五味子乙醇提取物对肉仔鸡抗氧化功能和血液生化指标的影响

[目的]研究中草药五味子作为饲料添加剂对肉仔鸡抗氧化功能和血液生化指标的影响。[方法]以五味子乙醇提取物、五味子乙醇提取物和女贞子水提取物配伍及黄霉素作为饲料添加剂,测定肉鸡血清、心脏、肝脏和肾脏组织中过氧化物歧化酶(SOD)活性、谷胱甘肽还原酶(GR)活性与丙二醛含量以及血清生化指标。[结果]五味子乙醇提取物及五味子乙醇提取物与女贞子水提取物配伍均能在不同程度上提高肉鸡抗氧化能力。[结论]结果为五味子在肉鸡饲养中的应用提供了参考。     

4ZAG-30型沙生灌木栽植机的推广应用

介绍了沙生灌木栽植机的总体结构、主要技术参数、核心部件的设计及工作原理。     

酵母锌对肉鸡生长性能及生理功能的影响

选用1日龄白羽肉鸡100只,随机分成Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ组,每组20只。Ⅰ、Ⅱ为酵母锌组,锌水平分别为50,35mg/kg,Ⅲ为硫酸锌组,锌水平为50mg/kg;Ⅳ为空白酵母组,酵母添加剂量为100mg/kg;V为基础日粮对照组。各组饲喂相同基础日粮,50d后,对生长性能、血常规、血液生化（Crea、Urea、AST、ALT、ALB）及抗氧化（抗O2-.、GSH-Px、GSH）指标进行检测。结果显示,平均日增重和料重比,21d时各组之间无显著差异（P〉0.05）,50d时与V组相比,Ⅰ、Ⅱ、Ⅳ组生长性能显著提高（P〈0.01）,其中I组最高。各组血液常规指标均处于正常范围内,但Ⅰ组红细胞数极显著高于其他组（P〈0.01）。血清中肌酐、尿素含量以及天门冬氨酸氨基转移酶和丙氨酸氨基转移酶活性各组间差异不显著（P〉0.05）,Ⅰ、Ⅱ、Ⅳ组白蛋白含量较其他组显著提高（P〈0.01）。血清抗O2-.活力、GSH含量Ⅰ组显著高于其他组（P〈0.01）,GSH-Px活力Ⅰ、Ⅱ组显著高于其他各组（P〈0.01）。结果提示,日粮添加适量酵母锌（Zn 50mg/kg）可以提高肉鸡生长性能,在一定程度上增强机体免疫机能,提高肝脏功能和机体抗氧化功能。     

Effects of dietary supplementation of synbiotic on growth performance, serum biochemical parameters and carcass composition in rainbow trout (Oncorhynchus mykiss) fingerlings

The aim of this study was to evaluate the influence of a synbiotic (Biomin IMBO) on serum parameters and feeding efficiency in rainbow trout (Oncorhynchus mykiss) fingerlings. The fish with initial average weight of 4.59 ± 0.2 g were randomly assigned to four dietary treatments for two months. The dietary treatment (0.5, 1 and 1.5 g/kg of diet) was supplemented with basal diet and non-supplemented basal diet was used as control. After two months, all treatments supplemented with synbiotic showed significant (p < 0.05) increase in final mean weight, weight gain percentage, specific growth rate, condition factor, food conversion efficiency and survival rate, compared to the control group. Among all supplemented treatments, the best result in terms of growth factors and survival was observed in the treatment supplemented with 1 g synbiotic per kilogram of diet. Furthermore, supplementation with symbiotic, specifically 1 and 1.5 g/kg, significantly (p < 0.05) increased the total serum protein, but there was no significant (p > 0.05) difference in globulin content, albumin/globulin ratio, and triglyceride content among experimental treatments. In terms of body composition, carcass protein content of fish fed with synbiotic significantly (p < 0.05) increased compared to the control. These results revealed that a feeding regime with synbiotic for two months led to a significant increase in growth performance, survival rate and feeding efficiency in rainbow trout fingerlings.